De Luca PA, Stoltz JA, Andrade MCB, Mason AC. 2015. Metabolic efficiency in courtship favors males with intermediate mass in the Australian redback spider, Latrodectus hasselti. Journal of Insect Physiology 72: 35–42. ==> Abstract & PDF [PDF入手には龍大図書館・データベースのScienceDirectから入りなおす]|
Recent studies have suggested that metabolic efficiency may be an important factor in male mating success when females require vigorous and/or prolonged courtship. In capital breeding animals in which a male’s resource pool is fixed at adulthood the relationship between energy expenditure and courtship performance may be especially important, as males are expected to utilize their finite resources efficiently when soliciting mates. Males may benefit from being efficient, i.e., achieving a sufficiently high level of courtship signaling at low energetic cost, if it enables them to acquire mates before their limited energy reserves are depleted. We investigated the relationship between metabolic efficiency and courtship vibrational signaling in the Australian redback spider, Latrodectus hasselti, a semelparous capital breeder where males invest heavily in courtship to secure a mating. We assessed metabolic rate in a sample of males and measured two courtship components (duty cycle and amplitude) that reflected the energy content of web-borne vibrations. We then calculated two indices of metabolic efficiency for these courtship properties. There was a quadratic relationship between mass and duty cycle such that the highest duty cycle signals were performed by males having intermediate mass. Furthermore, intermediate-mass males were also the most metabolically efficient. Prolonged courtship is necessary in L. hasselti for successful mating, and the results of this study suggest that intermediate-mass males are superior courters because they utilize their finite resource pool most efficiently to produce high energy vibrational signals.
Antoniou GN, Iliopoulos D, Kalkouni R, Iliopoulou S, Rigakos, G, Baka A. 2014. Latrodectus Envenomation in Greece. The Permanente Journal 18(4): e155–e158. ==> HTML|
During the summer period 2011–2012, seven widow spider bites in Greece were reported to the Hellenic Center for Disease Control and Prevention. Widow spiders (in the genus Latrodectus) are found all over the world, including Europe, Asia, Africa, Australia, and the US. Alpha-latrotoxin (main mammalian toxin) causes the toxic effects observed in humans. Victims should receive timely medical care to avoid suffering. Latrodectus bites are very rarely fatal.
All the patients reported having an insect bite 30 minutes to 2 hours before they arrived at the Emergency Department of the local hospital. Severe muscle cramps, weakness, tremor, abdominal pain, and increased levels of creatinine phosphokinase were present in all patients. The Emergency Operation Center of the Hellenic Center for Disease Control and Prevention was informed immediately in all cases. Antivenin was administered to four patients upon the request of their physicians.
All patients recovered fully. It is essential that health care workers recognize early the symptoms and signs of Latrodectus bites to provide the necessary care. The management of mild to moderate Latrodectus envenomations is primarily supportive. Hospitalization and possibly antivenin should be reserved for patients exhibiting serious systemic symptoms or inadequate pain control. The most important thing for all of these patients is early pain relief.
Arrington BD. 2014. The Prevalence and Effect of Wolbachia Infection on the Brown Widow Spider (Latrodectus Geometricus). Master of Science in Biology, Georgia Southern University, Electronic Theses & Dissertations, Paper 1113. 66 pp. ==> Abstract ==> PDF|
Wolbachia was recently identified in the Brown Widow Spider (Latrodectus geometricus). This symbiont has not previously been found in this genus, therefore the consequences on the host's population dynamics are unknown. The frequency of endosymbiont infection can provide insight into the population dynamics of the host as this bacteria is known to alter host life history. In my 1st chapter I determine the prevalence of Wolbachia pipentis infection in the Brown Widow Spider (Latrodectus geometricus) from five locations in the Southeastern United States. Infection frequency differed significantly among sampling locations, ranging from 20% to 92%. These results suggest that the strain is not an obligate symbiont and does not provide a strong fitness benefit to the spider. The observed distribution pattern also suggests recent founder events and possibly limited gene flow among sampled locations as we would expect similar infection frequencies in populations with high gene flow.
Wolbachia is known to alter arthropod life history patterns (e.g., male-killing, feminization, induced parthenogenesis, nutrient acquisition, etc.). As this symbiont has not previously been found in the genus Latrodectus, the consequences on the spider's life history are unknown. In the 2nd chapter, I examine the effects of infection on the spider's reproduction (sex ratio, clutch size, egg size, and egg mass) and juvenile development time. No significant difference in clutch sex ratio, egg number, egg size, egg mass, or development time was found between infected and uninfected females. These results suggest that the strain is not an obligate symbiont nor does it alter the reproductive biology of the spider, as it does in most species. The lack of effect on the host suggests infection is either: i) neutral, and remains in the population by complete maternal transmission or has reached an equilibrium, or ii) affects a trait that was not analyzed in this study.
Bennett KM. 2014. α-Latrotoxin Genes are Highly Divergent Between Species of Widow Spiders (Genus Latrodectus). Thesis, Georgia Southern University, University Honors Program Theses, Student Research Papers. Paper 28. 25 pp. ==> Abstract ==> PDF|
Widow spiders (genus Latrodectus) possess neurotoxic venom that varies in potency among species. α-latrotoxin is the main protein in widow venom that affects vertebrates, including humans. The European black widow, Latrodectus tredecimguttatus, is currently the only species in this genus where the gene for α-latrotoxin has been characterized. The study presented here characterizes the genetic composition of α-latrotoxin from two additional species, the brown widow (L. geometricus) and the southern black widow (L. mactans). Genetic differences among the three species were quantified for α-latrotoxin. Between species genetic divergence in α-latrotoxin was also compared to that of a second gene, cytochrome oxidase I (COI), which is not associated with Latrodectus venom. Functional genetic differences among species were high with amino acid differences ranging from 14% - 58%. Amino acid divergence was approximately 3.7 times greater between species in α-latrotoxin than in COI.
Gburek T. 2014. Plasticity of the red hourglass in female western black widow spiders (Latrodectus hesperus): Urban ecological variation, condition-dependence, and adaptive function. Thesis for the Degree Master of Science, ARIZONA STATE UNIVERSITY. ==> PDF|
Urbanization provides an excellent opportunity to examine the effects of human-induced rapid environmental change (HIREC) on natural ecosystems. Certain species can dominate in urban habitats at the expense of biodiversity. Phenotypic plasticity may be the mechanism by which these 'urban exploiters' flourish in urban areas. Color displays and condition-dependent phenotypes are known to be highly plastic. However, conspicuous color displays are perplexing in that they can be costly to produce and may increase detection by enemies. The Western black widow spider (Latrodectus hesperus) is a superabundant pest species that forms dense aggregations throughout metropolitan Phoenix, Arizona, USA. Adult female L. hesperus display a red hourglass on their abdomen, which is speculated to function as a conspicuous warning signal to enemies. Here, I performed field studies to identify how widow morphology and hourglass color differ between urban and desert subpopulations. I also conducted laboratory experiments to examine the dietary sensitivity of hourglass coloration and to identify its functional role in the contexts of agonism, mating, and predator defense. My field data reveal significant spatial variation across urban and desert subpopulations in ecology and color. Furthermore, hourglass coloration was significantly influenced by environmental factors unique to urban habitats. Desert spiders were found to be smaller and less colorful than urban spiders. Throughout, I observed a positive correlation between body condition and hourglass size. Laboratory diet manipulations empirically confirm the condition-dependence of hourglass size. Additionally, widows with extreme body conditions exhibited condition-dependent coloration. However, hourglass obstruction and enlargement did not produce any effects on the outcome of agonistic encounters, male courtship, or predator deterrence. This work offers important insights into the effects of urbanization on the ecology and coloration of a superabundant pest species. While the function of the hourglass remains undetermined, my findings characterize the black widow's hourglass display as extremely plastic. Plastic responses to novel environmental conditions can modify the targets of natural selection and subsequently influence evolutionary outcomes. Therefore, assuming a heritable component to this plasticity, the response of hourglass plasticity to the abrupt environmental changes in urban habitats may result in the rapid evolution of this phenotype.
Hifumi T, Fujimi S, Yamagishi T, Arai S, Sawabe K, Yamamoto A, Ato M, Shibayama K, Ginnaga A,Kiriu N, Kato H, Koido Y, Inoue J, Kishikawa M, Abe Y, Kawakita K, Hagiike M. and Yasuhiro Kuroda Y. 2014. Clinical characteristics of redback spider bites. Journal of Intensive Care 2: 62. (doi: 10.1186/s40560-014-0062-3) ==> PDF|
Background: Redback spiders (Latrodectus hasselti) (RBSs) are venomous spiders that have recently spread to Asia from Australia. Since the first case report in 1997 (Osaka), RBS bites have been a clinical and administrative issue in Japan; however, the clinical characteristics and effective treatment of RBS bites, particularly outside Australia remains unclear. This study aimed to elucidate the clinical characteristics of RBS bites and to clarify the effectiveness of the administration of antivenom for treatment.
Methods: We performed a retrospective questionnaire survey from January 2009 to December 2013 to determine the following: patient characteristics, effect of antivenom treatment, and outcomes. To clarify the characteristics of patients who develop systemic symptoms, we compared patients with localized symptoms and those with systemic symptoms. We also examined the efficacy and adverse effects in cases administered antivenom.
Results: Over the 5-year study period, 28 patients were identified from 10 hospitals. Of these, 39.3% were male and the median age was 32 years. Bites most commonly occurred on the hand, followed by the forearm. Over 80% of patients developed local pain and erythema, and 35.7% (10 patients) developed systemic symptoms. Baseline characteristics, vital signs, laboratory data, treatment-related factors, and outcome were not significantly different between the localized and systemic symptoms groups. Six patients with systemic symptoms received antivenom, of whom four experienced symptom relief following antivenom administration. Premedication with an antihistamine or epinephrine to prevent the adverse effects of antivenom was administered in four patients, which resulted in no anaphylaxis. One out of two patients who did not receive premedication developed a mild allergic reaction after antivenom administration that subsided without treatment.
Conclusions: Approximately one third of cases developed systemic symptoms, and antivenom was administered effectively and safely in severe cases. Further research is required to identify clinically applicable indications for antivenom use.
Keywords: Redback spider, Antivenom, Systemic symptom
東岡礼治. 2014. 行政の立場から外来生物法の今後を考える. 雑草研究 59(2): 93-99. ==> PDF|
...外来生物法に基づいて指定された特定外来生物のリスト...ゴケグモ属のうち 4 種（ハイイロゴケグモ， セアカゴケグモ ，クロゴケグモ，ジュウサンボシゴケグモ）...
MacLeod EC, Andrade MCB. 2014. Strong, convergent male mate choice along two preference axes in field populations of black widow spiders. Animal Behaviour 89: 163–169. ==> HTML & PDF|
Strong male mate preferences have been documented in species with otherwise conventional sex roles in the laboratory, and across taxa, male preferences generally focus on indicators of female fecundity and sperm competition risk. However, the few field studies of male choice rarely show equally strong effects. This suggests that costs of choice in nature may make the expression of preferences unlikely, or that interacting assessment cues may lead to unpredictable and variable outcomes in the wild. Field studies are therefore critical for testing whether or not male mate choice is sufficiently strong to exert sexual selection on females. Here we examine male choice in nature in response to two experimentally manipulated cues of female reproductive value. We recorded the attraction of male black widow spiders, Latrodectus hesperus, to females in a field enclosure and in a unconstrained natural setting. Stimulus females varied in two ways: sperm competition risk (low–unmated; high–mated) and fecundity (high–fed; low–unfed). Females and their silk were caged to prevent behavioural interactions while allowing the spread of airborne pheromones that attract males. Males in both experiments showed strong, nearly unanimous choice for unmated, well-fed females. In field enclosures, 80% of males made this choice, and wild males made the same choice in 94% of trials. We conclude that male choice in L. hesperus is mediated by detection of airborne pheromones, is strong and consistent despite natural costs of mate searching, and is not affected by natural interactions between (sometimes conflicting) cues of female reproductive value. Thus, universal mate choice may exist among males in nature. We propose general features of systems in which this may be likely and discuss implications for the study of sexual selection on females under conventional sex roles.
Modanu M, Li LDX, Said H, Rathitharan N, Andradea MCB. 2014. Sibling cannibalism in a web-building spider: Effects of density and shared environment. Behavioural Processes 106: 12–16. ==> Abstract 【PDF Contentsﾘｽﾄからdownload可】|
Sibling cannibalism occurs across diverse taxa and can affect population size and structure, as well as the fitness of parents and the cannibal, via density effects and variation in individual propensity to cannibalize. We examined these effects on sibling cannibalism in juveniles of a web-building spider (Latrodectus hasselti, Australian redbacks). Adult redbacks are solitary, but juveniles live in clusters of variable density for a week after hatching. We confined newly hatched siblings from a singly-mated female to a low or high density treatment in a split-clutch design, then left spiderlings unfed for a week. Our results showed no effect of density on overall cannibalism levels, but a strong correlation between cannibalism counts from the same maternal lines across densities. Unlike web-bound sit-and-wait predators, wandering spiders that are active hunters have been shown to experience density-dependent cannibalism. In contrast, we suggest sibling cannibalism in web-building spiders may be density independent because early cohabitation on the web selects for elevated tolerance of conspecifics. We conclude that, rather than being linked to density, cannibalism of siblings in these species may be controlled more strongly by variation in individual propensity to cannibalize.
Pravalikha GB, Srinivasulu C. 2014. First report of black widow spider Latrodectus hasselti Thorell, 1870, from Telangana, India. Species (The International Daily Journal for Species) 10(23), September 10, 2014: 19-23. ==> PDF|
Latrodectus hasselti (Thorell, 1870), the black widow spider has been reported from many parts of India but was hitherto unknown from Telangana state, India. In this paper we give the first report of the black widow spider with notes on complete description of the external characters, their morphometry and the internalgenitalia of the specimen.
清水裕行，金沢至，西川喜朗. 2014. 日本のゴケグモ類5種の分布状況とセアカゴケグモの分散方法に関する考察. Bulletin of the Osaka Museum of Natural History (大阪市立自然史博物館) 68: 41-51. ==> PDF|
Smith VR, Vink CJ, Paterson AM. 2014. Carbon dioxide versus cold exposure for immobilising live redback spiders Latrodectus hasseltii Thorell, 1870 (Araneae: Theridiidae). New Zealand Entomologist DOI: 10.1080/00779962.2014.884533. ==> Abstract 【Full Text 有料】|
Studying live spiders often involves non-lethally immobilising them. The use of CO2 and refrigeration were investigated, both alone and combined, as methods for immobilising redback spiders (Latrodectus hasseltii). Specimens of L. hasseltii were exposed separately to CO2 and cold temperatures (4.2°C) for time intervals ranging from 5 to 12 s and 4 to 45 min, respectively. Subsequent behaviour exhibited by the spiders was described as either positive or negative: if handling and removal from the container were possible without risking escape or injury this was described as a positive reaction. Conversely, if the spider was too active to be handled the reaction was counted as negative. Two minute CO2 exposure had a significant positive effect on spider response; refrigeration and combining the two treatments did not produce significant effects. Carbon dioxide was the most successful method of immobilising spiders; however, we caution using it for endangered species until further research has been conducted into long-term effects.
Zamani A, Mirshamsi O, Savoji A, Shahi M. 2014. Contribution to the distribution of spiders with significant medical importance (Araneae: Loxosceles and Latrodectus) in Iran, with a new record for the country. Iranian Journal of Animal Biosysytematics 10(1): 57-66. ==> Abstract ==> PDF|
A faunistic review is given on the Iranian medically important spiders of two genera Loxosceles and Latrodectus. Latrodectus cinctus Blackwall, 1865 is reported for the first time from Iran (and for the second time from Asia) and is replaced with the previous erroneous reports of L. hasseltii Thorell, 1870. The following species are reported for the first time from the listed provinces: Loxosceles rufescens (Dufour, 1820) (Fars and Hormozgan), L. dahli Levi, 1959 (Hormozgan), L. pallidus O.P.-Cambridge, 1872 (Alborz and Semnan) and L. tredecimguttatus (Rossi, 1790) (Alborz, Qom, Semnan and Tehran).
|2013||上村清. 2013. セアカゴケグモの耐寒性と毒作用. 環境管理技術(環境管理技術研究会) 31(5), 184-194. ==> information only|
|2013||金沢至. 2013. セアカゴケグモなどのゴケグモ類の現状と問題. 環境管理技術(環境管理技術研究会) 31(6): 249-256. ==> information only|
Kasumovic MM. 2013. The multidimensional consequences of the juvenile environment: towards an integrative view of the adult phenotype. ANIMAL BEHAVIOUR 85(5): 1049-1059. ==> HTML|
Early juvenile environments influence trait expression in complex and often nonintuitive ways. Although the breadth of these effects is well recognized, researchers generally focus on the effect of single ecological triggers (such as resource availability, latitude or predator presence) on traits within a single dimension (e.g. morphological, behavioural or physiological phenotypes). This approach has yielded a wealth of knowledge about environmental conditions that trigger different plastic allocation strategies and reaction norms of a number of traits. However, it tells us little about the way in which early life conditions influence resource allocation, yielding differentially integrated adult phenotypes. Here, I argue that we must begin to understand how complex environments shape the conditional development and expression of suites of traits to produce complex, adaptive phenotypes. I begin by examining the importance of the juvenile environment when attempting to understand phenotypic expression at later life history stages. I describe how different types of plasticity affect relationships between traits, and I provide four case studies that illustrate the influence of plasticity on trait integration, which strongly suggests that evolution of norms of reaction must be considered if we are to understand the evolution of integrated phenotypes. I next highlight the importance of understanding the physiological and genetic underpinnings of this plasticity because such poorly understood aspects of the phenotype regulate developmental pathways that determine phenotypic expression. I conclude with suggestions as to how future research can begin to accommodate multidimensional approaches, and in doing so, further our understanding of an integrated phenotype concept.
|2013||久米井綾，吉田康彦，今西久幹. 2011. 速報的小論文 セアカゴケグモ 咬症の1例 (A case of red back spider envenomation). 日本皮膚科学会雑誌 121(9): 1881-1884. ==> information only|
Noordijk J, Vos J, Schoelitsz B. 2013. Risk of black widow and related spider species. Risicobeoordeling van zwarte weduwen en verwante spinnensoorten. 30 pp. ==> book information|
... hasseltii; Latrodectus hesperus; Latrodectus mactans. Descriptor: invasive species; Ministries of Agriculture; risk assessment; venomous animals. Identifier: black widow spider; Dutch Ministry of Agriculture, Nature & Food Quality; invasive organisms; invasives; Latrodectus hasselti ...
|2013||冨永修. 2013. 行政の内側から見たセアカゴケグモ騒動. 環境管理技術(環境管理技術研究会) 31(5): 176-183. ==> information only|
櫻庭洋，松田洋，明石和大，石井照久. 2013. 中学校または高等学校での津波教育・里山教育・生物実験単元教育に関する一考察. 秋田大学教育文化学部研究紀要 教育科学 68: 51-64. ==> Abstract ==> PDF|
Some teaching programs in junior high school and high school were discussed. “Tsunami” subject in teaching is necessary and difficult in junior high school and high school especially after 3.11 in 2011 in Japan. We propose one of model programs of ‘‘Tsunami” subject in teaching. Also, we analyze and discuss both “Satoyama” and “Biological experiments” subjects in teaching along with official textbooks in Japan in high school biological education.
|2013||小林睦生, 沢辺京子. 2013. 感染症の話 78 セアカゴケグモ (Latrodectus hasseltii) とは. IDWR感染症の話，国立感染症研究所ホームページ（2013年2月1日） ==> PDF|
MacLeod, Emily. 2013. New Insights into the Evolutionary Mantenance of Male Mate Choice Behaviour using the Western Black Widow Spider, Latrodectus hesperus. Doctoral thesis, Ecology and Evolutionary Biology, University of Toronto, 221 pp. ==> PDF|
Mate choice among males is relatively understudied, despite recent evidence supporting its ubiquity. Theory predicts male mate choice in response to variation in female quality, and male mating strategies that limit polygyny. However empirical research investigating these connections, particularly under natural conditions, is generally lacking. Using the Western black widow spider, Latrodectus hesperus, I investigated male mate choice, male investment, and the advantage of mating with females that differ in their potential to deliver fitness benefits to males via higher fecundity and/or reduced risk of sperm competition. Males were found to be preferentially attracted to larger, high-diet virgin females over females that were smaller due to a lower diet, or having been previously mated, or both. Through a three-year field study on females I found that males likely benefit from selectivity, as smaller, low-diet females often failed to deposit any egg sacs throughout the breeding season, likely due to their shortened web-site tenure and/or lack of bodily resources. I investigated the costs and benefits to male genital breakage in L. hesperus, a strategy typically assumed to result in male sterility while providing paternity protection. I found that genital mutilation in L. hesperus did not cause sterility and that males were capable of inseminating multiple females, likely because of the comparatively low amount of genital damage and the likelihood of the efficient placement of genital fragments. Evidence from double mating trials supported the efficacy of broken genital fragments as plugs, but first male sperm precedence was often maintained in cases where male genital breakage failed or fragments were positioned incorrectly, which occurred frequently. Together, these laboratory and field experiments contribute to a more complete view of mate choice.
