Journal of Arachnology最新文献

{"title":"Mating and cannibalism dynamics of the fishing spider Dolomedes scriptus Hentz, 1845 (Araneae: Pisauridae)","authors":"Daniel Schoenberg, E. Hebets, L. Sullivan‐Beckers","doi":"10.1636/JoA-S-20-024","DOIUrl":"https://doi.org/10.1636/JoA-S-20-024","url":null,"abstract":"Abstract. Sexual cannibalism is common in many species of arachnids. Studies investigating Dolomedes tenebrosus Hentz, 1844, have even discovered the occurrence of obligatory male self-sacrifice during copulation. In this system, females subsequently cannibalize males, and this cannibalism leads to higher fitness for both partners. Unfortunately, our understanding of the evolution of such an extreme mating system is challenged by the absence of information for close relatives. To that end, this study explores the courtship behavior, mating system and cannibalism dynamics of the spider Dolomedes scriptus Hentz, 1845. To determine whether female and male D. scriptus mate multiply, we recorded interactions of repeatedly exposed focal females and focal males to new mating partners for three days. We also quantified attacks and cannibalism events that occurred both before and after every copulation. We found male D. scriptus court females by waving their forelegs during their approach and tapping the females prior to mounting. In our remating trials, none of the female D. scriptus accepted additional males after their first mating over the three-day period. In contrast, male D. scriptus were polygynous, often mating with multiple females. Across the trials, sexual size dimorphism was a predictor of whether mating occurred, with similarly sized pairs being more likely to mate. Additionally, previously mated females were less likely to cannibalize males—an unusual pattern for spiders. Like other species of Dolomedes Latreille, 1804, our results suggest a strong role of female aggression in D. scriptus mating system dynamics.","PeriodicalId":51076,"journal":{"name":"Journal of Arachnology","volume":"50 1","pages":"56 - 66"},"PeriodicalIF":1.0,"publicationDate":"2022-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45566817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sinarachna nigricornis and genus-specific host utilization of Araneus spiders by the genus Sinarachna (Hymenoptera: Ichneumonidae)","authors":"S. Korenko, L. Cernecká, Martina Dorková, J. Sýkora, P. Gajdoš","doi":"10.1636/JoA-S-21-012","DOIUrl":"https://doi.org/10.1636/JoA-S-21-012","url":null,"abstract":"Abstract. The ichneumonid parasitoid Sinarachna nigricornis (Holmgren, 1860) was associated only with Araneus sturmi (Hahn, 1831) in the studied locality. The normal capturing orb web of A. sturmi was always vertical and had a median of 18 radii and 9 spirals in laboratory conditions. When spiders did not build capture webs, they built resting and molting webs which consisted of a few threads between the ends of the provided tree twigs. There were no significant differences in the number of radials and spirals between unparasitized spiders and spiders parasitized by early instar parasitoid larvae. Araneus sturmi under manipulation by S. nigricornis built a modified cocoon web, serving parasitoid larva pupation. S. nigricornis exhibited high plasticity in the architecture of the cocoon web induced by its penultimate instar larva. The most common cocoon web was of 3D architecture with a small central silk platform, from which the wasp cocoon was suspended by its apical end (72% of webs). In 22% of cases, the cocoon web consisted only of a few threads, presumably resembling a molting web. In one case, the manipulated spider built a 3D tangle, though radials and the central hub (typical for the normal capturing web) were also present. The genus specificity of the cocoon web architecture described here, in which the typical cocoon web exhibits a sparse but strong 3D architecture and in which the wasp cocoon is suspended by its apical end at the center, is expected for the genus Sinarachna.","PeriodicalId":51076,"journal":{"name":"Journal of Arachnology","volume":"50 1","pages":"51 - 55"},"PeriodicalIF":1.