Steatoda Triangulosa Research Articles

Non-targeted metabolomics aids in sex pheromone identification: a proof-of-concept study with the triangulate cobweb spider, Steatoda triangulosa

Targeted metabolomics has been widely used in pheromone research but may miss pheromone components in study organisms that produce pheromones in trace amount and/or lack bio-detectors (e.g., antennae) to readily locate them in complex samples. Here, we used non-targeted metabolomics—together with high-performance liquid chromatography–mass spectrometry (HPLC–MS), gas chromatography-MS, and behavioral bioassays—to unravel the sex pheromone of the triangulate cobweb spider, Steatoda triangulosa. A ternary blend of three contact pheromone components [N-4-methylvaleroyl-O-isobutyroyl-l-serine (5), N-3-methylbutyryl-O-isobutyroyl-l-serine (11), and N-3-methylbutyryl-O-butyroyl-l-serine (12)] elicited courtship by S. triangulosa males as effectively as female web extract. Hydrolysis of 5, 11 and 12 at the ester bond gave rise to two mate-attractant pheromone components [butyric acid (7) and isobutyric acid (8)] which attracted S. triangulosa males as effectively as female webs. Pheromone components 11 and 12 are reported in spiders for the first time, and were discovered only through the use of non-targeted metabolomics and GC–MS. All compounds resemble pheromone components previously identified in widow spiders. Our study provides impetus to apply non-targeted metabolomics for pheromone research in a wide range of animal taxa.

On a bite case of Steatoda triangulosa (Walckenaer) (Arachnida: heridiidae) on a human being

The second case of a bite by the “triangulate false widow” Steatoda triangulosa is reported on a human being. The case occurred in San Vicente, Buenos Aires, Argentina on a female 31 years old victim, who woke up felling a nuisance and spotting the spider on her arm. The spider inflicted two bites causing typical steatodism symptoms including local and radiating pain and malaise which lasted for about a day. In addition, the appearance of an erythema on each bite side that lasted about 10 days plus a haematoma in the first bite site which lasted for 3 days. The implications of the case in the context of current research in steatodism is discussed.

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New data on jumping spiders (Salticidae) and tangle-web spiders (Theridiidae) of Armenia are provided on the basis of recently collected specimens in various regions of Armenia. One species, Ballus rufipes (Simon, 1868) is recorded as new to the Caucasus Region, in addition to the following species: Neon reticulatus (Blackwall, 1853), Pellenes brevis (Simon, 1868), Salticus scenicus (Clerck, 1757) and Synageles dalmaticus (Keyserling, 1863) that belong to a family Salticidae, are recorded in Armenia for the first time. A further 7 species of Theridiidae are recorded in Armenia for the first time Kochiura aulica (C. L. Koch, 1838), Steatoda albomaculata (De Geer, 1778), Steatoda bipunctata (Linnaeus, 1758), Steatoda castanea Clerk, 1757, Steatoda grossa (C. L. Koch, 1838), Steatoda paykulliana Walckenaer, 1806 and Steatoda triangulosa (Walckenaer, 1802).

Vertebrate prey capture by Latrodectus mactans (Walckenaer, 1805) and Steatoda triangulosa (Walckenaer, 1802) (Araneae, Theridiidae) provide further insights into the immobilization and hoisting mechanisms of large prey

Spider species across 27 families have been recorded naturally preying upon vertebrates. Intricate three-dimensional webs, predation strategies, and potent neurotoxic venom allow Latrodectus and Steatoda spiders to subdue vertebrate prey that are many times larger and heavier than themselves. Yet, little is known about the behaviour associated with capturing comparatively large vertebrate prey, or how common these predatory events are. We report on two new cases of vertebrate predation by Latrodectinae spiders: a Latrodectus mactans (Walckenaer, 1805) preying on a common house mouse Mus musculus (Linnaeus, 1758) in the USA and a Steatoda triangulosa (Walckenaer, 1802) preying on a Kotschy's gecko Mediodactylus kotschyi (Steindachner, 1870) in Greece. Although predation events on vertebrates by Latrodectus species have been documented in the literature, such events have been sparsely reported for the genus Steatoda. We provide the first record of S. triangulosa preying on M. kotschyi. Such predation events shed light on the multifunctional physiology of the venom and behavioural ecology of these spiders.