|2013||Metcalfe DC, Ridgeway PA. 2013. A case of web entanglement and apparent predation of the skink Lampropholis delicata (De Vis, 1888) (Sauria: Scincidae: Lygosominae) by the red-back spider Latrodectus hasseltii Thorell, 1870 (Aranea: Araneomorpha: Theridiidae) in an autochthonous mesic habitat in coastal southeast Australia. Herpetology Notes 6: 375-377. ==> PDF|
Modanu M, Michalik P and Andrade MCB. 2013. Mating system does not predict permanent sperm depletion in black widow spiders. Evolution & Development 15(3): 205–212. (DOI: 10.1111/ede.12034) ==> HTML ==> PDF|
Variation in sperm production is strongly influenced by mating system across taxa. Recent work in spiders suggests that males of some species show termination of spermatogenesis before their adult molt and thus an inability to produce sperm after maturation. This permanent sperm depletion (PSD) has been hypothesized to co-occur with monogyny, genital mutilation, or sexual cannibalism because the maintenance of continual sperm supplies is not necessary for species where males can expect only one mating opportunity. Here we test this hypothesis in two congeners exhibiting genital mutilation: the sexually cannibalistic, monogynous Australian redback spider Latrodectus hasselti and the polygynous Western black widow Latrodectus hesperus. We report that PSD does not occur in adult males of either species, and show that males transfer sperm into their copulatory organs multiple times as adults. These data suggest evolutionary links between mating system and investment in sperm production may be more complex than currently appreciated.
|2013||吉田政弘. 2013. 危険生物 セアカゴケグモ について (特集 身の回りの特定外来生物). 生活と環境 58(3): 14-19. ==> information only|
|2013||[講演要旨] 吉田政弘. 2013. 最近の外来生物, 特にセアカゴケグモおよびアルゼンチンアリの現状について. ペストロジー 28(1): 37-38. (第28回日本ペストロジー学会大会・特別講演) ==> information→PDF|
Abdul-Rassoul MS, Al-JalelyBH, Al-Nuaimi KT and Al-Ani Lk. 2012. First record of red-back spider Latrodectus scelio Thorell, 1870 (Araeae: Theridiidae) in Baghdad, Iraq. Bull. Iraq nat. Hist. Mus. 12(2): 1-5. ==> PDF|
Two females of the red-back spider, Latrodectus scelio Thorell, 1870 were first recorded in Iraq, short description with figure was provided.
|2012||Bibb CS, Buss LJ. 2012?. Widow spider parasitoids Philolema latrodecti (Fullaway)(Insecta: Hymenoptera: Eurytomidae) and Baeus latrodecti Dozier (Insecta: Hymenoptera: Platygastridae). IFAS Extention, University of Florida [Web Page only?] ==> PDF 寄生蜂の写真あり|
Hippargi RV, Bolde PM, Manthen SV, Shaikh AR. 2012. Ecology of venomous spider Latrodectus hasselti Thorell, 1870 (Araneae: Theridiidae) from Solapur and Osmanabad District, Maharashtra. Indian Journal of Arachnology 1(1): 169-174. ==> PDF|
Spiders belonging to genus Latrodectus are well known as spiders of medical importance, as they present a real envenomation threat to humans leading to mild and sometimes severe pathological manifestations referred as latrodectism. Primary goals of this study were to gather baseline data on the distribution, population, behavior and breeding biology of Latrodectus hasselti from grassland ecosystem of Solapur and dry deciduous forest from Yedshi Ramling Sanctuary, Osmanabad. Marked seasonal variation was observed in the abundance, distribution and breeding with higher preference for grassland ecosystem. Preliminary observation on the breeding biology was carried out on a female reared in vivarium. Such surveys are vital for conservation of these creatures.
Mason A, Elias D and De Luca P. 2012. Complex signals: what do spiders have to say?. Front. Behav. Neurosci. Conference Abstract: Tenth International Congress of Neuroethology. (doi: 10.3389/conf.fnbeh.2012.27.00022) ==> Abstract only|
Courtship signals vary in complexity, but are often more elaborate than long-range advertisement signals, having multiple signal components sometimes produced in different sensory modalities. The interaction between components within complex signals and the contribution of individual components to overall signal function are poorly understood. I will compare courtship displays in three spider groups that span a range of complexity in signal structure: jumping spiders; wolf spiders; and widow spiders. Jumping spiders of the genus Habronattus show highly elaborate male courtship displays that comprise multiple signal elements in at least two sensory modalities (visual and vibratory). In this group, prolonged, multimodal courtship displays are highly structured (with a regular, species-specific progression of signal elements throughout the display), and show a pattern of diversification across the genus that is consistent with selection for suites of multimodal traits driven by female preferences for displays of higher complexity. In contrast, Australian redback spiders (Latrodectus hasselti) prolonged male courtship displays are relatively unstructured. Evidence in this system suggests that courtship signals, consisting primarily of web-borne vibration, are a simple broadcast of vibrational energy that is integrated by females to arrive at a mate-acceptance threshold. Wolf spiders (genus Schizocosa) represent an intermediate between these two. Males produce complex vibrational displays comprising multiple elements that are produced by independent mechanisms and that are correlated with distinct aspects of male quality (developmental history vs current condition). I speculate that these differences in complexity and information content of male signals critically depend on effects of variable substrates on signal transmission and constraints of female sensory capacities (largely a function of hunting ecology).
Krogmann L, Austin AD. 2012. Systematics of Australian Agenioideus Ashmead (Hymenoptera: Pompilidae) with the first record of a spider wasp parasitizing Latrodectus hasselti Thorell (redback spider). Australian Journal of Entomology 51(3): 166–174. ==> Abstract ==>PDF|
The Australian members of the spider wasp genus Agenioideus are revised, and its two constituent species, Agenioideus expulsus Turner and A. nigricornis (Fabricius), are redescribed. A third species, Agenioideus ultimus (Turner), is transferred to Spuridiophorus Arnold, a genus that is newly recorded here from the Australian continent. Diagnoses and criteria to facilitate the identification of the two genera are provided, along with information on the distribution and host biology of Agenioideus species. The first records of a pompilid utilising Latrodectus hasselti Thorell (redback spider) as a host at multiple locations across southern Australia are presented, along with a brief synopsis of insect parasitoids and predators of L. hasselti in Australia.
Scott C, Vibert S, Gries G. 2012. Evidence that web reduction by western black widow males functions in sexual communication. The Canadian Entomologist 144(05): 672-678 (DOI:10.4039/tce.2012.56) ==> Abstract [No free PDF?]|
A well-accepted function of courtship in sexually dimorphic and cannibalistic spiders is suppression of female predatory responses. We quantitatively analysed courtship in the western black widow, Latrodectus hesperus Chamberlin and Ivie (Araneae: Theridiidae), to determine the behavioural elements of the males’ courtship that are correlated with mating success and/or the females’ responses. The 58% of males that engaged in web reduction elicited fewer aggressive responses from females and induced female quiescence more quickly than did males not exhibiting web reduction behaviour. Our data suggest that web reduction by male L. hesperus functions in sexual communication, a context not previously explored.
Sirvid PJ, Vink CJ, Wakelin MD, Fitzgeralda BM, Hitchmoughe RA & Stringere IAN. 2012. The conservation status of New Zealand Araneae. New Zealand Entomologist 35(2): 85-90. ==> Abstract ==>PDF|
We classify three New Zealand spiders (Araneae) as Threatened: Maloides cavernicola (Amaurobiidae) and Zealoctenus cardronaensis (Miturgidae) as Nationally Critical; and Maniho centralis (Amphinectidae) as Nationally Endangered. There are 155 At Risk taxa: Latrodectus katipo (Theridiidae) is Declining, seven taxa are R elict and a further 147 taxa are Naturally Uncommon. We classify 527 taxa as D ata D eficient. Since the last listing of Threatened spiders the number of species categorised as Threatened and At Risk has increased slightly (one and 28 taxa respectively) whereas the number categorised as Data Deficient has been reduced by 309 taxa. Not Threatened taxa have increased more than twofold to 403 taxa. Some biological factors that may affect the threat status of New Zealand spiders are briefly discussed.
Stoltz JA , Andrade MCB, Kasumovic MM. 2012. Developmental plasticity in metabolic rates reinforces morphological plasticity in response to social cues of sexual selection. Journal of Insect Physiology 58(7): 985–990 (doi:10.1016/j.jinsphys.2012.05.002) ==> Abstract ==> PDF|
Developmental plasticity allows individuals to match their phenotype to the competitive environment they are most likely to encounter. Although there are numerous studies that demonstrate adaptive shifts in life-history and metric traits, we still have a poor understanding of whether internal physiological processes demonstrate plasticity and whether this plasticity supports life-history and metric traits. Here we use the Australian redback spider (Latrodectus hasselti), a species that demonstrates adaptive developmental shifts in response to the availability of females and the density of males, to examine the relationship between the routine metabolic rate (RMR) and the expression of size, body-condition and development rate. We reared immature males in three diet treatments, and in social environments that varied the presence/absence of females and the density of males and measured their RMR, weight, size and developmental rate at maturity. We show that although RMR decreased with decreasing resource abundance, RMR was positively correlated with the density of rivals. Moreover, RMR was not correlated with size or body-condition at maturity. Our results demonstrate that plasticity in the RMR supports plasticity in metric and life-history traits to create an integrated phenotype that matches the competitive environment.
|2012||辻英名．2012. 書評：清水裕行・金沢至・西川嘉朗著, 毒グモ騒動の真実 セアカゴケグモ の侵入と拡散 (全国農村教育協会, 2012年7月発行, A5版 196頁). ペストロジー 27(2): 67 ==> information→PDF|
Vetter RS, Vincent LS, Itnyre AA, Clarke DE, Reinker KI, Danielsen DWR, Robinson LJ, Kabashima JN, and Rust MK. 2012. Predators and parasitoids of egg sacs of the widow spiders, Latrodectus geometricus and Latrodectus hesperus (Araneae: Theridiidae) in southern California. Journal of Arachnology 40(2):209-214. (doi: 10.1636/Hi11-93.1) ==> Abstract 【本文，このサイトからは有料】|
The brown widow spider, Latrodectus geometricus C. L. Koch 1841, is non-native to North America and has experienced an explosive range expansion in the first decade of the 21st century. Previously restricted to peninsular Florida, it is now well established in the southeastern United States and southern California. In southern California, brown widow spiders have become ubiquitous around urban homes and are well known to the general public because of their high numbers and distinctive spiked egg sacs. Several insects attack egg sacs of the native western black widow, L. hesperus Chamberlin & Ivie 1935, as either parasitoids or egg predators. We investigated whether and to what degree these insects would attack brown widow egg sacs. We dissected 3,739 brown widow egg sacs finding evidence of the chloropid fly, Pseudogaurax signatus (Loew 1876) in 2.0% and wasp parasitoids in 0.4% of the sacs. For comparison, we also dissected 263 western black widow egg sacs with P. signatus showing a higher level of predation (6.1%). Other brown widow sac inhabitants included larvae and adults of dermestid beetles, psocids, and lepidopterans, which are probably scavengers or incidental occupants. The overall impact of the recorded predators and parasitoids is too low to explore the possibility of a biological control program. Additionally, due to the relatively low number of predators/parasitoids in brown widow egg sacs and the entanglement of small arthropods on the outer surface, we speculate that the spiked egg sac surface might serve as an effective barrier to most predators and parasitoids.
Jäger P, Gromov AV. 2011. First records of Latrodectus dahli Levi, 1959 from Morocco, Turkey, Turkmenistan and the United Arab Emirates. Arachnology (Bulletin of the British Arachnological Society) 15(6): 188-192. ==> PDF|
Latrodectus dahli Levi, 1959 is recorded from Morocco, Turkey, Turkmenistan and the United Arab Emirates for the first time. New records are given from Uzbekistan and Tajikistan. The morphology of the female copulatory organ is illustrated. The single female from Morocco represents the westernmost record of this species and is 3700 km distant from the previously known distribution range (Middle East to Central Asia). A map including all known records is provided.
Jerhot E, Stoltz JA, Andrade MCB and Schulz S. 2010. Acylierte Serinderivate: eine einzigartige Klasse von Arthropoden‐Pheromonen der Australischen Rotrückenspinne Latrodectus hasselti. Angewandte Chemie 122(11): 2081–2084 (DOI: 10.1002/ange.200906312) ==> Abstract[ドイツ語] ==> PDF[ドイツ語]|
Unwiderstehlich: Aminosäurederivate werden sehr selten von Arthropoden als Pheromone genutzt. Die zu den Witwen gehörende Spinne Latrodectus hasselti (siehe Bild) nutzt eine einzigartige Verbindung (siehe Strukturformel), um ihre Männchen anzulocken. Die Molekülkonfiguration spielt eine wichtige Rolle beim chemischen Kommunikationssystem dieser Spinne.
Johnson JC, Trubl P, Blackmore V, Miles L. 2011. Male black widows court well-fed females more than starved females: silken cues indicate sexual cannibalism risk. Animal Behaviour 82(2): 383–390. ==> HTML ==> PDF|
Male mate choice is predicted to evolve as male investment in mating increases. Thus, taxa in which males pay a high cost for mating offer researchers an ideal system to test traditional sex roles. Males courting potentially sexually cannibalistic females may be under strong selection to bias their courtship efforts away from hungry females that may be more likely to attack. Here we tested the prediction that web-based chemotactile cues of recent female foraging success influence male courtship in the black widow spider, Latrodectus hesperus. In addition, we tested the underlying assumption that previous female foraging success reduces precopulatory sexually cannibalistic attacks. We found that males courted well-fed females significantly more than they did starved females, and that this bias was maintained in the absence of the female when males encountered only (1) cues from female webs and (2) cues from female silk after web architecture had been eliminated. A nonsignificant courtship bias in favour of well-fed females was also evident when these females were transplanted to the webs of starved females. Male courtship biases in favour of well-fed females appear adaptive, as starved females were significantly more likely to attack males before mating. We conclude by noting that sexual cannibalism offers a model system wherein the exploitation of cues of predation risk have unique implications such as the effects on male courtship preferences seen here.
|2011||Kananbala A, Manoj K, Bhubaneshwari M, Binarani A, Siliwal M. 2012. The first report of the widow spider Latrodectus elegans (Araneae: Theridiidae) from India. Journal of Threatened Taxa 4(7): 2718–2722. ==> PDF|
Neumann R, Schneider JM. 2011. Frequent failure of male monopolization strategies as a cost of female choice in the black widow spider Latrodectus tredecimguttatus. Ethology 117(12): 1057–1066. (DOI: 10.1111/j.1439-0310.2011.01971.x) ==> HTML ==> PDF|
In many mating systems, males strive for securing paternity through monopolizing females. As male monopolization attempts often contradict female interests, this conflict may fuel an evolutionary arms race. In the widow spider genus Latrodectus, females are commonly polyandrous, whereas males are monogynous, hence restricted to mate with a single female, making paternity protection particularly important. Potential mating plugs (specialized embolus sclerites of male copulatory organs) have been discovered in the complex female genital tracts of several Latrodectus species. In this study, we investigated mating strategies in the Mediterranean black widow spider Latrodectus tredecimguttatus and tested the adaptive value of female attacks against male monopolization efforts. In a double mating experiment, we manipulated the number of insertions (=copulations) for first and second males to assess female behaviour and male embolus sclerite placement success. Our results indicate that first males′ embolus sclerites inside the females′ sperm stores physically block sclerites of subsequent males. While female attacks did not affect the deposition of potential mating plugs, they significantly reduced copulation duration. Irrespective of female aggression, male sclerite placement failure occurred frequently, but large males were more successful than smaller competitors. We suggest that the complex genital morphology in both sexes may have co-evolved antagonistically and female morphology could serve to favour large males for fertilization.
Roy HE, Roy DB, Roques A. 2011. Inventory of terrestrial alien arthropod predators and parasites established in Europe. BioControl 56(4): 477-504. (DOI:10.1007/s10526-011-9355-9) ==> Abstract & PDF ==> HTML|
There are currently 1590 terrestrial arthropod species identified as alien to Europe. Of these, 513 are predators or parasites. The largest group is the insects (409 species), followed by spiders (47 species), myriapods (34 species) and mites (23 species). The species within these alien groupings are extremely diverse, as highlighted by the large number of families represented (115 families). The majority (66.1%) of alien arthropod predator and parasite species arrived unintentionally, but at least 174 (33.9%) have been introduced intentionally, mainly for biological control purposes. Assessment of the major invasion pathways is difficult due to the lack of comprehensive information but it is likely that the majority of predatory or parasitic alien arthropods arrive through leading-edge dispersal or as contaminants and stowaways. The number of new species arriving in Europe has progressively increased since 1500, with the increase in global trade over the last century accelerating this rate of increase. Only a small number of alien predatory and parasitic arthropods in Europe have been shown to cause either an ecological or economical impact, yet knowledge is severely limited by a paucity of data.
Salomon M. 2011. The natural diet of a polyphagous predator, Latrodectus hesperus (Araneae: Theridiidae), over one year. Journal of Arachnology 39(1):154-160. ==> PDF 【本文，このサイトからは有料】|
The natural diets of many terrestrial predators such as spiders have yet to be investigated. In this study, I analyzed the diet of a web-building spider, Latrodectus hesperus Chamberlin & Ivie (1935), over one year in a natural habitat of coastal British Columbia, Canada. This is the first study to document the natural diet of L. hesperus over several months. I identified and measured 1599 prey items collected from L. hesperus webs and web sites between January and December. Spiders fed on ground-active prey from eight different orders of arthropods. Coleoptera and Hymenoptera were the predominant prey of L. hesperus in this habitat, combinely accounting for >85% of the total prey catches and biomass. The other prey orders included, in order of abundance, Isopoda, Araneae, Dermaptera, Orthoptera, Lepidoptera and Diptera. Spiders captured prey mostly between May and October, when females oviposit, juveniles grow, and prey are most active. These results show that L. hesperus is a polyphagous predator that feeds primarily on prey from two orders of insects.
Shahi M, Hosseini A, Shemshad K, and Rafinejad J. 2011. The occurrence of red-back spider Latrodectus hasselti(Araneae: Theridiidae) in Bandar Abbas, southern Part of Iran. Iran J Arthropod Borne Dis. 5(1): 63–68. ==> HTML ==> PDF
Background: Due to importance and fatal affect of Red-back spiders, Latrodectus hasselti, a faunistic survey for presence of this spider in Bandar Abbas has been conducted. This animal is considerably the most medically importance spiders all over the world.
Methods: Live adult spider specimens were collected from Bandar Abbas town using hand catch conventional method and transferred to the laboratory throughout the summer of 2008. They were identified based on morphological characteristics and taxonomic keys and confirmed by some external experts.
Results: Results showed the occurrence of the red-back spider, L. hasselti from Bandar Abbas, southern port of Iran. Two female specimens were found. The spider had specific morphological characters including black color with an obvious orange to red longitudinal strip on its upper parts of abdomen.
Conclusion: Although the specimens were collected from south of the country, however since the region is an important harbor and port and goods come form different parts of world we assume the possibility of arrival from its origin and native breeding sites of the world. Therefore further investigation is needed to clarify the presence of this species in different parts of Iran.
Stoltz, Jeffrey Allan. 2011. Dynamics underlying interacting mechanisms of sexual selection. Doctoral thesis, Ecology and Evolutionary Biology, University of Toronto, 219 pp. ==> PDF|
Sexual selection drives the evolution of male morphology, life history, physiology, and behaviour across taxa. Here I examine the mechanisms of sexual selection that arise at various stages in mating interactions to identify congruence or conflict between the traits selected by choice and competition. I first examine plasticity of developing male Australian redback spiders (Latrodectus hasselti) and show that male metabolic rates vary adaptively to facilitate the scramble to reach virgins. Next, I show that females cease sex pheromone production after mating and re-advertise receptivity later in their reproductive season effectively creating two windows in which males may compete. I show that females discriminate against males that do not meet a threshold courtship duration suggesting that courtship is the trait selected through choice. However, male-male competition leads to reductions in courtship effort provided to females. During the first window paternity is split equally if rival males mate in quick succession with a virgin female. However, if the second mating is delayed, there is a strong bias in the paternity of the second male. A delay in the second mating is beneficial to females as it reduces longevity costs of polyandry. However, delays in the initial mating decrease female longevity, likely because of elevated metabolic rates of virgins. My research shows that the trait favoured by female choice is in opposition to selection via male-male competition. Females’ sex pheromone production yields windows during which mating will optimize female, but not male, fitness. Studies that isolate the mechanisms of sexual selection are valuable in that they can identify the traits under selection. However, my research shows that considering these processes in isolation can lead to incorrect inferences about the net effect of sexual selection.