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45420861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observations of dispersal in the brown recluse spider, Loxosceles reclusa (Araneae: Sicariidae)","authors":"K. L. Cramer, D. Evers","doi":"10.1636/JoA-S-21-003","DOIUrl":"https://doi.org/10.1636/JoA-S-21-003","url":null,"abstract":"Abstract. We studied dispersal of brown recluse spiders, Loxosceles reclusa (Gertsch & Mulaik, 1940), around an infested urban garage using pitfall traps. Over a four-month period, 23 were captured from a source population that averaged 100 individuals observed in nocturnal censuses. Loxosceles reclusa were captured in far lower proportions compared to their potential source population size than were other spiders such as theridiids and agelenids that also resided in the garage, albeit in far lower numbers. Dispersal was weakly positively correlated with the source population size. We compare our findings to anecdotal reports from prior studies and the general consensus that brown recluse spiders are poor dispersers to argue for more detailed examination of the movement and specific habitat requirements of this medically important spider. Habitat specificity and high mortality during dispersal may help explain the highly clustered spatial distribution of brown recluse spiders, not only a lack of attempted emigration.","PeriodicalId":51076,"journal":{"name":"Journal of Arachnology","volume":"50 1","pages":"23 - 26"},"PeriodicalIF":1.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48438100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Niche partitioning and intraspecific shared webs in two species of Modisimus Simon, 1893 (Pholcidae: Araneae)","authors":"Jorge D. Carballo-Morales, Camila Delgado-Montes, Leydi V. Auccacusi-Choque, Miriam Reyes-Ortiz, A. Aisenberg","doi":"10.1636/JoA-S-21-020","DOIUrl":"https://doi.org/10.1636/JoA-S-21-020","url":null,"abstract":"Abstract. The pholcid spiders Modisimus bribri Huber, 1998 and M. guatuso Huber, 1998 construct three-dimensional webs, including sheet dome and irregular shapes, occasionally shared by males and females. We studied species spatial disaggregation and confirmed web-sharing and prey capture dominance in shared webs. We observed 22 M. bribri and 25 M. guatuso webs and recorded their height above the ground, dome dimensions, and web-sharing. In shared webs, we recorded which individual captured prey. Modisimus bribri builds webs at greater heights (∼6.5 times), with larger dimensions (∼2 times) than M. guatuso. In both species, neither the occupant sex nor the number of individuals on the web had a significant effect on web dimensions. We confirmed differential web location between species and did not find evidence of chivalrous dominance in prey-capture in shared webs. This study contributes to the general knowledge of three-dimensional web-building spiders, posing new questions for future research.","PeriodicalId":51076,"journal":{"name":"Journal of Arachnology","volume":"50 1","pages":"43 - 46"},"PeriodicalIF":1.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46072657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diet study of geckos reveals the first records of pseudoscorpions on Desertas Islands (Cabo Verde)","authors":"Bárbara Santos, C. Pinho, František Št’áhlavský, Vanessa A. Mata, R. Lopes, R. Vasconcelos","doi":"10.1636/JoA-S-20-085","DOIUrl":"https://doi.org/10.1636/JoA-S-20-085","url":null,"abstract":"Abstract. Pseudoscorpions are known worldwide and yet are poorly studied mainly due to the difficulty of detecting them. Among their predators are ground-dwelling taxa, such as arthropods, amphibians, birds, and reptiles. Only four pseudoscorpion species are known to occur in the Cabo Verde Archipelago, and none in the Desertas Islands, located in the northwest of the country. In this study, we record the first two species for the Desertas Islands. We used molecular and morphological methods to taxonomically identify the specimens retrieved from reptile faecal pellets and pitfall traps. We identified the presence of Garypus cf. saxicola on Raso Islet, Olpium pallipes (Lucas, 1849) on Raso and Santa Luzia Island, and a putative new species of Olpium L. Koch, 1873 on Branco Islet. This study emphasizes how an indirect measure of biodiversity and ecological interactions via potential predators, using non-invasive sampling combined with metabarcoding and morphological studies, can be used to uncover unknown biodiversity, particularly of cryptic groups from highly inaccessible locations. Likewise, this study highlights the lack of 16S genetic resources for pseudoscorpions in online reference databases.","PeriodicalId":51076,"journal":{"name":"Journal of Arachnology","volume":"50 1","pages":"39 - 42"},"PeriodicalIF":1.