Vink CJ, Derraik JGB, Phillips CB, Sirvid PJ. 2011. The invasive Australian redback spider, Latrodectus hasseltii Thorell 1870 (Araneae: Theridiidae): current and potential distributions, and likely impacts. Biological invasions 13(4): 1003-1019 (DOI:10.1007/s10530-010-9885-6) ==> Abstract & PDF|
Populations of the Australian redback spider, Latrodectus hasseltii Thorell 1870, were first recorded in New Zealand in the early 1980s and in Osaka, Japan in 1995. Reliable records suggest that naturalised populations of L. hasseltii in New Zealand are present only in Central Otago and New Plymouth. In Central Otago, L. hasseltii feeds on endangered invertebrates, such as Prodontria modesta (Broun 1909). Latrodectus hasseltii is also a hazard to the New Zealand endemic L. katipo through interbreeding and competitive displacement. CLIMEXTM was used to model the potential global distribution of L. hasseltii based on current climate, and using ArcGIS® 9.2, areas of suitable climate in New Zealand were overlaid with favourable habitats to identify areas most suitable for L. hasseltii establishment. In addition, shelter that urban areas offer L. hasseltii were modelled in CLIMEX and incorporated into ArcGIS to produce maps indicating cities and built up areas where the species could establish. The presence of L. hasseltii in New Zealand and Japan, and its possible spread to other areas, is of human health significance, and the species may also impact on native biodiversity.
Araujo D, Maia UM, Brescovit AD. 2010. The first cytogenetic characterization of the poisonous black widow spider Latrodectus gr. curacaviensis; from Brazil, with chromosomal review of the family Theridiidae (Arachnida, Araneae). Micron 41(2): 165–168. ==> Abstract 【本文，このサイトからは有料】|
In this paper we present, for the first time, cytogenetical data on Latrodectus gr. curacaviensis (Theridiidae) from Brazil, as well as the first data on meiosis and sex chromosome system of this genus. Testes were submitted to colchicine, hypotonic, and fixation treatment, and chromosomal preparations were stained with Giemsa solution. The analysis showed 2n = 26 telo/acrocentric chromosomes in spermatogonial metaphases. Metaphase I exhibited 12 autosomal bivalents and two sex chromosome univalents (12II + X1X2). All bivalents revealed one terminal chiasma. Metaphases II confirmed the sex chromosome system, showing 12 autosomes or 12 autosomes plus two X chromosomes, respectively. Male karyotype prevailing in theridiids is formed by 2n = 22 chromosomes, including sex chromosome system X1X2 in all species. The Latrodectus species of the geometricus clade analyzed until now showed smaller diploid number (2n♀ = 16 and 2n♀ = 18) than the species of the mactans clade (2n♀ = 24 and 2n♀ = 26). Thus, according to the chromosome number, the examined Latrodectus species seems to be related to the mactans clade.
Costall JA, Death RG. 2010. Population monitoring of the endangered New Zealand spider, Latrodectus katipo, with artificial cover objects. New Zealand Journal of Ecology 34(2): 253-258. (図表なし？) ==> PDF|
The endangered New Zealand widow spider, Latrodectus katipo, is believed to have undergone marked population decline over the last 30 years, but as monitoring methods are time- and labour-intensive, and require observers to have a high level of experience, the current status of many populations is unknown. We investigated the use of artificial cover objects (ACOs) as an alternative monitoring tool for L. katipo at three sites at Himatangi Beach, Manawatu, New Zealand, from late 2004 through to mid-2005. Occupancy rates of the ACOs were compared to population densities obtained from habitat searches, to assess their efficacy as a monitoring tool. Numbers of the introduced spider, Steatoda capensis，which may be a competitor of L. katipo, were also recorded during habitat searches. ACOs were reliable monitoring tools, with occupancy rates higher at the site with the highest L. katipo population density. Latrodectus katipo populations were found to have highly female biased sex-ratios, with a longer breeding season at Himatangi than reported previously at other sites. Steatoda capensis exists at much higher population densities than L. katipo at Himatangi. However，fluctuations in the populations of the two species appear to be unrelated. ACOs could be used as a non-destructive monitoring tool for many other invertebrate species.
Jerhot E, Stoltz JA, Andrade MCB and Schulz S. 2010. Acylated serine derivatives: a unique class of arthropod pheromones of the Australian redback spider, Latrodectus hasselti. Angewandte Chemie International Edition 49(11): 2037–2040. (DOI: 10.1002/anie.200906312) ==>HTML ==>PDF|
Irresistible: Amino acid derivatives are very rarely used as pheromones by arthropods. The widow spider Latrodectus hasselti (see picture) uses a unique compound (see formula) to lure its males. The molecular configuration plays an important role in this unique chemical communication system.
Kenis M, Branco M. 2010. Impact of alien terrestrial arthropods in Europe. Chapter 5. BioRisk 4: 51-71. ==> Abstract ==> PDF|
This chapter reviews the effects of alien terrestrial arthropods on the economy, society and environment in Europe. Many alien insect and mite species cause serious socio-economic hazards as pests of agriculture, horticulture, stored products and forestry. They may also affect human or animal health. Interestingly, there is relatively little information available on the exact yield and financial losses due to alien agricultural and forestry pests in Europe, particularly at continental scale. Several alien species may have a positive impact on the economy, for example parasitoids and predators introduced for the biological control of important pests. Invasive alien arthropods can also cause environmental hazards. They may affect native biodiversity through various mechanisms, including herbivory, predation, parasitism, competition for resource and space, or as vectors of diseases. They can also affect ecosystem services and processes through cascading effects. However, these ecological impacts are poorly studied, particularly in Europe, where only a handful cases have been reported.
Modanu, Marija. 2010. Compensatory Responses to Copulatory Organ Damage in the Western Black Widow. Doctoral thesis, Ecology and Evolutionary Biology, University of Toronto, 221 pp. ==> PDF|
Experimental alterations of morphological traits during development can reveal life history tactics and resource allocation patterns. I examined effects of amputation of a structure directly involved with mating compared to one that is less associated with fitness. I amputated one of the paired external copulatory organs (palps) of juvenile male black widow spiders Latrodectus hesperus), and compared changes in life history traits and fitness to males with amputated legs and controls. I show that palps are more likely to be regenerated than legs, smaller juveniles are more likely to regenerate, and mating success is adversely affected in all adults that suffered early amputation. The pre-existing relationship between juvenile size and development was a critical determinant of regeneration, however no life history costs of regeneration were evident. I conclude that plasticity in life history facilitates regeneration, and that this may mask trade-offs involved in compensatory effects at the population level.
|2010||二瓶直子，駒形修，小林睦生，吉田政弘，国田正忠，金田弘幸. 2010. 地理情報システムを利用した大阪府におけるセアカゴケグモ咬症リスクエリアの検出 (Geographic Information Systems for Identifying Areas with a Risk of Redback Spider Bites in Osaka Prefecture). 地図 = Map 48(1): 17-23. ==> information only|
|2010||谷川明男. 2010. 日本産クモ類目録 ver. 2010R2. KISHIDAIA (東京蜘蛛談話会) 98: 59-129. ==> PDF|
Stoltz, JA, Andrade MCB. 2010. Female's courtship threshold allows intruding males to mate with reduced effort. Proceedings of the Royal Society B: Biological Sciences 277(1681): 585-592 (DOI: 10.1098/rspb.2009.1554)
Female decision rules can influence the nature and intensity of sexual selection on males, but empirical demonstrations of rules underlying choice are rare. We hypothesized that female choice is largely based on a courtship duration threshold in the Australian redback spider (Latrodectus hasselti) because females kill males before copulation is complete (premature cannibalism) and reduce their paternity if courtship is brief. We used published data to infer that the female's threshold is approximately 100 min of courtship. We support this hypothesis by showing that premature cannibalism is common when the male's courtship duration is below this threshold, but is infrequent and unrelated to duration once courtship exceeds the threshold. We then ask whether females discriminate the source of courtship when rival males compete, as this will determine the effect of the threshold on male competitive tactics. We staged competitions where ‘resident’ males initially courted females in the absence of competition, exceeding the courtship threshold before ‘intruding’ males were introduced. Intruding males mated rapidly but were not prematurely cannibalized by females, in contrast to cases where competition starts before the threshold is surpassed. This suggests females do not distinguish which male satisfies the threshold, allowing intruders to parasitize the courtship efforts of residents. To our knowledge, such exploitation of mating efforts by rival males mediated by a female choice threshold has not been demonstrated elsewhere. Ironically, this female choice threshold and the attendant possibility of courtship parasitism may lead to selection for lower-quality males to recognize and seek out (rather than avoid) webs in which competitors are already present.
Stoltz JA, Hanna R, Andrade MCB. 2010. Longevity cost of remaining unmated under dietary restriction. Functional Ecology 24(6): 1270–1280. (DOI: 10.1111/j.1365-2435.2010.01729.x) ==>HTML ==>PDF|
1. Increases in longevity from dietary restriction (DR) have been linked to the evolution of physiological strategies for maintaining lifetime reproductive output despite periods of nutritional deficiency. If this is the case, then reproductive life history and mating status should determine whether or not dietary restriction increases longevity.
2. We investigate the effects of DR and mating status (mated or unmated) on longevity and lifetime reproductive output and explore mechanisms underlying these patterns by measuring resting energetic rates and changes in mass over time. We study iteroparous female Australian redback spiders (Latrodectus hasselti), which are known to tolerate periods of starvation (ecologically relevant DR) in nature.
3. Mated DR females had the highest longevity of any experimental group, in strong contrast to results for semelparous males of this species [M.M. Kasumovic, M.C.B. Andrade & R.C. Brooks (2009), Biology Letters,5, 636]. Most strikingly, mated females (whether DR or not) had higher longevity than unmated females.
4. Mated females rapidly decreased their resting energetic rates and stopped egg production under DR. Once feeding returned to normal, resting energetic rates of mated females increased immediately, egg sac production continued and there was no net decrease in lifetime reproductive output relative to mated females without DR.
5. This shows DR increases longevity for mated females, but there is a longevity cost of remaining unmated, which may arise because unmated females (regardless of diet) maintained high energetic rates. This may be an evolved pattern of physiological support for reproductive readiness which exerts a fitness cost when mating is delayed. Taken together, these results suggest positive effects of DR on longevity critically depend on reproductive life history (iteroparity or semelparity) and individual mating status.
|2010||[講演要旨] 吉田政弘. 2010. B16 土地区画整理事業に伴うセアカゴケグモの分布について (B16 Distribution of Red back spider attended with readjust the division of land). 衞生動物(第62回日本衛生動物学会大会特集) (The 62nd Annual Meeting of the Japan Society of Medical Entomology and Zoology) ==> information→PDF|
Harari AR, Ziv M, Lubin Y. 2009. Conflict or cooperation in the courtship display of the widow spider, Latrodectus pallidus. Journal of Arachnology 37(3):254-260. (doi: 10.1636/St08-97.1) ==> Abstract 【本文，このサイトからは有料】|
We used experimental manipulations to test adaptive explanations for the courtship display of the male widow spider, Latrodectus pallidus O. Pickard-Cambridge 1872. Two hypotheses have been suggested to explain a long and complex male display: a) Cooperation of males and females in the effort to physically stimulate the female. As the time of male arrival is not predictable, females may delay sexual readiness until the appearance of a courting male. b) Conflict between males and females regarding the display cost. Females impose on the males an energetically costly display that may last several hours as a test of their quality. To test both hypotheses, we manipulated the previous experience of either the male or the female. We presented naive or experienced males (males that had courted and were accepted by females but were prevented from copulating) to females that were either naive or experienced (had been courted by a male but prevented from copulating). We also presented naive males to mated females. Following the stimulation hypothesis, courted females were presumed to have been stimulated to mate and thus were expected to accept non-courting males as mates. Both naive and mated females, however, were expected to await male stimulation before allowing copulation. In contrast, the conflict of interest hypothesis predicts that the female tests each male for quality indicators and therefore a non-courting male should not be accepted as a mate. Mated females, however, should apply a less stringent test to courting males. Our results show that 1) naive females prevented males that did not perform a full courtship display from entering the nest and mounting; 2) naive males courted virgin females with the full display, independent of the female previous courting history; and 3) naive males shortened their courtship when presented with mated females. The results are consistent with the conflict of interest hypothesis.
Jäger P. 2009. Latrodectus mactans nach Deutschland eingeschleppt (Araneae: Theridiidae). Arachnologische Mitteilungen 7: 35-38. ==> PDF[ドイツ語]|
Latrodectus mactans introduced into Germany (Araneae: Theridiidae). Latrodectus mactans (Fabricius, 1775) was recorded from Germany. The species was most likely introduced with cargo from Chicago, USA. Characters of the single female are illustrated for future identification.
Kasumovic MM, Andrade MCB. 2009. A change in competitive context reverses sexual selection on male size. Journal of Evolutionary Biology 22(2): 324–333. (DOI: 10.1111/j.1420-9101.2008.01648.x) ==> HTML ==> PDF|
In studies of sexual selection, larger size is often argued to increase male fitness, and relatively smaller males are explained by genetic and/or environmental variation. We demonstrate that a size–development life-history trade-off could underlie the maintenance of a broad, unimodal distribution of size in male redback spiders (Latrodectus hasselti). Larger males are superior in direct competition, but redback males mature rapidly at small size in the presence of females. In field enclosures, we simulated two competitive contexts favouring development of divergent male sizes. Relatively smaller males lost when competing directly, but had 10 times higher fitness than relatively larger males when given the temporal advantage of rapid development. Linear selection gradients confirmed the reversal of selection on size, showing that it is critical to consider life-history decisions underlying the development of traits related to fitness.
Kasumovic MM, Brooks RC, Andrade MCB. 2009. Body condition but not dietary restriction prolongs lifespan in a semelparous capital breeder. Biology Leters 5(5): 636-638 (DOI: 10.1098/rsbl.2009.0335) ==> Abstract ==>PDF|
Effects of diet on longevity are complex because acquired resources are shared among growth, reproduction and somatic maintenance. We simplify these axes by examining how dietary restriction and competitive contexts affect longevity using semelparous males of the Australian redback spider (Latrodectus hasselti). Plastic development of L. hasselti males results in trade-offs of body condition against faster development if females are present, facilitating scramble competition. In the absence of females, males develop slowly as high body condition adults, and are better equipped for mate searching. Here we focus on effects of diet and competitive context on body condition and longevity. Although male survival depended on body condition and exercise, contrary to studies in a wide range of taxa, dietary restriction did not increase longevity. However, there was an interactive effect of diet and competitive context on lifespan, because high-diet males reared in the absence of females lived longer than males reared in the presence of females. Thus males near females pay a survival cost of developing rapidly. This shows that life-history trade-offs affected by competitive context can impose longevity costs independent of the direct energy expenditure of searching, courtship, competition or reproduction.
Maillaud C, Jourdan H, Winkel K, Arnaud G, Lafforgue P, Durand, F. 2009. Latrodectism in New Caledonia: First Report of Presumed Redback Spider (Latrodectus hasselti) Envenomation. Wilderness & Environmental Medicine 20(4): 339–343. ==> Abstract ==> PDF|
We describe a recent case of presumed redback spider (Latrodectus hasselti) envenomation observed near Noumea in New Caledonia. This is the first local reported case in this archipelago, where L. hasselti is currently considered a native species. We highlight the challenge of providing appropriate analgesia in this situation and believe that the use of specific redback spider antivenom should be considered in New Caledonia.
|2009||清水裕行，西川喜朗. 2009. セアカゴケグモ (特集 2 外来昆虫類の脅威). 遺伝 63(3): 102-108. ==> information only|
Stoltz JA, Andrade MCB. 2009. Female's courtship threshold allows intruding males to mate with reduced effort. Proceeding of the Royal Society B 277(1681): 585–592 (DOI: 10.1098/rspb.2009.1554) ==> Abstract ==> HTML ==>PDF|
Female decision rules can influence the nature and intensity of sexual selection on males, but empirical demonstrations of rules underlying choice are rare. We hypothesized that female choice is largely based on a courtship duration threshold in the Australian redback spider (Latrodectus hasselti) because females kill males before copulation is complete (premature cannibalism) and reduce their paternity if courtship is brief. We used published data to infer that the female's threshold is approximately 100 min of courtship. We support this hypothesis by showing that premature cannibalism is common when the male's courtship duration is below this threshold, but is infrequent and unrelated to duration once courtship exceeds the threshold. We then ask whether females discriminate the source of courtship when rival males compete, as this will determine the effect of the threshold on male competitive tactics. We staged competitions where ‘resident’ males initially courted females in the absence of competition, exceeding the courtship threshold before ‘intruding’ males were introduced. Intruding males mated rapidly but were not prematurely cannibalized by females, in contrast to cases where competition starts before the threshold is surpassed. This suggests females do not distinguish which male satisfies the threshold, allowing intruders to parasitize the courtship efforts of residents. To our knowledge, such exploitation of mating efforts by rival males mediated by a female choice threshold has not been demonstrated elsewhere. Ironically, this female choice threshold and the attendant possibility of courtship parasitism may lead to selection for lower-quality males to recognize and seek out (rather than avoid) webs in which competitors are already present.
Stoltz JA, Elias DO, Andrade MCB. 2009. Male courtship effort determines female response to competing rivals in redback spiders. Animal Behaviour 77(1): 79–85. ==> Abstract 【PDF download可】|
When males compete with rivals in the presence of females, there may be a trade-off between courtship and competition. We examined responses of female redback spiders, Latrodectus hasselti, to courtship from rival males under different competitive contexts. We paired size-matched males with females, and assessed correlates of male mating success. We compared these results to published data between females and single males or size-mismatched rivals. Size-matched males attempted copulation after a brief courtship, a strategy similar to smaller, ‘sneaker’ males in size-mismatched competitions. We also found context-dependent differences in female remating frequency and premature cannibalism. In size-mismatched and single-male trials, females prematurely cannibalized smaller males and males that mated quickly, but this was not the case when rivals were size-matched. However, in both types of competitive trials, males that mated rapidly paid a fitness cost. The courtship duration of the first male to mate was inversely related to the number of copulations that females accepted from that male's rival. Thus, females use premature cannibalism to reduce the paternity of males that minimize investment in courtship if they are clearly distinguishable from their rivals (mismatched context), but they allow males to continue to compete if they are similar in quality (matched context). In both cases, biases in female remating behaviour favoured males that invested in courtship. We conclude that female reproductive behaviour partly depends on the relative size of competing males, but that male fitness depends heavily on investment in courtship.
田中生男. 2009. 虫などによる健康問題. JIM 19(6): 416-419. ==> PDF (本文有料)|
... ムカデ綱 トビズムカデなど 真性クモ目：セアカゴケグモ、カバキコマチグモなど ダニ目 クモ網 マダニ科：シュルツェマダニ、...
Vink CJ, Sirvid PJ, Malumbres-Olarte J, Griffiths JW, Paquin P, Paterson AM. 2009. Species status and conservation issues of New Zealand's endemic Latrodectus spider species (Araneae: Theridiidae). Invertebrate Systematics 22(6): 589–604. ==> Abstract 【本文，このサイトからは有料】|
New Zealand has two endemic widow spiders, Latrodectus katipo Powell, 1871 and L. atritus Urquhart, 1890. Both species face many conservation threats and are actively managed. The species status of the Latrodectus spiders of New Zealand was assessed using molecular (COI, ITS1, ITS2) and morphological methods and with cross-breeding experiments. Latrodectus katipo and L. atritus were not found to be reciprocally monophyletic for any of the gene regions or morphological traits. Other than colour, which is variable, there were no morphological characters that separated the two species, which cross-bred in the laboratory and produced fertile eggsacs. Colour variation is clinal over latitude and correlates significantly with mean annual temperature. We conclude that L. atritus is a junior synonym of L. katipo. An example of introgression from the Australian species L. hasseltii Thorell, 1870 was also detected and its conservation implications are discussed.
Keywords: conservation genetics, cytochrome oxidase subunit 1 (COI), DNA, internal transcribed spacer regions (ITS), intraspecific variation, Latrodectus atritus, Latrodectus hasselti, Latrodectus hasseltii, Latrodectus katipo, phylogenetics, taxonomy.
Bertani R, Fukushima CS, Martins R. 2008. Sociable widow spiders? Evidence of subsociality in Latrodectus Walckenaer, 1805 (Araneae, Theridiidae). Journal of Ethology 26(2) 299-302 (DOI:10.1007/s10164-007-0082-8) ==> Abstract & PDF ==> HTML|
A first case of subsociality is reported for the genus Latrodectus. Individuals were found sharing the same web and feeding together. In captivity they showed mutual tolerance and communal feeding. This finding is remarkable for two reasons. First, widow spiders, even compared with other spiders, are famously aggressive and cannibalistic so that social behavior in the genus was unexpected. Second, the genus nests outside the “Anelosimus + lost colulus” clade where all the other social theridiids are found.
Kobelt M, Nentwig W. 2008. Alien spider introductions to Europe supported by global trade. Diversity and Distributions 14(2): 273–280 (DOI: 10.1111/j.1472-4642.2007.00426.x) ==> HTML & PDF|
Global trade is permanently ongoing and increases its volume every year. In this study, the occurrence of 87 unintentionally introduced spider species alien to Europe is analysed. The analysis includes (1) the introduction potential of six different origin areas of the world according to trade volume, area size, and geographical distance; (2) the body size of native and alien species; and (3) occurrence in or at buildings (synanthropic) or in natural habitats. We found the eastern Palearctic as the most influencing origin area with 44 introduced spider species to Europe. The eastern Palearctic and the Indomalayan provided a significantly higher number of introductions than expected, whereas the Nearctic, Neotropical, and Afrotropical provided a significantly lower number of introduced species than expected. This can be explained with their lower trade volume, smaller area, larger geographical distance to Europe, and stronger climate differences to Europe. Comparing the body size of introduced and native European spider species of the same family, we found for Theridiidae significantly larger alien spiders and for all other tested families a trend to a larger body size of alien species compared to the native spiders. The family affiliation of alien spiders is the most important factor for synanthropic occurrence in Europe. On the base of a very conservative estimation of spider species introductions to Europe combined with possible effects of climate change, we predict for the near future a permanent increase in the number of alien spider species in Europe.
二瓶 直子，駒形 修，吉田 政弘，水谷 正時，金田 弘幸，小林 睦生. 2008. 西宮市におけるセアカゴケグモ Latrodectus hasseltii (Araneae:Theridiidae)の防除対策が発生動態に与えた影響. 衞生動物 59(3): 153-162. [Nihei N, Komagata O, Yoshida M, Mizutani M, Kaneta H, Kobayashi M. 2008. Effects of control measures on the prevalence of the redback spider Latrodectus hasseltii (Araneae: Theridiidae) in Nishinomiya City, Hyogo Prefecture, Japan. Medical Entomology and Zoology 59(3): 153-162] ==> Abstract and PDF|
The redback spider (RBS) was discovered at a reclaimed island site in Nishinomiya City, Hyogo Prefecture in October 2000. Nishinomiya City consequently initiated field surveys and control programmes in October of the same year. The overall results of the control measures up to October 2005 were summarized according to the survey period, month, address in town/street, number of collected male/female/egg sac specimens, and number of inspectors. Some of the data were then plotted onto a map using GIS and remote sensing by aerial photographs in order to analyze the distribution, dispersal fluctuations and causal factors thereof, the effectiveness of control programmes and the possibility of eradication. The number of collected specimens peaked in 2002 and then declined, but the distribution of the spiders has expanded rapidly since 2003. In addition, significant areal differences in the density and habitation frequency have occurred. Furthermore, analysis of aerial photographs and development related documentation reveal a clear relationship between the invasion and establishment of RBS and the subsequent urgent housing development after the Great Hanshin-Awaji Earthquake (January,1995). The results clearly show that the survey season, continuous monitoring and control activity of RBS are extremely important to reduce the population density of RBS in the accidentally infested areas.
|2008||二瓶直子，小林睦生，吉田政弘. 2008. 近畿地方におけるセアカゴケグモの分布拡散と今後の課題. 生活と環境 53(12): 44-50. ==> information only|
野嶋宏一. 2008. 岡山県産クモ類 目録. KISHIDAIA (東京蜘蛛談話会) 94: 59-81. ==> PDF|
...セアカゴケグモ 倉敷市（山陽新聞，平成20年4月27日 朝刊）...
Perampaladas K, Stoltz JA, Andrade MCB. 2008. Mated redback spider females re‐advertise receptivity months after mating. Ethology 114: 589–598. ==> PDF|
In many species, selection acts on males to recognize female reproductive status at a distance using pheromones. Unmated females may actively seek to attract males; however, mated females may become cryptic to avoid attracting additional males if multiple matings are costly. Although females of many species cease pheromone production after mating, it is often unclear whether this is a strategic part of a female reproductive strategy, or whether this is because of chemical manipulation by males. If variation in pheromone production is part of the female’s strategy, then we predicted mated females should eventually re-advertise receptivity if the benefits of multiple mating increase with time since copulation (e.g. because of sperm depletion). Here, we tested this prediction in Australian redback spiders (Latrodectus hasselti). First, we replicated earlier results by showing that virgin males discriminate female maturity and mating status based exclusively on web-borne chemicals. Our results show this difference must arise from a change in chemical deposition in the web as we controlled for web volume differences between mated and virgin females. Male activity on extracts from webs of virgin females exceeded activity on a solvent control and on extracts of webs of just-mated females—confirming that female redbacks cease pheromone production immediately after mating. Second, we tested a new prediction that mated females might re-advertise receptivity near the end of their normal breeding season to replenish diminished sperm stores prior to overwintering. Consistent with the prediction of strategic advertisement, we show that male activity on extracts from females’ webs increased significantly 3 mo after the female first mated (typical length of the breeding season). Thus, these females had begun to add pheromone to their web again. At this time, 26% of these females re-mated with a second male. If females re-advertise receptivity to ensure adequate sperm stores, then we predicted a positive relationship between female reproductive output during the 3-mo interval after copulation and the subsequent intensity of male response to web extracts. However, differences in male activity time were not related to the total number of spiderlings or the number of egg sacs a female had produced during the 3-mo interval after the first copulation. This result could arise if male chemical manipulation of female receptivity decreases with time after copulation, or if the testing interval used in our study was too long to reveal variation in sperm depletion in females. Thus, although our results are consistent with the idea that females strategically alter pheromonal advertisement, we cannot distinguish this from the hypothesis that female receptivity arises from chemical manipulation by male
Segoli M, Arieli R, Sierwald P, Harari AR, Lubin Y. 2008. Sexual cannibalism in the brown widow spider (Latrodectus geometricus). Ethology 114(3): 279–286. (DOI: 10.1111/j.1439-0310.2007.01462.x) ==> HTML ==> PDF|
Sexual cannibalism may represent an extreme form of male monogamy. According to this view, males gain reproductive success by sacrificing themselves to females. We studied the occurrence and timing of sexual cannibalism in the brown widow spider Latrodectus geometricus and compared male courtship and mating behavior with virgin and with previously mated females. We found that events of sexual cannibalism are frequent, that they occur during copulation and that males initiate cannibalism by placing the abdomen in front of the female’s mouth-parts during copulation (somersault behavior). Both the somersaults and mating occurred more frequently with virgins than with previously mated females. Our results support the hypothesis that sexual cannibalism is a male strategy in this species. The somersault behavior was previously known only from the redback spider, Latrodectus hasselti. It is as yet unknown whether self-sacrifice has evolved more than once in this genus.
Segoli M, Lubin, Harari AR. 2008. Frequency and consequences of damage to male copulatory organs in a widow spider. Journal of Arachnology 36(3):533-537. (doi: 10.1636/St07-30.1) ==> Abstract 【本文，このサイトからは有料】|
Copulatory organ breakage, in which a portion of the male's genitalia breaks off and remains in or attached to the female's genitalia may represent a male strategy of high investment in a single mating. Such a strategy is expected when mating opportunities for males are limited and competition for females is high. We studied costs and benefits for males as a consequence of male organ breakage in the white widow spider (Latrodectus pallidus O. Pickard-Cambridge 1872). In order to estimate the frequency and consequences of such damage we provided each male with four virgin females simultaneously in an outdoors enclosure. We recorded male mating success and loss of the tip of the embolus (the male intromittent organ) inside the female's genitalia for each male. In order to test the effect of the broken tip as a mating plug, we collected females from natural populations and observed the location of embolus tips inside their genitalia. We found that damage to the male organ was frequent but did not necessarily result in male sterility. From the field data, we found that the likelihood of a second embolus tip entering the spermatheca is significantly lower than that of the first tip, suggesting the possibility that the tip functions as a partial mating plug.
Stoltz JA, Elias DO, Andrade MCB. 2008. Females reward courtship by competing males in a cannibalistic spider. Behavioral Ecology and Sociobiology 62(5): 689-697 (DOI:10.1007/s00265-007-0493-0) ==> Abstract & PDF ==> HTML|
Despite widespread recognition that intersexual interactions shape reproductive strategies, studies of male competition do not typically include effects imposed by females. In cannibalistic redback spiders, escalated fighting between rival suitors is predicted, as males are unlikely to mate with more than one female, and strong first-male sperm precedence favours mating with virgins. In staged competitions for matings between size mismatched rivals, smaller males adopted an alternative sneaking strategy. However, despite initial agonistic interactions, larger males did not pursue or incapacitate smaller males. When inter-male competition occurred, females struck at males frequently, although strikes were rarely seen when males courted in the absence of a rival. After minimal fighting, larger males engaged in significant courtship (3 h) rather than killing inferior rivals. Prolonged courtship was favoured by female behaviour, as males that attempted rapid copulation (smaller, sneaking males) were cannibalised before mating was completed. This premature cannibalism significantly decreases paternity in redback spiders. Thus, significant features of male competitive behaviour (i.e. prolonged courtship by larger males) may be predicted with consideration of the female’s response to male reproductive strategies. Although the effect of females may be more subtle in systems without the extreme reversed size-dimorphism of redbacks, these results suggest that female interests should be explicitly considered when studying inter-male interactions.
Vink CJ, Sirvid PJ, Malumbres-Olarte J, Griffiths JW, Paquin P, Paterson AM. 2008. Species status and conservation issues of New Zealand's endemic Latrodectus spider species (Araneae: Theridiidae). Invertebrate Systematics 22(6): 589–604. ==> Abstract 【本文，このサイトからは有料】|
New Zealand has two endemic widow spiders, Latrodectus katipo Powell, 1871 and L. atritus Urquhart, 1890. Both species face many conservation threats and are actively managed. The species status of the Latrodectus spiders of New Zealand was assessed using molecular (COI, ITS1, ITS2) and morphological methods and with cross-breeding experiments. Latrodectus katipo and L. atritus were not found to be reciprocally monophyletic for any of the gene regions or morphological traits. Other than colour, which is variable, there were no morphological characters that separated the two species, which cross-bred in the laboratory and produced fertile eggsacs. Colour variation is clinal over latitude and correlates significantly with mean annual temperature. We conclude that L. atritus is a junior synonym of L. katipo. An example of introgression from the Australian species L. hasseltii Thorell, 1870 was also detected and its conservation implications are discussed. Keywords: conservation genetics, cytochrome oxidase subunit 1 (COI), DNA, internal transcribed spacer regions (ITS), intraspecific variation, Latrodectus atritus, Latrodectus hasselti, Latrodectus hasseltii, Latrodectus katipo, phylogenetics, taxonomy.
Brandt Y, Andrade, MCB. 2007. Testing the gravity hypothesis of sexual size dimorphism: are small males faster climbers? Functional Ecology 21(2): 379-385. ==> Abstract ==> HTML ==> PDF|
1 Moya-Laraño et al. (2002; Evolution 56, 420–425) showed that female-biased sexual size dimorphism is more pronounced in tree-dwelling spider species than in species inhabiting lower-lying substrates. They proposed the Gravity Hypothesis for sexual size dimorphism: small size should be advantageous for males in habitats where successful mate searching requires climbing, because mass-specific power and hence the speed of climbing against gravity, must decrease with increasing size.
2 Their biomechanical model is based on a false premise, that the cross-sectional area of a muscle determines its power output. In fact, muscle power is proportional to muscle volume, and hence mass-specific power should be independent of size. We therefore predict, contrary to the Gravity Hypothesis, that climbing speed should be independent of body size.
3 We tested these contrasting predictions using adult male Western black widow spiders >Latrodectus hesperus, a species in which males span a broad range of sizes.
4 In accordance with our prediction, and contrary to the Gravity Hypothesis, we found no relationship between vertical climbing speed and any of a series of size measures, whereas on a horizontal surface, speed was positively related to size.
5 Our results, as well as the error we exposed in the biomechanical model underlying the Gravity Hypothesis, indicate that selection for vertical climbing speed in males cannot account for patterns of sexual size dimorphism in spiders.
Nihei N, Komagata O, Mochizuki K, Kobayashi M. 2007. Epidemiological analysis of infectious diseases and the establishment of a surveillance system through remote sensing using ALOS images. Proceedings of the First Joint PI Symposium of ALOS Data Nodes of ALOS Science Program in Kyoto, November 2007, LUG12. ==> PDF|
This report pertains to the disease surveillance system for schistosomiasis japonica, a larval habitat analysis of vector mosquitoes, and biting case analysis of imported venomous spider. In order to fully grasp the resurgence of infectious diseases and the distribution of their vector animals, detailed habitation analyses are conducted, and spatial information compiled through GPS and satellite images. GIS is used to map these data, and the regional differences and environmental characteristics of distribution are analyzed. The ideal conditions for habitats of medical important animals were clarified and the significant areas subsequently identified through environmental analysis of the distribution area using ALOS AVNIR-2 images and the vegetation index NDVI. We are currently attempting to estimate new habitat establishment and future distribution for wide area by generalizing the characteristics of a limited research area. Furthermore, this technique is a prompt and accurate way to grasp and monitor rapidly changing environmental conditions.
|2007||[講演要旨] 二瓶直子，吉田政弘，国田正忠，駒形修，金田弘幸，小林睦生. 2007. B12 大阪府におけるセアカゴケグモ生息密度と咬症例について (B12 Relationship between biting cases and the population density of red back spider in Osaka Prefecture, Japan). 衞生動物 58(Supplement)(第59回日本衛生動物学会大会特集): 48. ==> information→PDF|
Segoli M, Lubin Y, Harari AR. 2007. The effect of dietary restriction on the lifespan of males in a web-building spider. Evolutionary Ecology Research 9(4): 697-704. ==> Abstract PDF??|
Question: Do web-building spider males respond to dietary restriction by increased lifespan, as is observed in many other organisms?
Hypothesis: Adult males normally do not feed, have extremely high extrinsic mortality rates during mate search, and mate only once, hence they are less likely to benefit from increased lifespan in terms of future reproductive success. Accordingly, they are not expected to respond to dietary restriction by increased lifespan.
Organism: Adult white widow spider (Latrodectus pallidus) males.
Methods: Virgin adult males were kept on a low diet or fed ad libitum. Longevity of males was recorded.
Results: As opposed to our predictions we found that food-restricted male spiders survived longer than males that fed ad libitum.
Shukla S, Broome VG. 2007. First report of the brown widow spider, Latrodectus geometricus CL Koch (Araneae: Theridiidae) from India. Current Science 93(6): 775-777. ==> Abstract ==> PDF|
The Theridiids or comb-footed spiders comprise a large and diverse family. They are nocturnal and web-living. Spiders of the Theridiidae family build irregular snares, from the threads of which they suspend themselves in an inverted position waiting for their prey. They are distinguished from other spiders by the presence of a distinct comb on the tarsus of the fourth pair of legs, consisting of a row of strong curved and toothed setae, bristles of which are onger than those on the dorsal side of tarsus IV, and their labium is not rebordered1,2. The family is best known due to the notoriety of its genus Latrodectus, also called widow spider.
Stoltz JA, McNeil JN, Andrade MCB. 2007. Males assess chemical signals to discriminate just-mated females from virgins in redback spiders. Animal Behaviour 74(6): 1669–1674. ==> Abstract 【PDF download可】|
In species where virgin females have higher reproductive value to males than nonvirgin females, selection will favour males that can discriminate female reproductive status. Similarly, while virgin females may actively seek to attract males, nonvirgin females may seek crypticity after mating if copulation is costly. Here we show that Australian redback spider males, Latrodectus hasselti, discriminate female maturity and mating status based exclusively on web-borne chemicals. Male activity on extracts from webs of virgin females significantly exceeded activity on extracts of webs of juveniles, nonvirgin females and solvent controls. While this level of discernment of female reproductive status has been found in other spiders, here we show that discrimination of web-bound chemicals produced by virgin females disappears rapidly after these females mate. Extracts of webs built by females immediately after copulation elicited no more interest from males than did solvent controls. Redback males dismantle much of their mate's web during courtship, and these results suggest that the web rebuilt by females after mating would not trigger male courtship. We speculate that this rapid shift would significantly reduce the opportunity for polyandry in nature.
|2007||Van Keer, Koen. 2007. Exotic spiders (Araneae): Verified reports from Belgium of imported species (1976-2006) and some notes on apparent neozoan invasive species. Nieuwsbrief van de Belgische Arachnologische Vereniging 22: 45-54.|
|2007||[講演要旨] 吉田政弘，二瓶直子，駒形修，金田弘幸，小林睦生. 2007. B11 セアカゴケグモ分布の現状 (B11 Recent distribution of Latrodectus hasseltii). 衞生動物 (第59回日本衛生動物学会大会特集) (The 59th Annual Meeting of the Japan Society of Medical Entomology and Zoology) 58(Supplement): 48. ==> information→PDF|
|2008||[講演要旨] 吉田永祥，池田芳春，松尾光子，三好龍也，内野清子，田中智之. 2008. 10 堺市内陸部におけるセアカゴケグモ駆除後の個体群動態 (10.The population dynamics of Latrodectus hasseltii (Araneae: Theridiidae) after control at inland in Sakai city). 衞生動物 (第 62 回日本衛生動物学会西日本支部大会講演要旨) 59(2): 117. ==> information→PDF|
|2007||[講演要旨] 吉田永祥，松尾光子，三好龍也，内野清子，田中智之. 2007. 2 堺市におけるセアカゴケグモ発見後の分布状況 (Distribution of Latrodectus hasseltu in Sakai city). 衞生動物 (第61回日本衛生動物学会西日本支部大会講演要旨) (Contributed Paper,Proceedings of the 61st Annual Meeting of Western Region) 58(2): 126. ==> information→PDF|
Díaz-Mizos FA, Díaz ÁB, Herrera VC, Pérez MS. 2006. Latrodectismo: Presentación de Cuatro Casos. Poisoning by Latrodectus. A four case presentation. Mediciego 12.2 ==> web page only?|
...no es exclusivo del género Latrodectus<.1 Se denominan “viudas negras” a las arañas del género en que predomina el color negro azabache o matices oscuros como Latrodectus mactans, Latrodectus hesperus, Latrodectus variolus, Latrodectus hasseltii< y Latrodectus...
Kasumovic MM, Andrade MCB. 2006. Male development tracks rapidly shifting sexual versus natural selection pressures. Current Biology 16(7): R242-R243 (doi: 10.1016/j.cub.2006.03.017) ==> HTML ==> PDF|
Miller J. 2006(?) Widow spiders. ==> websiteのみ|
...The Australian redback spider (Latrodectus hasselti): its introduction and potential for establishment and distribution in New Zealand. The stereotyped behavior of sexual cannibalism in Latrodectus hasselti Thorell (Araneae: Theridiidae), the Australian redback spider...
|2006||[講演要旨] 二瓶直子，小林睦生，吉田政弘，田所克己，金田弘幸. 2006. B24 空中写真による兵庫県西宮市のセアカゴケグモ生息動向の解析および防除対策の評価. 衞生動物 57(Supplement): 66. (一般講演, 第58回日本衛生動物学会大会) [B24 Spatial analysis of redback spider, Latrodectus hasseltii, distribution and evaluation of the control measure in Nishinomiya City, Hyogo] ==> PDF|
Mito T. 2006. Establishment and enforcement of the new Invasive Alien Species Act in Japan. pp. 35-44. In: Koike F, Clout MN, Kawamichi M, Poorter MD and Iwatsuki K. ed. Assessment and Control of Biological Invasion Risks. Shoukadoh Book Sellers, Kyoto, Japan and IUCN, Gland, Switzerland. ==> PDF|
Hundreds of millions of alien organisms are introduced into Japan every year. Some have become ‘invasive,’ having adverse effects on ecosystems, human safe ty, or agriculture, forestry and fisheries. Considering that the Japanese regulatory system has not dealt with the issue comprehensively, taking into account various suggestions from many entities concerned, and aiming to implement the provisions of Article 8 (h) stipulated by the Convention on Biological Diversity, the Japanese Cabinet finalised a draft of the Invasive Alien Species Act and submitted it to the Japanese Diet (= Parliament) in March, 2004. The framework consists of the following three main points: (1) "Invasive Alien Species" (IAS) shall be designated by the Act as having adverse effects on ecosyste ms, human safety, or agriculture, forestry and fisheries. Raising, planting, storing, carrying, and importing IAS shall be prohibited with the exception of specified cases such as by obtaining permission from the competent ministers. (2) National/local governments, Non-Profit Organisations, and other entities concerned shall take appropriate measures to mitigate the impact of IAS that already exist in Japan. (3) "Uncategorised Alien Species " (UAS), which are suspected IAS, shall need detailed investigation by the Japanese government for up to six months in order to be allowed to be imported into Japan. The Diet passed the draft without amendments and the new Invasive Alien Species Act was promulgated as of 2 June, 2004. Following the establishment, the Japanese Cabinet made a basic policy on 15 October, 2004, for effective implementation of the Act. In addition to designation of UAS, 37 different types of alien species were selected as IAS for the first step, based on suggestions by academic experts and the Act was enforced on 1 June, 2005. The second round of designation was completed on 1 February, 2006, with 43 additional IAS. We continue our consideration of additional designation as well as strategies for eradication and control of IAS.
Keywords: alien species; biodiversity; IAS; invasive alien species; importation; LORCA; mitigation, regulation; UAS; uncategorised alien species.
Prenter J, MacNeil C, Elwood RW. 2006. Sexual cannibalism and mate choice. ANIMAL BEHAVIOUR 71(3): 481-490. ==> HTML [PDF download可]|
Sexual cannibalism, where a female kills and consumes a courting male, represents an extreme form of sexual conflict and has been proposed as a mechanism of mate choice. We evaluate the evidence for mate choice through premating sexual cannibalism via mate rejection, other indirect mechanisms of mate ‘choice’ and choice in postmating sexual cannibalism. We highlight a paucity of investigations, particularly of field studies, and note gaps in our knowledge. There is empirical support for the size-dependent sexual cannibalism predicted by mate choice through premating sexual cannibalism. This may represent mate choice operating on absolute male size but it could be a by-product of female foraging behaviour and greater vulnerability of relatively smaller males. Thus, indirect mate choice is as plausible an explanation of size-dependent sexual cannibalism as is direct mate choice based on discrimination of male traits. Direct female choice, mediated through premating sexual cannibalism, has yet to be demonstrated. We suggest a framework for distinguishing direct and indirect choice and note an absence of information on which to test it. There is evidence for sequential mate choice in postmating sexual cannibalism, but the nature or basis of the female's discriminatory behaviour remains unclear. Costs and long-term fitness benefits of the putative mate choice have been largely ignored. Reversed sexual cannibalism, in which the male eats the female, presumably occurs when the gain from food is high and potential gain from mating low and probably has little to do with mate choice.