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45373879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oophagy in spiders: consumption of invertebrate and vertebrate eggs","authors":"M. Nyffeler, J. Gibbons","doi":"10.1636/JoA-S-21-016","DOIUrl":"https://doi.org/10.1636/JoA-S-21-016","url":null,"abstract":"Abstract. In this paper, we present an update on our knowledge on egg predation (oophagy) by spiders. Based on a survey of 233 reports, ghost spiders (Anyphaenidae), lynx spiders (Oxyopidae), jumping spiders (Salticidae), and yellow sac spiders (Cheiracanthiidae) were the most prominent groups of spiders engaged in oophagy. Around 75% of the reports referred to the consumption of lepidopteran and spider eggs worldwide. Another 10% referred to the consumption of eggs/embryos of anurans – especially predation upon embryos of glass frogs (Centrolenidae) by spiders from the families Anyphaenidae and Trechaleidae in the Neotropics. The remaining 17% included rare instances of feeding on eggs of coleopterans, dermapterans, dipterans, heteropterans, homopterans, hymenopterans, acarids, neuropterans, opilionids, and squamates. Our study demonstrates that oophagy in spiders is much more widespread than previously thought, both geographically and taxonomically. The finding that spiders feed on eggs/embryos from so many different invertebrate and vertebrate taxa is novel.","PeriodicalId":51076,"journal":{"name":"Journal of Arachnology","volume":"50 1","pages":"33 - 38"},"PeriodicalIF":1.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45581646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New records of the not-so-rare males of the parthenogenetic scorpion Tityus stigmurus (Thorell, 1876) (Scorpiones: Buthidae)","authors":"Stênio Ítalo Araújo Foerster, W. Dionisio-da-Silva, Adriana B. dos Santos, Cleide Maria Ribeiro de Albuquerque, André Felipe de Araújo Lira","doi":"10.1636/JoA-S-21-009","DOIUrl":"https://doi.org/10.1636/JoA-S-21-009","url":null,"abstract":"Abstract. Parthenogenesis and sex-ratio bias may lead to erroneous assumptions concerning the natural history of some arachnids. To help address this issue, this study provides new data on the sex ratio and geographic distribution of sexual populations of the scorpion Tityus stigmurus (Thorell, 1876). Ultraviolet light lanterns were used to detect specimens during nocturnal searches performed in both urban and non-urban environments scattered thorough northeastern Brazil. Males of T. stigmurus were reported for 10 new localities, and although we did not find males in urban environments, non-urban populations presented near symmetrical sex ratios. Such results suggest that reproductive strategies in this species may be modulated by environmental conditions. Also, the general tendency of less biased sex ratios in non-urban environments reported here is in accordance with previous studies that indicated the occurrence of geographical parthenogenesis in this species. Thereby, we propose that sexual populations of T. stigmurus are less rare than previously reported.","PeriodicalId":51076,"journal":{"name":"Journal of Arachnology","volume":"50 1","pages":"27 - 29"},"PeriodicalIF":1.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41682070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Home on the range: a pilot study on solifuge (Solifugae: Eremobatidae) site fidelity at Rocky Mountain Arsenal National Wildlife Refuge","authors":"R. R. Jones, Diana L. Batista-Perales, Erika L. Garcia","doi":"10.1636/JoA-S-20-094","DOIUrl":"https://doi.org/10.1636/JoA-S-20-094","url":null,"abstract":"Abstract. Many animals, including many arachnids, return to an established “home” after an active period. Although desert-adapted solifuges shelter from the sun in retreats, it is unknown if these solifuges “home” to and re-use the same retreats over multiple consecutive periods. We sought to investigate whether individual solifuges exhibit site fidelity (philopatry) and could be found repeatedly within the same small geographic area using a simple mark-and-recapture study design. Over the course of the seven-day study period, nine of 46 solifuges were recaptured once, and two were recaptured a second time, with an average of 4.17 m between encounters. This rate of recapture is suggestive that solifuges remain in or return to the same geographic area over some period of time – a prerequisite for homing behavior. Further investigation is warranted to establish if solifuges are repeatedly using the same retreats, and if so, how they are navigating during homing.","PeriodicalId":51076,"journal":{"name":"Journal of Arachnology","volume":"50 1","pages":"47 - 50"},"PeriodicalIF":1.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48161532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ctenus igatu sp. nov. (Araneae: Ctenidae): a new subterranean spider from Brazil with an analysis of troglomorphic traits","authors":"Igor Cizauskas, Daniele Polotow, J. Gallão, M. E. Bichuette, A. Brescovit","doi":"10.1636/JoA-S-20-068","DOIUrl":"https://doi.org/10.1636/JoA-S-20-068","url":null,"abstract":"Abstract. In this work we describe Ctenus igatu sp. nov., the first ctenid spider from South America with conspicuous troglomorphic traits, including elongated appendages, reduction of eyes, and body depigmentation. The new species is only known to occur in a unique sandstone cave from the state of Bahia, north-eastern Brazil. The morphology of the genitalia suggests that Ctenus igatu sp. nov. is closely related to Ctenus fasciatus Mello-Leitão, 1943, a facultative subterranean species from caves in the state of São Paulo, south-eastern Brazil. In addition, we compared morphological traits possibly related to the isolation in subterranean habitats, such as ratios between carapace length vs. leg IV length and eye diameters vs. carapace length, of 19 species of Ctenus (17 epigean species, C. fasciatus and the new troglobitic species described herein). Our analysis showed that both C. fasciatus as C. igatu sp. nov. have morphological troglomorphisms, with C. igatu sp. nov. showing marked specializations to subterranean life.","PeriodicalId":51076,"journal":{"name":"Journal of Arachnology","volume":"50 1","pages":"1 - 12"},"PeriodicalIF":1.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41689287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiled chromosomal diversity in the Araneidae (Araneomorphae): the highest diploid number among entelegynes and the first record of the X1X2X3X4 Sex Chromosome System in the family","authors":"Lucas Henrique Bonfim Souza, Caroline Correia Costa, B. C. Silva, Debora Duarte Dutra, Arthur dos Santos Montanholi, Beatriz Oliveira, S. Roghanian, Larissa Candido Lemos, Henrique Ranieri Covali Pontes, Aline Agatha de Pádua, Rebeca Rocha Sobrinho dos Santos Dias, A. Brescovit, D. Araujo","doi":"10.1636/JoA-S-20-071","DOIUrl":"https://doi.org/10.1636/JoA-S-20-071","url":null,"abstract":"Abstract. The Araneidae is among the most speciose spider families, but there are few karyotype studies (1.9%) and some species-rich clades are without any chromosomal study. Understanding the evolution of chromosome number and Sex Chromosome Systems is made more difficult by many uncertain evolutionary relationships within the family. In this work, the chromosomal analysis of eight araneid species (Acacesia benigna Glueck, 1994, Actinosoma pentacanthum (Walckenaer, 1841), Alpaida bicornuta (Taczanowski, 1878), Dubiepeira Levi, 1991 sp., Gasteracantha cancriformis (Linnaeus, 1758), Parawixia bistriata (Rengger, 1836), Verrucosa meridionalis (Keyserling, 1892) and Verrucosa scapofracta Lise, Kesster & Silva, 2015), contribute to discussions of some evolutionary scenarios of chromosome evolution. The gonads were submitted to colchicine treatment, hypotonization, slide preparation, and Giemsa staining. The species analyzed showed 2n♂ = 24 (11II + X1X2), except Dubiepeira sp. with 2n♂ = 41 (19II + X1X2X3), and both Verrucosa species, which presented 2n♂ = 47 (22II + X1X2X3) in V. meridionalis and 2n♂ = 50 (23II + X1X2X3X4) in V. scapofracta. The species analyzed possess all chromosomes with acro/telocentric chromosomal morphology. The 2n♂ = 24, X1X2 found in most species studied here is the most frequent karyotype in the Araneidae. This study presents the first chromosomal data for the diverse clade “Micrathenines”, the highest diploid number among entelegynes (2n♂ = 50), and the first record of an X1X2X3X4 in the Araneidae. The chromosome data suggest a series of fission events in the origin of Verrucosa karyotypes, and a close relationship between Dubiepeira sp. and Araneus ventricosus (L. Koch, 1878). Moreover, Alpaida bicornuta can be cytotaxonomically distinguished of other Alpaida species karyotyped up to now.","PeriodicalId":51076,"journal":{"name":"Journal of Arachnology","volume":"50 1","pages":"13 - 22"},"PeriodicalIF":1.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49491989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}