Segoli M, Harari AR, Lubin Y. 2006. Limited mating opportunities and male monogamy: a field study of widow spiders, Latrodectus pallidus (Theridiidae). Animal behaviour 72(3): 635–642. ==> HTML ==> PDF|
The reproductive success of a male is thought to be a function of the number of females he fertilizes. Nevertheless, various naturally occurring male behaviours seem to reduce dramatically the probability of obtaining additional matings. Such behaviours are expected when mating opportunities are limited for males and when males compete strongly for females or fertilizations. In widow spiders, males cohabit in females’ webs, engage in long courtship displays, often lose the tip of one or both emboli (copulatory organs) inside the female’s genital tract during copulation and are occasionally cannibalized by the female. We investigated conditions that may favour the evolution of a high-investment strategy of mating in white widow, Latrodectus pallidus, males. We followed male movements between females in a patchily distributed population of white widows and estimated the minimum number of males with which fieldcaught females mated from the number of embolus tips found in their genital tracts. The encounter rate of males with females was low with less than 20% of the searching males reaching a female. Females, in contrast, frequently mated with more than one male (up to six). We suggest that low encounter rates with females, coupled with high intrasexual competition, drives the evolution of a strategy of high investment by males in a single mating, as was observed in the white widow spider.
Snow LSE, Abdel‐Mesih A, Andrade MCB. 2006. Broken Copulatory Organs are Low‐Cost Adaptations to Sperm Competition in Redback Spiders. Ethology 112(4): 379-389 (DOI: 10.1111/j.1439-0310.2006.01163.x) ==> HTML ==> PDF|
In some spiders, a discrete portion of the male's copulatory organ (the apical sclerite) breaks off during copulation and remains in the female's reproductive tract. Apical sclerites may prevent insemination by rivals (sperm competition), stimulate females to favourably bias paternity (cryptic choice) or breakage may reflect sexual conflict over copulation duration with little direct effect on paternity. It has been assumed that any benefits of organ breakage are balanced by a large cost (male sterility) in species where males could otherwise mate multiply, but this has never been experimentally tested. We examined these ideas in the Australian redback spider (Latrodectus hasselti Thorell 1870, Araneae: Theridiidae), a species where males are functionally sterile after one normal mating. We experimentally removed sclerites and found males were able to mate, had similar copulation durations and transferred similar numbers of sperm as males with intact sclerites. Benefits of organ breakage were examined by forcing intact, rival males to inseminate the same or opposite reproductive tracts (female have paired, independent tracts in this taxon) and assessing paternity as a function of sclerite location. As predicted, apical sclerites were typically deposited at the entrance to the female's sperm storage organ, where they could physically block insemination by rivals. First male precedence was common when males inseminated the same tract and deposited sclerites at the entrance to the spermatheca, but not when sclerites were found elsewhere in the tract, or when rivals inseminated opposite tracts (where physically blocking rivals was impossible). Our data show that, in redbacks, copulatory organ breakage is not a side-effect of sexual conflict, is unlikely to be a cue for cryptic female choice, but allows males to avoid sperm competition. Moreover, copulatory organ damage can have minimal reproductive cost for males, so assumptions of sterility after organ breakage are unjustified without supporting data.
Andrade MCB, Gu L, Stoltz JA. 2005. Novel male trait prolongs survival in suicidal mating. Biology Letters 1: 276–279 (DOI: 10.1098/rsbl.2005.0318) ==> Abstract ==> PDF|
Male redback spiders (Latrodectus hasselti) maximize paternity if they copulate twice with their cannibalistic mate. Facilitating cannibalistic attack during their first copulation yields paternity benefits. However, females have paired sperm-storage organs inseminated during two separate copulations, so males that succumb to partial cannibalism during the first copulation lose at least 50% of their paternity to rivals. In this paper, we describe a novel male trait—an abdominal constriction that appears during courtship—that allows males to survive and mate with females for a second time, despite the substantial cannibalistic damage inflicted during the first copulation. Constricted males that were wounded to simulate early cannibalism had higher endurance, greater survivorship, longer subsequent courtship and higher mating success than wounded males that were not constricted. Constriction was not found in a non-sacrificial congener that rarely survived simulated cannibalism, and the protective effect of constriction in redbacks was specific to the type of damage inflicted by females during the first copulation. Thus, the abdominal constriction allows males to overcome the potential fitness limit imposed by their own suicidal strategy—paradoxically, by prolonging survival across two cannibalistic copulations.
Andrade MCB, Kasumovic MM. 2005. Terminal investment strategies and male mate choice: extreme tests of Bateman. Integrative and Comparative Biology 45(5): 838-847. (doi: 10.1093/icb/45.5.838) ==> Abstract ==> HTML ==> PDF|
Bateman's principle predicts the intensity of sexual selection depends on rates of increase of fecundity with mating success for each sex (Bateman slopes). The sex with the steeper increase (usually males) is under more intense sexual selection and is expected to compete for access to the sex under less intense sexual selection (usually females). Under Bateman and modern refinements of his ideas, differences in parental investment are key to defining Bateman slopes and thus sex roles. Other theories predict sex differences in mating investment, or any expenditures that reduce male potential reproductive rate, can also control sex roles. We focus on sexual behaviour in systems where males have low paternal investment but frequently mate only once in their lifetimes, after which they are often killed by the female. Mating effort (=terminal investment) is high for these males, and many forms of investment theory might predict sex role reversal. We find no qualitative evidence for sex role reversal in a sample of spiders that show this extreme male investment pattern. We also present new data for terminally-investing redback spiders (Latrodectus hasselti). Bateman slopes are relatively steep for male redbacks, and, as predicted by Bateman, there is little evidence for role reversal. Instead, males are competitive and show limited choosiness despite wide variation in female reproductive value. This study supports the proposal that high male mating investment coupled with low parental investment may predispose males to choosiness but will not lead to role reversal. We support the utility of using Bateman slopes to predict sex roles, even in systems with extreme male mating investment.
Berendonck B, Greven H. 2005. Genital structures in the entelegyne widow spider Latrodectus revivensis (Arachnida; Araneae; Theridiidae) indicate a low ability for cryptic female choice by sperm manipulation. Journal of Morphology 263(1): 118–132. (DOI: 10.1002/jmor.10296) ==> HTML ==> PDF|
The female genital structures of the entelegyne spider Latrodectus revivensis are described using semithin sections and scanning electron microscopy. Apart from the tactile hairs overhanging the opening of the atrium, the contact zones of the female epigynum are devoid of any sensilla, indicating that the female does not discriminate in favor or against males due to their genital size or stimulation through copulatory courtship. The dumb-bell shape and the spatial separation of the entrance and the exit of the paired spermathecae suggest that they are functionally of the conduit type. Not described for other entelegyne spiders so far, the small fertilization ducts originating from the spermathecae of each side lead to a common fertilization duct that connects the spermathecae to the uterus externus. During oviposition, it is most likely that spermatozoa are indiscriminately sucked out of the spermathecal lumina by the low pressure produced by the contraction of the muscle extending from the epigynal plate to the common fertilization duct. As no greater amounts of secretion are produced by the female during oviposition, and no activated sperm are present within the female genital tract, the secretion produced by the spermathecal epithelium does not serve in displacement or (selective) activation of spermatozoa. These findings suggest that female L. revivensis are not able to exert cryptic female choice by selectively choosing spermatozoa of certain males.
Gage MJG. 2005. Evolution: sex and cannibalism in redback spiders. Current Biology 15(16): R630–R632. ==> HTML ==> PDF|
Female redback spiders cannibalise mating males. New research has shown they have evolved two separate sperm storage organs, allowing them to make post-copulatory paternity choices. Counter-adaptation by males, to maximise paternity after cannibalism, has led to the evolution of an abdominal constricting mechanism, which enhances short-term survival and mating success after attack by the female and maximises the chances of inseminating both sperm storage sites.
Griffiths JW, Paterson AM, Vink CJ. 2005. Molecular insights into the biogeography and species status of New Zealand&'s endemic Latrodectus spider species; L. katipo and L. atritus (Araneae, Theridiidae). Journal of Arachnology 33(3): 776-784. ==> Abstract ==> PDF|
New Zealand's endemic sand dune Latrodectus widow spider species, L. katipo and L. atritus, possess behavioral and physiological attributes likely to promote dispersal over large distances. Morphological, physiological and behavioral similarities between L. katipo and L. hasselti, an Australian endemic, suggest gene flow may occur across the Tasman Sea. In this study we examine intraspecific and interspecific genetic relationships within the ND1 gene region between L. katipo, L. atritus, L. hasselti and L. hesperus to assess whether the genetic evidence supports current taxonomic species designations. We found low interspecific pairwise distances among L. katipo and L. atritus populations, suggesting either introgression, incomplete lineage sorting, or that the current taxonomic distinction between the two species may be invalid. Parsimony and maximum likelihood analyses were inconclusive as to the relationships between the New Zealand Latrodectus species and the Australian L. hasselti. Low pairwise distances between L. hasselti and the New Zealand widow fauna indicated that L. katipo and L. atritus were not present in New Zealand before the fragmentation of Gondwana.
Huber BA. 2005. Sexual selection research on spiders: progress and biases. Biological Reviews 80(3): 363–385. ==> Abstract ==> PDF|
The renaissance of interest in sexual selection during the last decades has fuelled an extraordinary increase of scientific papers on the subject in spiders. Research has focused both on the process of sexual selection itself, for example on the signals and various modalities involved, and on the patterns, that is the outcome of mate choice and competition depending on certain parameters. Sexual selection has most clearly been demonstrated in cases involving visual and acoustical signals but most spiders are myopic and mute, relying rather on vibrations, chemical and tactile stimuli. This review argues that research has been biased towards modalities that are relatively easily accessible to the human observer. Circumstantial and comparative evidence indicates that sexual selection working via substrate-borne vibrations and tactile as well as chemical stimuli may be common and widespread in spiders. Pattern-oriented research has focused on several phenomena for which spiders offer excellent model objects, like sexual size dimorphism, nuptial feeding, sexual cannibalism, and sperm competition. The accumulating evidence argues for a highly complex set of explanations for seemingly uniform patterns like size dimorphism and sexual cannibalism. Sexual selection appears involved as well as natural selection and mechanisms that are adaptive in other contexts only. Sperm competition has resulted in a plethora of morphological and behavioural adaptations, and simplistic models like those linking reproductive morphology with behaviour and sperm priority patterns in a straightforward way are being replaced by complex models involving an array of parameters. Male mating costs are increasingly being documented in spiders, and sexual selection by male mate choice is discussed as a potential result. Research on sexual selection in spiders has come a long way since Darwin, whose spider examples are reanalysed in the context of contemporary knowledge, but the same biases and methodological constraints have persisted almost unchanged through the current boom of research.
今井長兵衛. 2005. 日本における外来種問題. 生活衛生 49(4): 199-214. ==> PDF|
An alien species is defined as a species, subspecies or lower taxon occurring in a country or region outside that of its historically known range due to introduction by humans. Introduction can be either direct, as in the case of socio-economically valuable species that are imported, or indirect, as in the case of those that arrive accidentally together with imported goods and human immigrants. The term “invasive species” is given to alien species that, through predation, competitive substitution and gene contamination, adversely affect native biodiversity, the environment, agriculture, forestry, fisheries and human safety in the countries or regions to which they have newly immigrated. In Japan, the Invasive Alien Species Act was promulgated as of June 2, 2004, and went into force as of June 1, 2005. This article describes, first, factors affecting immigration, settlement and expansion of alien species, second, the present situation of recognized alien species in Japan and, third, countermeasures to be taken against alien species including invasive ones.
水野敏明，中井克樹，池田三郎. 2005.外来生物リスク問題に関する市民の認知と社会的ガバナンスへの要件. 社会技術研究論文集 3: 269-278. ==> PDF|
新海明，谷川明男. 2005. 文献による奈良県産クモ類目録. KISHIDAIA (東京蜘蛛談話会) 88: 90-105. ==> PDF|
...セアカゴケグモ 出典：92 著者不詳. 2005. セアカゴケグモ情報－奈良県生駒郡三郷町で発見．くものいと 37:18....
Snow LSE, Andrade MCB. 2005. Multiple sperm storage organs facilitate female control of paternity. Proceeding of the Royal Society B, DOI: 10.1098/rspb.2005.3088. ==> HTML Proc Biol Sci. 2005 Jun 7; 272(1568): 1139–1144. ==> PDF|
It has been proposed that multiple sperm storage organs (spermathecae) could allow polyandrous females to control paternity. There is little conclusive evidence for this since insemination of individual spermathecae is generally not experimentally manipulable. Here, we examined sperm use patterns in the Australian redback spider (Latrodectus hasselti), which has paired, independent spermathecae. We assessed paternity when two rivals were forced to inseminate a single storage organ or opposite storage organs. When males inseminated a single spermatheca, mean paternity of the female's first mate was 79.8% (median 89.4%), and 38% of first mates achieved 100% paternity. In contrast, when males inseminated opposite organs, the mean paternity of the first mate was 49.3% (median 49.9%), only 10% of males achieved complete precedence, and paternity was normally distributed, suggesting sperm mixing. Males responded to this difference by avoiding previously inseminated female reproductive tracts. Complete sperm precedence can only be achieved if females permit males to copulate with both reproductive tracts. Females often cannibalize smaller males during their first copulation, thus limiting their paternity to 50%. These data show that multiple sperm storage organs can increase female control of paternity.
|2005||[講演要旨] 佐竹宏康，吉田政弘，山下敏夫. 2005. B39 セアカゴケグモの防除について (Control of Latrodectus hasseltii). 衞生動物 56(Supplement): 74. ==> information→PDF|
|2005||谷川明男. 2005. 日本産クモ類目録 (2005年版). Kishidaia (東京蜘蛛談話会会誌) 87:127-187. ==> PDF|
|2005||[講演要旨] 吉田政弘，山下敏夫. 2005. 11 セアカゴケグモ の分布実態の解析 (11 Analysis of habitation chart of Latrodectus hasseltii). 衞生動物 (第 59 回日本衛生動物学会西日本支部大会講演要旨) (Proceedings of the 59th Annual meeting of Western Region) 56(2): 171. ==> information→PDF|
Garb JE, González A, Gillespie RG. 2004. The black widow spider genus Latrodectus (Araneae: Theridiidae): phylogeny, biogeography, and invasion history. Molecular Phylogenetics and Evolution 31(3): 1127–1142. (doi:10.1016/j.ympev.2003.10.012) ==> Abstract ==>PDF|
The spider genus Latrodectus includes the widely known black widows, notorious because of the extreme potency of their neurotoxic venom. The genus has a worldwide distribution and comprises 30 currently recognized species, the phylogenetic relationships of which were previously unknown. Several members of the genus are synanthropic, and are increasingly being detected in new localities, an occurrence attributed to human mediated movement. In particular, the nearly cosmopolitan range of the brown widow, Latrodectus geometricus, is a suspected consequence of human transport. Although the taxonomy of the genus has been examined repeatedly, the recognition of taxa within Latrodectus has long been considered problematic due to the difficulty associated with identifying morphological features exhibiting discrete geographic boundaries. This paper presents, to our knowledge, the first phylogenetic hypothesis for the Latrodectus genus and is generated from DNA sequences of the mitochondrial gene cytochrome c oxidase subunit I. We recover two well-supported reciprocally monophyletic clades within the genus: (1) the geometricus clade, consisting of Latrodectus rhodesiensis from Africa, and its is sister species, the cosmopolitan L. geometricus, and (2) the mactans clade containing all other Latrodectus species sampled, including taxa occurring in Africa, the Middle East, Iberian Peninsula, Australia, New Zealand, and North and South America. Recovery of the geometricus and mactans clades is consistent with previous designations of species groups within the genus based on female genitalic morphology. All L. geometricus sampled, consisting of specimens from Africa, Argentina, North America, and Hawaii, were recovered as a strongly supported monophyletic group with minimal amounts of genetic divergence, corroborating the hypothesis that human transport has recently expanded the range of this species.
Hung SW, Wang TL. 2004. Arachnid envenomation in Taiwan. Ann Disaster Med 3 Suppl 1: S12-S17. ==> PDF|
Taiwan is located at the juncture of tropical and subtropical regions. About 300 species of spiders in Taiwan are named. Among the variety of spiders, only two kinds of spiders are reported to do serious harm to people. They are Latrodectus hasselti (red back spider) and Macrothele species (include M. gigas, M. holsti and M. taiwanensis). Tarantula which is mainly imported for petting would also do harm to people. Until now, no mortality case after spider bite was reported in Taiwan. The treatments of spider bite in Taiwan are supportive treatments. It is important to educate people not to capture the spiders with hands and be aware of the spiders especially in the dark and wet environment. If bitten by a spider, it is important to search medical support as soon as possible.
|2004||石田誠良，西村平和，倉持隆. 2004. セアカゴケグモ等生息状況調査の結果について. 生活と環境 49(8): 61-64. ==> information only|
Kasumovic MM, Andrade MCB. 2004. Discrimination of airborne pheromones by mate-searching male western black widow spiders (Latrodectus hesperus): species- and population-specific responses. Canadian Journal of Zoology 82(7): 1027-1034. ==> PDF|
Males of many web-building spiders abandon their webs at maturity to search for a potential mate. Since wandering can be very risky, and females are often widely distributed, males should use any cues that might ensure rapid and accurate location of conspecific females. Although it has long been assumed that mate-searching male spiders locate females using species-specific airborne pheromones released from webs, few studies have experimentally examined this phenomenon in the field. Our results show that male western black widow spiders (Latrodectus hesperus Chamberlin and Ivie, 1935) are attracted to females' webs by an airborne cue released from the web, can distinguish between conspecific and heterospecific females, and can discriminate between webs produced by conspecific females from different geographical populations. The latter result demonstrates a partial premating block to fertilization between populations at the edges of the species range. Complementary interpopulation laboratory matings suggest that there may also be a postmating block to fertilization, as these copulations did not result in viable offspring. This study provides experimental field evidence of male attraction by airborne pheromones released from females' webs, shows the potential importance of these pheromones in species discrimination in black widow spiders, and suggests that northern and southern populations of L. hesperus may be incipient biological species.
Mito T, Uesugi T. 2004. Invasive alien species in Japan: the status quo and the new regulation for prevention of their adverse effects. Global Environmental Research 8(2): 171-191. ==> PDF|
A huge amount of alien species have been introduced into Japan and some have become ‘invasive,' having adverse effects on ecosystems, human safety, or agriculture, forestry and fisheries. Considering that the Japanese regulatory system has not dealt with the issue comprehensively, taking into account various suggestions from many entities concerned, and aiming to materialize the provisions of Article 8 (h) stipulated by the Convention on Biological Diversity, the Japanese Cabinet finalized a draft of the Invasive Alien Species Act and submitted it to the Japanese Diet (= Parliament) on March 10, 2004.
The framework consists of the following three main points:(1)Invasive Alien Species (IAS) shall be designated in the Cabinet Ordinance of the Act as having adverse effects on ecosystems, human safety, or agriculture, forestry and fisheries. Various actions dealing with IAS such as raising, planting, storing, carrying, and importing shall be prohibited in Japan with the exception of specified cases such as by obtaining permission from the competent ministers. (2) National/local governments, Non-Profit Organizations, and other entities concerned shall take appropriate measures to mitigate the impact of IAS that already exist in Japan. (3) Uncategorized Alien Species (UAS), which may possibly be categorized as IAS through detailed investigation, shall need detailed investigation by the Japanese government in order to be allowed to be imported into Japan. The period for determining categorization shall be within six months from requests by importers or exporters of UAS into Japan.
The Diet passed the draft and the new Invasive Alien Species Act was promulgated as of June 2, 2004. Following the establishment, the Japanese Cabined made a basic policy on October 15, 2004, for effective implementation of the Act. The Act shall be enforced within one year from its promulgation and IAS and UAS shall be designated before the enforcement based on suggestions by academic experts. Tens of IAS and thousands of UAS are expected to be designated in the first step.
Nihei, Naoko; Yoshida, Masahiro; Kaneta, Hiroyuki; Shimamura, Ryota; Kobayashi, Mutsuo. 2004. Analysis on the dispersal pattern of newly introducedLatrodectus hasseltii(Araneae: Theridiadae) in Japan by spider diagram. Journal of Medical Entomology 41(3): 269-276 (DOI: 10.1603/0022-2585-41.3.269) ==> HTML [PDF download可]|
The dispersal pattern of the widow spider Latrodectus hasseltii (Araneae: Theridiadae), in Osaka Prefecture, Japan, was analyzed from accumulated survey data of spider distribution. All confirmed infested points from 1996 to 2002 were plotted on a map, and infested points in each survey year were connected with the nearest previously confirmed points. Expansion patterns of the confirmed habitats were analyzed by year and dispersion distances were classified by using spider diagram, one of method of geographical information system spatial analysis. L. hasseltii moves by walking step by step on the ground, mainly in coastal areas during early stages of infestation, and also can be conveyed over distances by various vehicles, mainly in inland areas. These analyses show L. hasseltii does not move by ballooning.
|2004||Reed C. 2004. National and international frameworks for assessing biosecurity risks to New Zealand's indigenous biota: A case study on exotic spiders associated with table grapes from California. New Zealand Science Review 61(3-4): 69-72. ==> PDF|
Rowley SM, Raven RJ, McGraw EA. 2004. Wolbachia pipientis in Australian spiders. Current microbiology 49(3): 208-214 (DOI:10.1007/s00284-004-4346-z) ==> Abstract ==> PDF|
【Latrodectus hasseltii Redback: no infection】
Snow LSE, Andrade MCB. 2004. Pattern of sperm transfer in redback spiders: implications for sperm competition and male sacrifice. Behavioral Ecology 15(5): 785-792. (doi: 10.1093/beheco/arh080) ==> Abstract ==> HTML ==> PDF|
Many sperm competition studies have identified copulation duration as an important predictor of paternity. This result is often interpreted as a sperm transfer effect—it is assumed that sperm transfer is limited by copulation duration. Here we test the assumption of duration-dependent sperm transfer in the Australian redback spider, Latrodectus hasselti, in which a correlation between copulation duration and paternity has been implicated in the evolution of a rare male self-sacrifice behavior. Male redbacks facilitate sexual cannibalism by females during copulation. Sexual cannibalism is apparently adaptive for redback males, in part because it results in longer copulations (25 versus 11 min.), and copulation duration is positively correlated with paternity. We assessed sperm transfer in normal copulations and in copulations that we terminated at 5, 10, or 20 min. Our results show that the paternity advantage of sexual cannibalism is not owing to time-dependent sperm transfer, as redback males transfer the majority of their sperm within the first 5 min of copulation. This suggests that the link between copulation duration and paternity may instead be owing to cryptic female choice or the transfer of nongametic ejaculatory substances. Results further indicate that the act of cannibalism itself might play a role in mediating sperm transfer. This study highlights the importance of understanding mechanisms of sperm transfer when attempting to interpret the outcome of sperm competition studies.
|2004||[講演要旨] 吉田政弘. 2004. 51 セアカゴケグモの分布(2003年) (51 Ditribution of Latrodectus hasseltii). 衞生動物 55(Supplement), 57. ==> information→PDF|
|2004||[講演要旨] 吉田政弘. 2004. 9. セアカゴケグモの分散様式 (9.Dispersion of Latrodectus hasselti). 衞生動物 (58回日本衛生動物学会西日本支部大会講演要旨) (Proceedings of the 58th Annual Meeting of Western Region) 55(2): 148. ==> information→PDF|
Andrade MCB. 2003. Risky mate search and male self-sacrifice in redback spiders. Behavioral Ecology 14(4): 531-538. (doi: 10.1093/beheco/arg015) ==> Abstract ==> HTML ==> PDF|
Male redback spiders twist their abdomens onto the fangs of their mates during copulation and, if cannibalized (65% of matings), increase their paternity relative to males that are not cannibalized. The adaptive male sacrifice hypothesis proposes that this increased reproductive payoff from a single mating outweighs the residual reproductive value of a cannibalized male, because high mortality during mate searching restricts alternative mating opportunities. It has been reported that redback male residual reproductive value is low because males are functionally sterile after one mating—a putative intrinsic constraint that could arguably favor self-sacrifice in the absence of ecological restrictions on multiple mating. However, sterility and self-sacrifice may both arise as aspects of a terminal investment strategy if the probability of multiple mating is sufficiently low. Here I report field data that support the adaptive male sacrifice hypothesis. More than 80% of redback males die without finding a potential mate in nature. Data from two observational field studies and one release experiment suggest that in the absence of cannibalism, male redbacks would expect fewer than one mating opportunity in a lifetime. This expectation was not significantly higher for a large male or one in good condition. A simple quantitative analysis confirms that even if males are assumed to be fertile throughout life, the measured mortality rate during mate search in combination with previously documented paternity benefits of cannibalism is sufficient to ensure that self-sacrifice is adaptive for male redback spiders.
Berendonck B. 2003. Reproductive strategies in Latrodectus revivensis (Araneae: Theridiidae): functional morphology and sexual cannibalism. Doctoral Thesis, Heinrich-Heine-Universitat Dusseldorf, 219 pp. ==> PDF|
To reveal morphological and behavioural characteristics possibly involved in male and female reproductive strategies in Latrodectus revivensis, I investigated the functional morphology of male and female secondary genitalia (pedipalps and epigynum), using light-, scanning- and transmission electron microscopy. Additionally, I determined the female's remating probability in the field by counting and comparing the number of male embolus tips in the epigyna of females during different periods of their reproductive cycle. In laboratory matings, the frequency of cannibalism and related factors were recorded. Furthermore, courtship was analysed qualitatively. The experiments were complemented by literature surveys on the occurrence of mating plugs and cannibalism in Araneae.
直木秀夫, DAI L，中嶋暉躬. 2003. 昆虫毒と質量分析. Journal of the Mass Spectrometry Society of Japan
51(1): 91-95. ==> PDF|
The venom of scorpion and spider contain numerous neurotoxic compounds like proteins, peptides, and polyamine blocking to the glutamatergic neuromuscular transmission or acting on various types of ion channels. Such biological active compounds in the venom grand are used for offensive or defensive purposes to paralyze or prey on other insects. This diversity of compounds and actions provide a wealth of bioactive compounds that is a resource of neuroscience research and a source of novel pharmaceuticals. Among these studies mass spectrometry is used as one of the unique characterization method for such venom from the insect.
... .3 セアカゴケグモ...
Nihei N, Yoshida M, Kobayashi M, Kaneta H, Shimamura R, Agui N. 2003. Geographic information systems (GIS) analysis of the distribution of the redback spider Latrodectus hasseltii (Araneae: Theridiadae) in Osaka, Japan. Med. Entomol. Zool. 54(2):177-186 [二瓶直子, 吉田政弘, 小林睦生, 金田弘幸, 嶋村竜太, 安居院宣昭. 2003. GISによる大阪府におけるセアカゴケグモの分布解析. 衞生動物 54(2): 177-186] ==> Abstract and PDF|
Since the redback spider, Latrodectus hasseltii Thorell, was first confirmed in November 1995 in the Osaka Bay area in Japan and became established in high density in areas adjacent to the Kansai International Airport, its distribution range continues to expand. Based on the outcome of the redback spider surveys, we implemented address matching and tabulated the survey year, the address of confirmed infested sites and number of webs by year using GIS computer software and digital maps. We furthermore mapped the expanded areas of the spider infestation by year and address and produced density distribution maps for each year from 1995 to 2001 and a map for the period of the surveillance. In addition, since biting cases have been reported, we examined the relationship between the spider density and the number of biting cases. From our GIS analysis it became clear that the distribution range of the redback spider clearly continues to expand in Osaka Prefecture and the expansion of the spider occurred gradually in some coastal areas and dispersed from the densely distributed areas to the more inner areas in Osaka Prefecture. These analyses also show that the number of biting cases by the redback spider will increase in Osaka and surrounding prefectures infested with redback spiders.
|2003||[講演要旨] 二瓶直子，吉田政弘，小林睦生，金田弘幸，嶋村竜太. 2003. A18 GISによる地理的分布パターンから推測されるセアカゴケグモの拡散について (A18 Dispersion of the redback spider analyzed by geographic distribution patterns by GIS at Osaka Prefecture). 衞生動物 54(supplement): 30. ==> information→PDF|
Ohtsuka E, Dezaki K, Yamaguchi-Miyamoto T, Nojima H, Kamimura K, Yoshida M, Kuraishi Y. 2003. Algogenic and systemic effects of venom gland extract from the red back widow spider (Latrodectus hasseltii) in mice. Med. Entomol. Zool. 54(2): 161-167. [大塚英治，出崎克也，宮本(山口)朋美，野島浩史，上村清，吉田政弘，倉石 泰. 2003. セアカゴケグモ (Latrodectus hasseltii) の毒腺抽出物のマウスに対する発痛および全身性作用. 衞生動物 54(2), 161-167] ==> Abstract and PDF|
The algogenic effects of venom gland extract (VGE) from the red back widow spiders (Latrodectus hasseltii) and its component α-latrotoxin were investigated in mice. Mice were given an intraplantar injection of VGE or α-latrotoxin into the hind paw, and licking of the injected site was assessed as a pain-associated response. The VGE increased dose dependently the licking behavior at doses of 1/300th to 1/30th venom gland. The licking behavior elicited by an injection of VGE at a dose of 1/100th venom gland was significantly suppressed by subcutaneous pretreatment with the opioid analgesic morphine hydrochloride (3 and 10 mg/kg) but not the aspirin-like drugs, such as ketoprofen (10 and 30 mg/kg) and diclofenac sodium (10 and 30 mg/kg). An intraplantar injection of heat-treated VGE did not elicit licking behavior. An injection of α-latrotoxin (30 and 300 ng) markedly increased licking behavior. These findings suggest that an injection of VGE causes severe pain through non-inflammatory mechanisms. It is possible that the algogenic action of VGE is at least partly mediated by α-latrotoxin.
Segev O, Ziv M, Lubin Y. 2003. The male mating system in a desert widow spider. Journal of Arachnology 31(3):379-393. ==> Abstract ==> PDF|
Competition among males is a major force shaping sexual selection. We investigated the male mating strategy of the widow spider Latrodectus revivensis, a desert species with an annual life cycle. Based on morphology of the sperm storage organs reported for female Latrodectus, we predicted that males should guard sub-adult or virgin adult females. In a natural population, we found that males were generally monogamous, cohabiting longer with sub-adult females approaching the final molt than with adult females. Nevertheless, both the duration and timing of male cohabitation were highly variable. Males were found with females from a few days before or after female maturation to over two months after maturation. Maturation of males and females peaked in spring, with a second, smaller peak in summer. Adult males that matured in spring were larger than those maturing later in the summer, while for adult females the pattern was reversed. We suggest that large males of L. revivensis that mature in spring maximize reproductive success by mating with virgins. Late males will gain greater reproductive success from mating with large, late-maturing females, but the scarcity of these females in the population at this season may make opportunistic mating with non-virgin females a viable strategy.
|2003||吉田政弘. 2003. 日本における毒グモ咬症の今後の動向. 日本医事新報 (4155): 25-28. ==> information only|
|2003||[講演要旨] 吉田政弘. 2003. B10 セアカゴケグモの分布拡大と拡散 (B10 Distribution and diffusion of redback spider). 衞生動物 54(supplement): 37. ==> information→PDF|
吉田永祥，吉田政弘，岩上泰雄，瀧幾子，薗輝久，内野清子，田中智之. 2003. セアカゴケグモ Latrodectus hasseltii (Araneae: Theridiidae) 除去後の個体群動態. 衞生動物 54(4), 361-366. ==> Abstract and PDF|
An investigation on the recolonization and population dynamics of the Redback spider (Latrodectus hasseltii) was conducted bimonthly at a seaside park in Kaizuka City, Osaka, Japan, after all the spiders were completely removed from the study area in December 2000. The Redback spiders invaded again in February 2001, and their population density was recovered in December 2001. This study confirmed that breeding of Redback spiders began in June and continued until December.The minimum population observed in June was composed of only adult female individuals, while the maximum population found in December 2001 mainly consisted of larvae. The prolonged breeding might have caused the increase of population density and dispersal. The temperature measured ranged from -0.5℃ to 46.1℃ ; however. the Redback spider tolerated this harsh environment. This confirmed that the Redback spider, a tropical or subtropical species, is capable of colonizing even in the temperate area in Japan.
Andradef MCB, Banta EM. 2002. Value of male remating and functional sterility in redback spiders. Animal Behaviour 63(5): 857-870. ==> PDF|
In the Australian redback spider, Latrodectus hasselti, males typically use their paired copulatory organs (palps) to copulate twice with a single female then sacrifice themselves to their cannibalistic mates in a strategy that increases their paternity in that one mating, but leads to death. This type of terminal investment in one mating is predicted only if the expected value of future matings is low for males relative to the value of repeated mating with the same female. In this laboratory study, we quantified the reproductive value of mating more than once with the same female (repeated mating) and mating with more than one female (multiple mating) for male redback spiders. We tested two natural selection hypotheses for repeated mating, sperm limitation and reproductive insurance, but found no support for either hypothesis. We show that, in the absence of sperm competition or cannibalism, male lifetime reproductive output is the same whether a male copulates once, twice, or several times with a given female. Repeated mating does not increase the probability of successful fertilization, nor does it increase the number of offspring produced in successful matings. Although male repeated mating is not favoured because of increased fertility of mates, other studies suggest it may be important in sperm competition. Here we show that the relative reproductive value of the first two copulations is very high for redback males because they are functionally sterile after each palp has been used once; nonvirgin males are unable to father offspring. Functional sterility and repeated mating by male redbacks may be favoured by the same factors that lead to male sacrifice behaviour: ecological constraints on multiple mating combined with competitive benefits of maximal investment in the first mating.
Dondale CD. 2002. Black widow spiders: An outline of diversity. Biodiversity 3(1): 17-20. ==> Abstract 【本文，このサイトからは有料】|
Black widow spiders (Latrodectus species, Theridiidae), elicit fear, and fear is probably justified. Many deaths have been attributed to these spiders in the past, but antivenins have dropped the death rate substantially. Most bites are accidental, as when workers pick up the spiders while harvesting crops such as grapes. Persons who are bitten should seek medical attention at once. The intricate webs and potent venom of black widow spiders are primarily food-getting devices. The taxonomy of these spiders needs refining, and the exact number of species around the world (approximately 30) remains uncertain.
|2002||[講演要旨] 二瓶直子，吉田政弘，小林睦生，金田弘幸，嶋村竜太，高阪宏行，安居院 宣昭. 2002. B27 地理情報システムによる大阪府におけるセアカゴケグモの分布解析 (B27 Analysis of the distribution of red back spider in Osaka Prefecture by geographic information system). 衞生動物 53(Supplement): 62. ==> information→PDF|
Patrick B. 2002. Conservation status of the New Zealand red katipo spider ()Latrodectus katipo) Powell, 1871). SCIENCE FOR CONSERVATION 194, Department of Conservation, New Zealand. ==> PDF|
... Firstly, the slightly larger Australian redback (L. hasselti) has become established since the 1970s and is spreading in mainly dry inland areas of the South Island (Forster & Forster 1999). Figure 1. A female red katipo (Latrodectus katipo) from Karitane Peninsula, Otago. ...
|2002||[講演要旨] 吉田永祥，吉田政弘，滝幾子，岩上泰雄，内野清子. 2002. B29 Latrodectus hasseltii (セアカゴケグモ) 駆除後の個体群動態 (B29 The population dynamics of Latrodectus hasseltii after control in Osaka prefecture). 衞生動物 53(Supplement), 63. ==> information→PDF|
|2002||[講演要旨] 吉田永祥，岩上泰雄，内野清子，田中智之，吉田政弘，幸形 聡. 2002. 1. Latrodectus hasseltii (セアカゴケグモ) の個体数動態とその生息域の節足動物種との関係 (Comparative studies on the population dynamics of Latrodectus hasseitli and other Arthropods). 衞生動物 (第56回日本衛生動物学会西日本支部大会講演要旨) 53(2): 121. ==> information→PDF|
Griffiths JW. 2001. Web site characteristics, dispersal and species status of New Zealand's katipo spiders, Latrodectus katipo and L. atritus. Doctoral (PhD) Theses, Lincoln University. ==> Abstract ==> PDF|
Over the last 30 years, Latrodectus katipo Powell 1870 and L. atritus Urquhart 1890 numbers have declined and these species are now absent from many dune systems where they were once common. The cause of the decline in L. katipo and L. atritus numbers is not certain and little is known about their ecology. This thesis examined L. katipo and L. atritus web site characteristics, dispersal, species status and the probable implications of habitat modification on their ecology. The thesis focused on these aspects of L. katipo and L.atritus in order to provide information that might be used to conserve these species.
Results showed that L. katipo and L. atritus web sites are defined by similar characteristics. Both species were commonly found in Muehlenbeckia complexa A. Cunn., 1838, Coprosma acerosa A. Cunn., 1839, and Desmoschoenus spiralis (A. Rich.), but were also found in driftwood, Spinifex sericeus (R. Br. 1810) and Ammophila arenaria Link 1827. Web sites were most commonly associated with dune regions defined by 33-66 % ground cover, northerly, easterly or westerly aspect, sloping ground and the absence of detritus.
Using habitat classification trees, a model was constructed that was useful for predicting L. katipo and L. atritus presence and absence. The model accurately predicted L. katipo or L. atritus absence at > 90% of points sampled, but less accurately predicted L. katipo or L. atritus presence at 33 - 38 % of points sampled. It is argued that model was less able to predict L. katipo or L. atritus presence because intra-specific competition among the two species or inter-specific competition with Steatoda capensis Hann 1990 might prevent greater use of potential web sites in optimal habitat. Alternatively, the model may not accurately define web sites. This assertion is supported by results that suggest web sites might be associated with patches of open sand rather than ground cover per se and that the web site association with northerly, easterly or westerly aspect might be related to temperature rather than aspect.
The association between web sites and patches of open sand and northerly, easterly or westerly aspect was examined in the laboratory. Results showed that all catching-webs built by L. katipo and L. atritus were positioned over open sand and that no catching-webs were built within dense A. arenaria clumps. These results suggests the structural requirements of the catching-web are not met by dense dune grasses, which would explain why L. katipo and L. atritus are rarely present in dune regions dominated by dense A. arenari, or other dune grasses, such as Pennisetum clandeestinum Chiou 1903 and Stenotaphrum secundatum Kuntze 1891 that also have a dense growth habit. That the majority of spiders included in the experiment favoured web sites at the warmer well-lit end of a temperature and light gradient supported the hypothesis that the association between web sites and aspect may be linked to temperature.
L. katipo and L. atritus spiderlings were found to disperse by 'ballooning' and adult females are able to tolerate exposure to salt water for up to nine days, indicating that they may be capable of travelling substantial distances at sea on driftwood. These results suggest that both species are good dispersers, as evidenced by their current distributions, which span numerous geographic barriers, such as open sea, estuaries and large rivers. This assertion was further supported by molecular analysis that revealed low intra-specific pairwise distances between L. katipo and L. atritus populations in the ND1 gene region, indicating that intra-specific gene flow has recently occurred, and may still occur throughout the distributions of these species. Molecular analysis also revealed low inter-specific pairwise distances between L. hasselti and New Zealand's widow spiders suggesting that gene flow has recently occurred between the endemic Australian and New Zealand widow fauna and raises questions about the accuracy of their current taxonomy.
Overall, my results suggest that the likely cause of L. katipo and L. atritus decline is the increasing dominance of dense exotic dune grasses in New Zealand's coastal dune systems, as these do not appear to meet the structural requirements of either species' webs. Moreover, that L. katipo and L. atritus are rarely recorded from dunes modified by urban or rural development indicates that these types of development may also fail to provide suitable habitat for these species. Although results showed that L. katipo and L. atritus are good dispersers, the introduction of exotic plants and/or urban or rural development may result in the reduction and fragmentation of these species' habitat, inhibiting dispersal. This would reduce both species' capacity to re-colonise dune regions from which they have been displaced. Consequently, both species may be vulnerable to local extinction in areas where their habitat has been extensively modified.
Main BY. 2001. Historical ecology, responses to current ecological changes and conservation of Australian spiders. Journal of Insect Conservation 5(1): 9-25. (DOI:10.1023/A:1011337914457) ==> Abstract ==> PDF|
In response to geohistorical events from the Mesozoic through the Tertiary with contraction of mesic forest to southwestern and eastern montane and coastal regions, and expansion of woodlands and xeric shrublands, nobreak Australian spiders today comprise relict families and genera (confined to Gondwanan habitats and refuges) along with later evolved representatives which have adapted to changing environments. Tropical relicts also persist in refugia in the arid interior while some spiders (both mygalomorphs and araneomorphs) have adapted to arid conditions, mainly through specialized behaviours. Although fire has become increasingly a phenomenon of the Australian environment it is doubtful whether any spiders are adapted to fire per se. European settlement has impacted differentially on relictual and later evolved representatives; a few species, including the funnelweb (Atrax robustus) and redback spider (Latrodectus hasselti) have benefited through enhanced habitat opportunities and some species of Badumna and other genera have become synanthropic. It is suggested that conservation strategies need to consider the ecoevolutionary history of particular spiders and their natural vulnerability or resilience to environmental factors.
|2001||Manju S, Kumar D. 2001. Rare sighting of poisonous spider Latrodectus hasseltii indicus Simon (Araneae: Theridiidae) in a cotton field in Baroda district, Gujarat. Current Science 81(9): 1170-1171. ==> PDF 【草本根元に張った巣の絵あり】|
|2001||高岡諒，田伏久之. 2001. タランチュラ, セアカゴケグモ (特集 急性中毒--的確な治療のために)--(自然毒). 救急医学 25(2), 165-167. ==> information only|
|2001||[講演要旨] 吉田政弘. 2001. EB16 セアカゴケグモの分布 (EB16 Distribution of Latrodectus hasseltii). 衞生動物 52 (Supplement): 143. ==> information→PDF|
Berendonck B, Greven H. 2000. Morphology of female and male genitalia of Latrodectus revivensis Shulov, 1948 (Araneae, Theridiidae) with regard to sperm priority patterns. European arachnology 2000 (S. Toft & N. Scharff eds.), pp. 157-167. ==> PDF|
The shape of the female spermatheca is assumed to play a decisive role in determining the sperm priority patterns in spiders that probably are reflected in the mating behaviour of a given species. To estimate the significance of the shape of the female sperm storage organs with regard to sperm priority patterns and the possible influence of the broken embolus tip for subsequent males in Latrodectus revivensis we examined the morphology of virgin and mated females’ epigyna and male pedipalps by means of scanning electron- and light microscopy of cleared specimens. The female epigynal plate bears long mechanoreceptors. Her copulatory duct forms a narrow tube that takes up the male embolus during insertion. The spermatheca resembles the conduit type and first male sperm priority would be the expected pattern. However, the male embolus clearly shows a defined breaking point and its position inside the female spermathecal opening after copulation suggests that it might act as a mating plug by establishing a physical barrier against subsequent males.
Dias MFR, Brazil TK. 1999. Behavior and diet supply of Latrodectus group Mactans (Araneae, Theridiidae) in captivity. Revista Brasileira de Zoologia 16(4): 991-996. ==> PDF|
Lalrodeclus gr. maclans is responsible for 28% of all accidents provoked by spiders in state of Bahia, Brazil (1980-1990), which makes necessary the study of its manejament. The spiders were captured in Ondina, Salvador, and in Baxio, Esplanada (Bahia, Brazil); they were mantained in captivity, with food supply weekly (Alia sp., larva of Tenebrio sp. and Drosophila meganogaster) with three hours/ offers observation time, during march/95 to april/96. ln captivity, the spiders accepted two kinds of food: Alia sp., which seems to be the major item of its diet in natural conditions, and larva of Tenebrio sp., which is not available in natural conditions. Drosophila merogaster was systematically rejected. The feeding behavior is composed by four distinct steps: (1) immobilization, (2) inoculation, (3) second immobilization and (4) ingestion. Two kinds ofsocial alimentaly behavior are described. The results indicated that larvae of Tenebrio sp. can be an alternative supply for successfull maintenance of this species in captivity.
Kamimura K, Yoshida M, Nishio Y, Matsuse IT, Shimano S, Shirai Y. 1999. Overwintering of Latrodectus hasseltii in shelter traps in Osaka Prefecture. Med. Entomol. Zool. 50(2): 137-140. [上村清, 吉田政弘, 西尾恭好, 松瀬イネス倶子, 島野智之, 白井良和. 1999. 大阪府内における管トラップを用いたセアカゴケグモの越冬調査．衞生動物 50(2), 137-140] ==> Abstract and PDF|
|1999||菊屋奈良義. 1999. 有害動物対策の将来方向をさぐる: セアカゴケグモ事件の反省から (A Careful Consideration for the Future of Control of Harmful Insects and Animals, with a Reflection on a Big Confusion Caused by the Red-Backed Spider in Japan). 家屋害虫 21(1): 12-24. ==> information→PDF|
Matsuse IT, Kamimura K, Yoshida M. 1999. The tolerance of Latrodectus hasseltii (Araneae: Theridiidae) to low temperatures. Med. Entomol. Zool. 50(1): 71-73. [松瀬イネス倶子，上村清，吉田政弘. 1999. セアカゴケグモの耐寒性について. 衞生動物 50(1): 71-73] ==> Abstract and PDF|
大阪府下で採取したセアカゴケグモの耐寒性について調べた。成体および幼体を4∿-10.5℃の温度範囲下に置き, その生死を確認した結果, 耐寒性は齢期, 雌雄などで異なり, 雄成体が最も低温に強く, 本実験で約半数が-10℃において30分間耐えられた。2齢幼体がそれに次いで, ほぼ半数が20分強耐えられた。従って, 本種は北海道を含め, 日本における分布拡大の潜在能力を持っている。
Rocha Dias MF, Kobler T. 1999. Comportamento e padrão alimentar de uma espécie de Latrodectus do grupo Mactans (Araneae, Theridiidae) em cativeiro. [Behavior and diet supply of I>Latrodectus/I> group Mactans (Araneae, Theridiidae) in captivity] Revista Brasileira de Zoologia 16 (4): 991-996. ==> PDF|
Latrodectus gr. mactans is responsible for 28% of all accidents provoked by spiders in state of Bahia, Brazil (1980-1990), which makes necessary the study of its manej ament. The spiders were captured in Ondina, Salvador, and in Baxio, Esplanada (Bahia, Brazil); they were mantained in captivity, with food supply weekly (Atta sp., larva of Tenebrio sp. and Drosophila melanogaster) with three hours/ offers observation time, during march/95 to april/96. In captivity, the spiders accepted two kinds of food: Atta sp., which seems to be the major item of its diet in natural conditions, and larva of Tenebrio sp., which is not available in natural conditions. Drosophila melanogaster was systematically rejected. The feeding behavior is composed by four distinct steps: (1) immobilization, (2) inoculation, (3) second immobilization and (4) ingestion. Two kinds of social alimentary behavior are described. The results indicated that larvae of Tenebrio sp. can be an alternative supply for successful! maintenance of this specie in captivity.
KEY WORDS. Araneae, Theridiidae, Latrodectus, feed, diet, behavior
谷川明男・佐々木健志. 1999. 沖縄県産クモ類目録. Kishidaia (東京蜘蛛談話会会誌) 76:61-101. ==> PDF|
...ハイイロゴケグモ 北大東島,沖縄島; セアカゴケグモ 石垣島,西表島; クロゴケグモ 石垣島,西表島...
|1999||[講演要旨] 吉田政弘. 1999. B25 セアカゴケグモ の分布(1996～1998) (B25 Distribution of red back spider, Latrodectus hasseltii). 衞生動物 50(Supplement): 60. ==> information→PDF|
Andrade M. 1998. Female hunger can explain cariation in cannibalism despite male sacrifice in redback spiders. Behavioral Ecology 9(1): 33-42 (doi: 10.1093/beheco/9.1.33) ==> Abstract ==> PDF|
Male Australian redback spiders (Latrodectus hasselti Thorell: Theridiidae) place their abdomens directly over their mate's mouthparts during copulation, increasing the likelihood of sexual cannibalism. Male sacrifice may be adaptive because cannibalized males increase their paternity relative to those that are not eaten. Despite male sacrifice behavior, however, up to 50% of laboratory matings may end without sexual cannibalism. Here, I report a similar pattern in the field, where males were not cannibalized in 35% of observed matings (6/17). I examined variation in female cannibalistic behavior by evaluating the following three hypotheses for the occurrence of cannibalism from the female perspective: (1) the mistaken identify hypothesis proposes that females sometimes cannibalize males because they mistake them for prey, (2) the mate rejection hypothesis predicts that females cannibalize males who are unacceptable as mates, and (3) the feeding opportunism hypothesis predicts that hungry females are more likely to be cannibalistic. Field observations refuted the first two hypotheses: females recognized males as potential mates (i.e., nonprey), and cannibalized and noncannibalized males were not phenotypically different. The feeding opportunism hypothesis was supported. In staged field matings, cannibalistic females were hungrier than their noncannibalistic counter-parts. Moreover, a logistic regression analysis indicated that hunger was a significant predictor of cannibalism. Because redback males are below the typical prey size that females accept, well-fed females are less likely to consume their mates, despite the vulnerable mating posture. These results indicate that, although males facilitate sexual cannibalism, their fate may depend on the female's physical condition.
Keywords: feeding opportunism, female choice, food limitation, Latrodectus hasselti, male sacrifice, redback spider, sexual cannibalism, Theridiidae.
|1998||[講演要旨] 川合覚，小林睦生，吉田政弘，安居院宣昭，松田肇. 1998. 12 セアカゴケグモ の毒腺における微細構造とα-Latrotoxin の抗原局在性に関する研究 (Ultrastructural and Immunohistochemical studies on the venom gland of the red back spider). 衞生動物 49(2): 148. ==> information→PDF|
Kobayashi M, Sasaki T, Yoshida M, Muto A, Agui N. 1998. Reactivity of an antivenom against the red-back spider, Latrodectus hasseltii, to venom proteins of two other species of Latrodectus introduced to Japan. Med. Entomol. Zool. 49(4), 351-355. [小林睦生，佐々木年則，吉田政弘，武藤敦彦，安居院宣昭. 1998. 我が国に分布する他 2 種のゴケグモ毒腺タンパク質に対するセアカゴケグモ抗毒血清の反応性. 衞生動物 49(4), 351-355] ==> Abstract and PDF|
1995年に大阪で発見されたセアカゴケグモ以外にも横浜市, 那覇市などではハイイロゴケグモが, また, 八重山諸島には未だ分類が確立していないLatrodectus sp.(仮称ヤエヤマゴケグモ)が分布することが明らかになっている。セアカゴケグモの毒性は, マウスを用いた毒性試験およびオーストラリアでの咬症の報告から一般的に強いと考えられ, 我が国では全国4カ所にオーストラリアで製造されているセアカゴケグモ抗毒血清が突発的な咬症発生の対策上準備されている。しかし, この抗毒血清のセアカゴケグモ以外のゴケグモに対する治療効果は不明であり, 治療に使用が可能か否かの科学的根拠も明らかになっていない。そこで, ハイイロゴケグモとヤエヤマゴケグモ(仮称)の毒腺抽出物中のタンパク質と抗毒血清との反応性を調べた。その結果, セアカゴケグモの毒腺タンパク質に対して抗毒血清中のウマIgG抗体が強く結合し, ハイイロゴケグモの毒腺抽出物中のタンパク質のうちα-ラトロトキシンに対して若干弱い結合が認められた。ヤエヤマゴケグモの毒腺抽出物に対しては反応が弱いように見えたが, その結合の弱さはα-ラトロトキシンと考えられる110-120kD領域にみられるバンドのタンパク質量に起因していると考えられた。各々のゴケグモ種に対する抗毒血清が製造されていない現状を考えると, ヤエヤマゴケグモおよびハイイロゴケグモによる突発的な咬症による重症例において, 現在準備されているセアカゴケグモ抗毒血清を治療に使用できると考えられる。
夏原由博. 1996. セアカゴケグモの生態と刺咬症への対応. 生活衛生 40(1): 13-21. ==> PDF|
Ⅰ.セアカゴケグモ発見と対策の経過 1995年11月23日，大阪市立自然史博物館はセアカゴケグモが高石市で発見されたことを発表した. 大阪府は11月21日にその旨の報告を受け, 敏速に対応, 府のオーストラリア事務所を通じて抗毒素血清を緊急輸入するとともに
|1998||[講演要旨] 西尾恭好，福永昭廣，吉田永祥. 1998. 7 セアカゴケグモの後胚発生について (Postembryonic development of red back spider). 衞生動物 49(2): 156. ==> information→PDF|
|1998||[講演要旨] 大利昌久(Ori Masahisa). 1998. セアカゴケグモを中心としたクモ咬症と病害 (Widow Spider Venoms and Spider Toxins). 衞生動物 49(2): 145. ==> information→PDF|
|1998||[講演要旨] 上村清，松瀬倶子，島野智之，白井良和，吉田政弘，西尾恭好. 1998. 8 日本に上陸したセアカゴケグモについて (7) 耐寒性試験と冬期における生息状況 (The redback spider in Japan (7) On the cold). 衞生動物 49(2): 156. ==> information→PDF|
|1998||吉田政弘. 1998. セアカゴケグモの分布と生態. セアカゴケグモの調査報告書，1-13，大阪府立公衆衛生研究所|
|1997||[講演要旨] 出崎克也(Dezaki K.)，倉石泰，上村清，松瀬倶子，吉田政弘. 1997. B35 日本に上陸したセアカゴケグモについて (6):毒腺抽出物の発痛作用 (B35 Latrodectus hasseltii landed in Japan (6): The toxicity of venom gland-extract). 衞生動物(日本衛生動物学会) 48(Supplement): 56. ==> information→PDF|
|1997||Horton P. 1997. Redback spider is now established in Japan: bites can be recognised by a unique sign. BMJ: British Medical Journal 314(7092): 1484. ＜Letter形式＞ ==> PDF|
|1997||[講演要旨] 上村清，吉田政弘，松瀬倶子．1997. B34 日本に上陸したセアカゴケグモについて (5):管トラップ調査 (B34 Latrodectus hasseltii landed in Japan (5) : Field examination). 衞生動物(日本衛生動物学会) 48(Supplement): 55. ==> information→PDF|
|1997||[講演要旨] 川合覚，小林睦生，吉田政弘，松田肇，安居院宣昭. 1997. 11 セアカゴケグモの毒腺に関する微細構造の観察 (11 Ultrastructure of the venom gland of the red back). 衞生動物 48(2): 162. ==> information→PDF|
|1997||[講演要旨] 小林睦生，平岡毅，吉田政弘，安居院宣昭. 1997. 12 セアカゴケグモのマウスへの直接刺咬と排出毒量について (Effect of biting of red back spider on mice and the amount of venom protein expelled from venom glands). 衞生動物 48(2): 162. ==> information→PDF|
|1997||[講演要旨] 小林睦生，平岡毅，吉田政弘，貞弘省二，安居院宣昭. 1997. B33 セアカゴケグモ毒腺抽出物のマウス腹腔内および皮下接種による毒性の違いについて (Differences in toxicity of venom gland extract of red back spiders between intraperitoneal and subcutaneous injection to mice). 衞生動物 48(Supplement): 55. ==> information→PDF|
|1997||[講演要旨] 楠本倶子，上村清，荒木克昌，吉田政弘. 1997. 1 日本に上陸したセアカゴケグモ について:(3) 飼育成績. 衞生動物 48(2): 169. ==> information→PDF|
松瀬イネス倶子，武田カチア美知枝，上村清，吉田政弘. 1997. 日本に侵入したセアカゴケグモの低温適応性. 衞生動物 48(2), 117-122. [Matsuse IT, Takeda CM, Kamimura K, Yoshida M. 1997. Tolerance of Latrodectus hasseltii (Araneae: Theridiidae) to low temperatures in Japan. Medical Entomology and Zoology 48(2): 117-122] ==> Abstract and PDF|
セアカゴケグモは1995年9月に大阪府の高石市で発見され, 大阪湾沿岸地帯, 三重県四日市市などでも生息が確認された。また1996年3月上旬の現地調査ではセアカゴケグモの越冬が確認され, 春夏秋冬のいずれの調査において成成虫, 若虫, 卵嚢のいずれもが採集できた。採集したクモと卵嚢は研究室に持ち帰り, 25℃, 60% RH, 14時間照明で, 50ml容量のガラス瓶内で, ショウジョウバエを餌とし, 個別飼育を行った。その内, 卵嚢より脱出した若虫を用いて, セアカゴケグモが寒冷期に, 冬期と同様の低温条件下の飼育によって生存できるかどうかを検討した。その結果, 5℃においては最長47日間生存し, 10℃及び15℃ではそれぞれ175及び270日生存した。この間の発育零点は15℃前後であった。セアカゴケグモを含むゴケグモ類が日本に分布していなかった主因は気温によるものと推定されているが, 飼育実験の結果, セアカゴケグモは日本に定着し, さらにより広範囲に広がる可能性があることが示唆された。
永田健二，新庄五朗，奥田寿男，吉田政弘. 1997. 各種殺虫剤の セアカゴケグモ Latrodectus hasseltii に対する殺虫効力. 衞生動物 48(2): 135-139. [Nagata K, Shinjo G, Okuda H, Yoshida M. 1997. Efficacy of several insecticides to red-back widow spiders, Latrodectus hasseltii, collected in Osaka and Mie Prefectures, Japan. Medical Entomology and Zoology 48(2): 135-139] ==> Abstract and PDF|
Lethal and knockdown effects of several insecticides to red-back widow spiders, Latrodectus hasseltii, were evaluated. Spiders were collected three times in Osaka and Mie Prefectures, Japan, in 1995 and 1996. In the continuous contact method on glass pot and the topical application method, permethrin and phenothrin were most effective among the tested insecticides. Knockdown and lethal effects by spraying with commercial insecticide aerosols, containing pyrethroids, were sufficient in the case of direct spraying without the web, but the effects decreased in the case of spraying through the web.
|1997||下出英明，成隆光，相良武彦. 1997. セアカゴケグモ駆除報告. 環境管理技術 15(5): 265-272. ==> information only|
|1997||[講演要旨] 吉田永祥, 西谷謙二, 米本申一, 福永昭廣, 西尾恭好. 1997. 2 Latrodectus hasseltii の産卵状態について. 衞生動物 48(2): 169. ==> information→PDF|
Andrade MCB. 1996. Sexual selection for male sacrifice in redback spiders. Science. 271: 70-72. ==> Abstract ==> PDF|
During copulation, male redback spiders (Latrodectus hasselti: Theridiidae) position themselves above the female's jaws. This apparent male complicity in sexual cannibalism is favored by sexual selection because cannibalized spiders receive two paternity advantages. First, cannibalized males copulated longer and fertilized more eggs than those that survived copulation. Second, females were more likely to reject subsequent suitors after consuming their first mate. These results represent empirical evidence for male copulatory suicide as an adaptive behavior.
Hiraoka T, Kobayashi M, Sadahiro S, Agui N. 1996. Protein components and toxicity of venom gland-extract in the red back widow spiders, Latrodectus hasseltii collected in Osaka-City, Japan. Med.Entomol.Zoo1. 47(3): 273-280. [平岡毅，小林睦生，貞弘省二，安居院宣昭. 1996. セアカゴケグモ毒腺抽出物のタンパク質成分とマウスに対する毒性について. 衞生動物 47(3): 273-280] ==> Abstract and PDF|
セアカゴケグモの毒腺抽出物をSDS-ポリアクリルアミド電気泳動法によって分析した。その結果, 低分子領域(20kD以下)から高分子領域(200kD以上)まで多数のバンドが認められた。分子量110-120kDに主要なバンドが認められ, また, 45kD付近にも複数の濃いバンドが見られた。オーストラリアより生きたまま輸入されたセアカゴケグモと大阪産のゴケグモのタンパク質パターンを比べたところ, 非常に類似していた。オーストラリアより凍結乾燥されて輸入された毒腺抽出物の電気泳動パターンは110-120kDの主要なバンドが明らかに弱くなり, 分子量約77kD付近に新たなバンドが出現した。ジュウサンボシゴケグモの分子量130kDのα-latrotoxinに対する単クローン抗体は110-120kDのバンドと45kD付近のバンドを強く認識した。また, 凍結乾燥毒の約77kDのバンドも強く認識したことから, このバンドはα-latrotoxinの分解産物である可能性が強く示唆された。横浜産ハイイロゴケグモの毒腺抽出物でも, 110-120kDと45kD付近のバンドが強く単クローン抗体に認識された。大阪産セアカゴケグモ1匹分の毒腺抽出物を腹腔内に注射された雄マウス(ddY系統)は2日以内に7匹全て死亡したが, 輸入された凍結乾燥毒はマウスに対して若干弱い毒性を示した。また, 毒腺抽出物を注射された全てのマウスは毒量に関係なく明らかな体重減少を示した。以上の結果から, 大阪産のセアカゴケグモには明らかにα-latrotoxinが存在すること, また, マウスに対する毒性は既報の結果とほぼ変わらないことが示された。
|1996||[講演要旨] 上村清，楠本イネス倶子，武田カチア味知枝，吉田政弘，丸山勝巳. 1996. 132 日本に上陸した セアカゴケグモ について:(1) 冬期における生息状況 (132 Latrodectus mactans hasselti landed in Japan : (1) The situation in the winter). 衞生動物 47(Supplement): 62. ==> information→PDF|
|1996||[講演要旨] 木村明生，弓指孝博，吉田政弘，中村央，奥野良信. 1996. 大阪で捕獲されたセアカゴケグモ毒腺蛋白質の解析結果について. 日本公衆衛生学会総会抄録集 55(3): 613. ==> information only|
|1996||北角彰. 1996. オ-ストラリア「セアカゴケグモ 事情」-1. 生活と環境 41(8): 97-102. ==> information only|
|1996||北角彰. 1996. オ-ストラリア「セアカゴケグモ事情」-3- セアカゴケグモ の生態と毒性. 生活と環境 41(10): 73-80. ==> information only|
|1996||北角彰. 1996. オ-ストラリア「セアカゴケグモ 事情」(4). 生活と環境 41(11): 71-75. ==> information only|
|1996||北角彰. 1996. オ-ストラリア「セアカゴケグモ 事情」-5. 生活と環境 41(12): 77-81. ==> information only|
|1996||[講演要旨] 楠本イネス倶子，武田カチア味知枝，上村清，吉田政弘. 1996. 133 日本に上陸した セアカゴケグモ について:(2) 低温下における飼育成績 (133 Latrodectus mactans hasselti landed in Japan : (2) Breeding at low temperature). 衞生動物 47(Supplement): 64. ==> information→PDF|
夏原由博. 1996. セアカゴケグモの生態と刺咬症への対応 (Ecology and Clinical Toxicology of the Widow Spiders, Latrodectus mactans hasselti and L. geometricus). 生活衛生 40(1): 13-21. ==> PDF|
夏原由博. 1996. 地球化時代の都市と自然. 生活衛生 40(5): 300-305. ==> PDF|
... 1995年末のセアカゴケグモ の発見はマスコミで大き ...
|1996||西川喜朗，金沢至. 1996. セアカゴケグモの発見とその毒性に対する対策 (Discovery of Latrodectus Species From Japan and Countermeasure to Their Venoms). 環動昆 7(4): 214-223. ==> information only|
|1996||[講演要旨] 西村平和，吉田政弘，北角彰，冨永修. 1996. 泉大津保健所管内のセアカゴケグモ分布と駆除対策. 日本公衆衛生学会総会抄録集 55(3): 612. ==> information only|
|1996||小野展嗣. 1996. セアカゴケグモ--オ-ストラリアからの招かれざる客. インセクタリゥム 33(7): 192-200. ==> information only|
大利昌久，新海栄一，池田博明. 1996. 日本へのゴケグモ類の侵入. 衞生動物 47(2), 111-119 [Ori M, Shinkai E, Ikeda H. 1996. Introduction of widow spiders into Japan. Med.Entomol.Zool. 47(2), 111-119] ==> Abstract and PDF|
The redback spider, Latrodectus hasseltii, is a common venomous spider in Australia. This species had not been recorded in Japan until late 1995. Large numbers of redback spiders were collected in Osaka City and in Yokkaichi City, Mie Prefecture, in November 1995. Another species of widow spiders, namely, the brown widow spider L. geometricus, was also collected in various ports : Yokohama, Tokyo, Nagoya, Osaka and in Okinawa. The author has reviewed current available information on widow spiders including the life cycle, reproduction, hunting behavior, systematics and distribution of each species, etc. The invasion route of these species into Japan is also discussed. The invasion of redback spiders into Japan apparently dates back several years as frequently old, empty egg sacs have been found. There is no information on how the redback spiders survived the winter season in Japan. Fortunately, so far in Japan no biting cases have been reported.
|1996||大利昌久，新海栄一，池田博明. 1996. セアカゴケグモについての考察. 日本医師会雑誌 115(10): 1741-1749. ==> information only|
大利昌久・新海栄一・池田博明. 1996. 日本へのゴケグモ類の侵入. 衞生動物 47(2): 111-119 [Ori M, Shinkai E, Ikeda H. 1996.Introduction of widow spiders into Japan. Medical Entomology and Zoology 47(2), 111-119] ==> information→PDF|
The redback spider, Latrodectus hasseltii, is a common venomous spider in Austraiia． This species had not been recorded in Japan until late l995. Large numbers of redback spidefs were collected in Osaka City and in Yokkaichi City, Mie Prefecture, in November 1995, Another species of widow spiders, namely, the brown widow spider L. geometricus, was also collected in various ports; Yokohama, Tokyo, Nagoya, Osaka and in Okinawa. The author has reviewed current available information on widow spiders including the life cycle, reproduction, hunting behavior, systematics and distribution of each species, etc. The invasion route of these species into Japan is also discussed. The invasion of redback spiders into Japan apparently dates back several years as frequently old, empty egg sacs have been found. There is no information on how the redback spiders survived the winter season in Japan. Fortunately, so far in Japan no biting cases have been reported.
Tanaka K, Watanabe M. 1996. Influence of Prey Species on the Supercooling Ability of the Redback Spider, Latrodectus hasseltii (Araneae: Theridiidae). Acta Arachnologica (Arachnological Society of Eastern Asia) 45(2): 147-150. [田中一裕, 渡辺匡彦. 1996. セアカゴケグモの過冷却点に及ぼす餌種の影響. Acta Arachnologica 45(2): 147-150] ==> PDF|
セアカゴケグモの過冷却点(SCP)は餌種によって異なった. このことは消化管内容物が何らかの形でクモのSCPに影響することを示唆している. 餌種とクモの過冷却点の比較から, 餌種のクモの過冷却点に対する効果の違いは, 餌種体内の氷核活性物質(INAs)の有無だけでなく, その質や取り込まれやすさの違いに起因していることが示唆された.
|1996||Tu AT. 1996. セアカゴケグモ その毒の正体は何か? 化学 51(2), 101-104. ==> information only|
|1996||[講演要旨] 吉田政弘，西村平和，富永修，北角彰. 1996. 日本におけるセアカゴケグモの分布とそのひそみ場所. 日本公衆衛生学会総会抄録集 55(3): 614. ==> information only|
|1995||Forster L. 1995. The behavioural ecology of Latrodectus hasselti (Thorell), the Australian redback spider (Araneae: Theridiidae): a review. Rec. West. Aust. Mus. Suppl. 52 (Australian spiders and their relatives): 13-24. ==> 有料($10.00)|
|1995||西川喜朗. 1995. セアカゴケグモとはどんなクモか? Acta Arachnologica (日本蜘蛛学会) 44(2): 205-208 ??? ==> information only|
小野展嗣. 1995. 日本におけるハイイロゴケグモ (クモ目:ヒメグモ科) の記録（英文）. Acta Arachnologica (日本蜘蛛学会) 44(2):159-166. ==> PDF|
ハイイロゴケグモ (Latrodectus geometricus) (ヒメグモ科) を日本から初めて記録した. 横浜港のコンテナ埠頭に隣接する人工的な公園において, 冬期に数個体の卵のうをもった♀および多数の幼生が採集された. 他の研究者の私信によれば, 同種のクモが主要な貿易港である東京, 名古屋, 大阪および浦添市などの港湾地域でも発見されている.
Forster LM. 1992. The Stereotyped Behavior of Sexual Cannibalism in Latrodectus-Hasselti Thorell (Araneae, Theridiidae), the Australian Redback Spider. Australian Journal of Zoology 40(1): 1-11. ==> Abstract 【本文，このサイトからは有料】|
This paper presents the first account of stereotyped behaviour in the practice of sexual cannibalism in any species. Cannibalism is achieved by female Latrodectus hasselti spiders, primarily because the copulatory orientation of the male in this species is unique and does not conform to the orthodox posture of males of other Latrodectus species. In this case, after penetration of the epigynum with one palpal embolus, the male turns a somersault through 180-degrees so that his abdomen comes to rest against the female's mouthparts, whereupon she begins to devour him. The cannibalistic process is slow and the male often succeeds in a second intromission with the other palp. The somersault is highly stereo-typed and predictable; it was observed in all 56 intromissions in the present study. The nuptial death risk to the male during copulation if both palps are employed is 0.66. However, even if he escapes copulatory demise he will die from his injuries within two days. Male Latrodectus hasselti can be mated with female L. katipo, an allopatric species native to New Zealand. Somersaulting by the male L. hasselti also occurs in this inter-specific copulation but the female L. katipo makes no attempt to devour him. It is concluded that male somersaults and female cannibalistic behaviour in L. hasselti are genetically programmed events.
Schmidt G. 1991. Further crossing experiments in Latrodectus species (Araneida: Theridiidae). Bull. Soc. Nauchâtel. Sci. Nat. 116(1): 215-222. ==> PDF|
In continuation of earlier tests, crossing experiments were performed with the following species: Latrodectus lugubris (Dufour,1820), Kazakhstan, L. tredecimguttatus (Rossi,1790), Corsica, L. hesperus Chamberlin & Ivie,1935, California, L. geometricus C. L. Koch,1841, South Africa, Argentina, L. g. obscurior Dahl1902, Madagascar, and L. hasselti Thorell,1870, Australia.
Variably, large males of L.13-guttatus did not copulate with a female of L. lugubris, whereas a small male of L. fcesperus mated with this female on the 18th day of the trial. The male of L. lugubris did not copulate with females of L. geometricus (Argentina) and L. hasselti. However, a very intensive courtship behaviour could be observed with females of these species. Males of L. geometricus did not copulate with females of L. g. obscurior. The male of L. hesperus did not react on females of L. geometricus and L. g. obscurior. A female of L. g. obscurior which had killed a male of L. geometricus before, copulated totally unexpectedly with a large male of L. 13-guttatus. This male and several other males of this species did not react to females of L. geometricus. or only weak to females of L. hesperus. There was no reaction between males of L. geometricus and females of L. hesperus and L lugubris, but a very intensive courtship of the male of L. lugubris in front of a female of L. hesperus. One day later the male was found dead and wrapped (after copulation?). The female of L. hesperus constructed an egg-sac with infertile eggs. After the successful matings between L. hesperus x L. lugubris and L.13-guttatus x L. g. obscurior no egg laying occurred however.
Hann SW. 1990. Evidence for the displacement of an endemic New Zealand spider, Latrodectus katipo Powell by the South African species Steatoda capensis Hann (Araneae: Theridiidae). New Zealand Journal of Zoology 17: 295-307. ==> PDF|
The competitive interactions between Latrodectus katipo and Steatoda capensis were studied under the hypothesis that L. katipo is being displaced from its natural habitat by competition from S. capensis. Use of trophic andspatialresources were studied. High overlap for both resources was found. Data on reproductive potential revealed that S. capenisis has a significantly higher reproductive output. Laboratory predation experiments indicated L. katipo adults are not inferior to S. capensis. Evidence suggesting displacement following L. katipo population crashes was obtained. Differences in reproductive potential and seasonal reproduction are proposed as the mechanism underlying the displacement.
Raven RJ. 1990. Spider predators of reptiles and amphibia. Memoirs of the Queensland Museum 29(2): 44. ==> Abstract 【本文は有料】|
The predation of reptiles and amphibians by spiders in Australia is briefly discussed. The author has observed the wolf spider (Lycosa lapidosa) preying on the frog Litoria lesueuri, and red-back spiders (Latrodectus hasseltii) on the skinks Cryptobelpharus virgatus and Anomalopus verreauxii.
|1990||Schmidt G. 1990. Courtship behaviour, copulation and crossing experiments in Latrodectus species (Araneida: Theridiidae). Acta Zool. Fenn 190: 351-355.|
Forster LM, Kavale J. 1989. Effects of food deprivation on Latrodectus hasselti Thorell (Araneae: Theridiidae), the Australian redback spider. New Zealand Journal of Zoology 16(3): 401-408. ==> Abstract ==> PDF|
Food deprivation tests indicate that most sub-adult and adult female Latrodectus hasselti spiders would be able to endure long periods of starvation if incarcerated in cargo. The data show that, under appropriate conditions, sub-adults survive for up to 160 days and some adults for more that 300 days. Temperature is an important variable with longevity being greatest at 10°C and markedly reduced at 25°C. Sluggishness is more pronounced at lower temperatures and probably reflects reduced metabolic rates. Even after 2–3 months without food, most spiders recover when fed.
Five stages mark the progress of starvation (Indices of Starvation) and reflect a gradual decline in the spider’s normal functions. As the abdomen shrinks, with a concomitant loss of hydraulic pressure, there is a gradual decline in web-building and locomotory activities which ultimately end in the spider’s death. It is assumed that nutritional deficiency and, to a lesser extent, dehydration contribute to mortality.
Downes MF. 1987. Postembryonic development of Latrodectus hasselti Thorell (Araneae, Theridiidae). Journal of arachnology 14: 293-301. ==> PDF|
In northern Queensland the eggs of Latrodectus hasselti have a lower developmental temperature threshold than do postembryos which in turn have a lower threshold than first instar spiderlings prior to emergence from the egg sac. Emerged spiderlings, however, develop normally at temperatures below that which would prevent emergence from the egg sac. Arrested development of free-living first instar spiderlings may require a temperature of 10°C or less (Forster 1984). The subsequent stadia for both sexes are in general shorter than for the American species of Latrodectus which mature later and live longer than L. hasselti. For all species of Latrodectus for which temperature-controlled data are available males have consistently longer early stadia than do females, partly compensating for an asynchrony in time to maturity. L. hasselti males usually matured in the fourth instar, females in the sixth.
|1986||森谷清樹. 1986. 日本の有毒節足動物. 化学と生物 24(9): 618-624. ==> PDF|
Austin AD. 1985. The function of spider egg sacs in relation to parasitoids and predators, with special reference to the Australian fauna. Journal of Natural History 19(2): 359-376. ==> Abstract 【本文，このサイトからは有料】|
The function of spider egg sacs is analysed as structures to reduce or prevent mortality by parasitoids and predators. The host relationships of the groups concerned are documented, with special reference to the Australian fauna. Many new records are presented and the biology of each group is discussed. Information presented supports the hypothesis that egg sacs are an effective barrier against scavenging predators (generalists), while coevolution between spiders and their specialized (highly adapted) parasitoids and predators is responsible for the specificity displayed by the latter two groups and the structural diversity evident of egg sacs.
Downe MF. 1985. Fecundity and fertility in Latrodectus hasselti (Araneae: Theridiidae). Australian Journal of Ecology 10(3): 261–264. ==> Abstract ==> PDF|
A total of 216 egg sacs of Latrodectus hasselti Thorell was examined to determine the proportion of infertile or otherwise inviable eggs. This proportion varied greatly between egg sacs but there was no consistent trend towards an increase or decrease in fecundity or fertility in sequences of egg sacs produced by given female spiders. It is suggested that the production of inviable eggs, by providing an early food source, may enable spiderlings to escape from unfavourable areas.
|1984||Downes MF. 1984. Egg sac'theft'among Latrodectus hasselti females (Araneae, Theridiidae). The Journal of Arachnology (USA) 12(2): 244. ==> PDF|
Forster LM. 1984. The Australian redback spider (Latrodectus hasselti): its introduction and potential for establishment and distribution in New Zealand. pp. 273-289. Laird M ed. Commerce and the spread of pests and disease vectors (Pacific Science Congress 15th, 1983, Dunedin, N.Z.), New York : Praeger, 1984. 354 pp. ==> PDF 【本文，このサイトからは有料】 ==> book information|
At least 36 individuals of Latrodectus hasselti were intercepted in New Zealand in 1966-82, all from goods being brought into the country from Australia. In addition, 3 females were discovered in the Otago region, giving rise to the possibility that they might be established there. The results of a series of experiments aimed at determining whether the spiders could survive in central Otago are presented. The effects of different temperatures on developmental times, humidity requirements, habitat preferences, dispersal and reproductive behaviour were examined. The studies suggested that the spiders could become dispersed throughout New Zealand by wind, but that their survivorship would depend largely on the availability of arid habitats, as well as the suitability of summer temperatures for breeding and appropriate conditions for overwintering.
Forster L, Kingsford S. 1983. A preliminary study of development in two Latrodectus species (Araneae: Theridiidae). New Zealand Entomologist 7(4): 431-439. ==> Abstract ==> PDF|
Young spiders of two New Zealand Latrodectus species were reared to maturity. Considerable variability in growth rate, instar length, relative size, colouration, and patterning was observed both intraspecifically and interspecifically. In general, successive instars increased in length. In both species males matured in 4 moults and lived for only 4-10 weeks, whereas females matured in 6 moults and often lived for 2 years.
大利昌久. 1975. クモ刺咬症の10例について. 衞生動物 26(2-3): 83-87. [Ori M. Ten human cases of spider bite] ==> PDF|
1954年から1974年の過去20年間に著者が経験した5種のクモによる10症例の刺咬症を報告した。その他既報例を合わせ9種のクモによる16症例について, クモ刺咬症の発症時期, 発症原因, 被害患者の性, 年代, 病害の程度, 治療の問題点を明らかにした。5月から8月の暖かい季節に発症し, クモを直接手で捕えようとする瞬間に受傷するのが多く, 刺咬部は四肢, とくに上肢に多い。受傷患者は10代に多く, ほとんど男性であった。全症例を病害の程度に従って無症状, 軽症, 中等症, 重症の4つに分類したが, 重症例はセアカゴケグモとカバキコマチグモの2種であった。クモ刺咬部の治療上とくに問題になったのは, 受傷後も持続する耐えがたい痛みに対する治療法で, 一般の視床, 脊髄性鎮痛剤では著効をえられなかったことである。本邦において今迄に報告されたクモ刺咬症についても考察を行った。
Eason RR, Peck WB, Whitcomb WH. 1967. Notes on spider parasites, including a reference list. Journal of the Kansas Entomological Society 40(3): 422-434. ==> TopPage preview （無料メンバー登録必要）|
Twenty-seven instances of parasitism were recorded among 1,679 spiders kept in the laboratory for various periods of time over a three-year study. Five species of Ogcodes, one Acrocera, one Gelis, one Acoloides, and one Idris, many of them new records, were found as parasites of several species of lycosids or of Oxyopes salticus (Hentz). The total incidence of parasitism was 1.6%. Aspects of behavior and the life cycle are given for four species of Ogcodes and for Idris and Gelis. A reference list and bibliography of parasitism in spiders is included
|1962||Abalos JW. 1962. The egg-sac in the identification of species of Latrodectus (Black-Widow spiders). Psyche: A Journal of Entomology 69.4: 268-270.|
|1961||Daniel JC., and Soman PW. 1961. Observations on the spider Latrodectus hasseltii indicus Simon with a note on arachnidism. Journal of the Bombay Natural History Society 58.3 : 823-826.|
|1959||Levi HW. 1959. The spider genus Latrodectus (Araneae, Theridiidae). Transactions of the American Microscopical Society 78(1): 7-43. ==> TopPage preview （分類記載，無料メンバー登録必要）|
|1959||Shulov A, Weissman A. 1959. Notes on the life habits and potency of the venom of the three Latrodectus spider species of Israel. Ecology 40(3): 515-518. ==> TopPage preview ==> PDF (但し前の論文の続きで)|
Rempel JG. 1957. The embryology of the black widow spider, Latrodectus mactans (Fabr.). Canadian Journal of Zoology 35(1): 35-74. ==> Abstract 【本文有料】|
The embryonic development of Latrodectus mactans, the black widow spider, from the time the egg is laid until the embryo is ready to emerge is described and an attempt made to correlate the internal developmental changes with changes in external body form. In agreement with observations of early students of spider embryology it is found that vitellocytes give rise to the mesenteron and hence the yolk cells are considered as the entoderm. The first blood cells are derived from extraembryonic cells, and are therefore ectodermal. A theory of head segmentation is suggested that contrasts with commonly accepted theories of arthropod segmentation by postulating that the spider brain is a syncerebrum made up of a protocerebrum, a greatly reduced tritocerebrum (= stomodaeal bridge), and cheliceral ganglia. The events in the development of the various systems in general closely parallel those described for many other species of spiders, but differ in some important respects from those described for another species of Latrodectus, namely Latrodectus hasselti Thorell.
利岡静一，安仁屋賢一，浦崎長枝. 1957. 沖繩八重山に於ける Latrodectus hasseltii Thorell, 1870 と, その咬螫症の一例に就いて (第9回大会講演要旨). 衞生動物 8(2): 88 [Latrodectus hasseltii collected from Yaeyama Islands, with a clinical case record of this species] ==> PDF|
|1955||Keegan HL. 1955. Spiders of genus Latrodectus. American Midland Naturalist 54(1): 142-152. ==> PDF （分類記載，無料メンバー登録必要）|
Keegan HL. 1952. Geographic Distribution of Latrodectus Hasseltii. The American Journal of Tropical Medicine and Hygiene, November 1952 1:1043-1046. ==> 本文は有料|
Keegan HL, Blauw AS, Anderson RI. 1950. Latrodectus geométricas Koch on Luzon. American Journal of Tropical Medicine 30(6): 901-907. ==> Abstract (本文は有料)|
The following is taken from the authors' summary. Latrodectus geométricas Koch is recorded for the first time from the Philippine Islands, where it was found in three localities on Luzon. It is a common house-infesting species at one air force base., with habits similar to those of L. mactans (F.) in the United States. Observations on length of life, habits and egg-sac production are made on the basis of the study of a colony maintained in the laboratory. Effects of the venom on mice, guineapigs and cats were similar to those reported by other workers using venoms of L. mactans and L. hasseltii Thorell, but indicate a lower degree of toxicity for these animals. There are no records of L. geometricus biting man on Luzon, but the demonstrated toxicity of its venom combined with its close resemblance to L. mactans and L. hasseltii suggests that some of the bites attributed to those species may have been caused by L. geometricus, which occurs in the ranges of both. DDT in spray, aerosol and powder form has been found effective in destroying both adult and immature spiders. Natural enemies on Luzon include unidentified predacious wasps and the egg-sac parasite, Eurytoma arachnovora Hesse, which has not previously been reported from the Philippines.
|1949||Deevey GB. 1949. The developmental history of Latrodectus hasselti (Araneae: Theridiidae). Australian Journal of Ecology 10: 261-264.|
Sivickis PB, Filoteo RS. 1928. Observations on Development of the Spider, Latrodectus hasseltii Thorell. Transactions of the American Microscopical Society 47(1): 11-27. ==> TopPage preview|
... Latrodectus hasseltii is a spider widely distributed throughout the Philippine Islands. On account of its striking red and black color it is considered by the natives as a very dangerous animal. Unsubstantiated stories are circulated that this spider by its poisonous bite can kill ...
|不詳||Breen RG. 年号不詳. Widow Spiders An overview of the Genus Latrodectus. ==> webpage only|