Predatory Spiders Associated with the Two Spotted Spider Mite Tetranychus urticae on Two Field Crops in Qalubyia Governorate, Egypt

Five hundred and fifty eight spiders belonging to 11 families of order Araneae were associated with T. urticae and collected on clover and cotton crops at Qaha research station in Qalubyia governorate, Egypt during two successive years, 2013 and 2014. During the period of study, Salticidae was the most abundant of the collected spider followed by Theridiidae, Thomisidae, Philodromidae, Dictynidae, Eutichuridae (Miturgidae), Araneidae, Linyphiidae, Lycosidae, Agelenidae, and Gnaphosidae. The number of the collected spiders, families and percent occurrence of each family varied on the studied crops in different seasons. On clover, the collected families did not include Gnaphosidae in both years of study in addition to Araneidae in 2013 and Lycosidae, Philodromidae and Agelenidae in 2014. On cotton, Lycosidae and Agelenidae were not collected in both years in addition to Gnaphosidae in 2014. Changes of population densities of the monthly collected spiders and their prey, T. urticae, ran nearly in parallel during the whole seasons of cotton with peak in September and up till the prey peak on clover in March. Although the population of T. urticae decreased in the next months following the peak on clover, the spiders continued increasing to reach their peak in May 2013 and 2014. The total number of collected spider’s movable stages was higher in 2013 than 2014 on each crop and on cotton than clover in each year of study. On the other hand, the total number of T. urticae collected was higher in 2014 than 2013 on each crop and on clover than cotton in each year of study. Laboratory studies on life stage duration, food consumption and predation rate of early immatures and adult female of Thanatus albini, Steatoda triangulosa and Thomisus spinifer (family Philodromidae, Theridiidae, Thomisidae, respectively), showed the efficacy of the three selected spider species as predators on adult Tetranychus urticae. Immatures and adult females of the studied spiders consumed more and lived longer when fed on females than males of T. urticae. In immature spiders, the number of consumed prey/spider, the daily predation rate and mostly the stage duration (except S. triangulosa) gradually increased by increasing age from the first to third spiderling. In female adult spiders, the 3 parameters, except predation rates of Thomisus spinifer, were the highest in female T. albini, followed by T. spinifer then S. triangulosa. The significance of the obtained result was discussed.

An Introductory Study of House Spiders (Araneae) in Belgium

More than 800 spiders were collected in 43 houses heated in winter, distributed mainly in the northern part of Belgium. Information required for the collections to be eligible for the project was: address, construction year, type of house, and surroundings. The spiders were qualified as ‘house spiders’ or ‘garden spiders’. Of the 93 species collected, 19 could be defined as house spiders. Pholcus phalangioides was the most common, followed by Eratigena atrica and Steatoda triangulosa. Garden spiders enter the house much more often in houses in a rural environment than in those situated in clusters, and mainly in spring. The spiders are most common in autumn when many of them are breeding. The common house spiders colonize houses shortly after their construction.

Mechanical testing of spider silk at cryogenic temperatures

A method and results for mechanical testing of spider silk in extreme environments is presented. In particular, silk from the spider Steatoda triangulosa is harvested, and samples are subjected to cryogenic temperatures by means of liquid nitrogen submersion. Samples are destructively tested while immersed in liquid nitrogen, and the stress–strain characteristics are compared to those of silk at room temperature. The strength, elasticity, and toughness of the cryogenically submersed silk are determined. It is found that on average, silk is 64% stronger while immersed in liquid nitrogen (i.e., at −196 °C). The testing method could also be used for testing of silk in chemically hostile environments.

Impact of beta radiation on the strength of Steatoda triangulosa spider silk

Silk from the spider Steatoda triangulosa is harvested, and samples are subjected to various doses of beta radiation using a scanning electron microscope (SEM). Irradiated and unirradiated samples are destructively tested to determine the stress–strain characteristics. From these data, the strength of the irradiated silk is determined as a function of dose.

Introduced Spiders (Arachnida: Araneae) In An Artificial Ecosystem In Eastern Canada

Four spider species were found in the artificial tropical ecosystem of the Biodome de Montreal (Quebec, Canada): Steatoda triangulosa (Theridiidae), previously reported from Quebec and Ontario, Coleosoma floridanum (Theridiidae), Theridion melanostictum (Theridiidae), and Scytodes fusca (Scytodidae), which have never been recorded in Quebec. These species were likely to have been imported from Florida along with plants used in the reconstruction of this tropical ecosystem. The occurrences of these species demonstrate an inefficiency in quarantine procedures. Each species is diagnosed and illustrated in order to facilitate their monitoring and possible invasion of natural habitats from this source of introduction.

Un cas de stéatodisme observé en Languedoc après morsure d’araignée du genre Steatoda

Cobweb spiders (genus Steatoda) are small species closely related to black widow spiders and their bites can induce envenomation known as steatodism. A 46-year-old man in the Gard district in southern France was sleeping in his bed when a spider (identification Steatoda triangulosa) bit him. Clinical manifestations included local signs together with systemic neurological symptoms resembling low-grade latrodectism (black widow envenomation). This first-recorded case of steatodism in southern France differs in several ways from the classic pattern of latrodectism in Europe: the bite occurred in home during winter and mild symptoms resolved quickly without hospital care. In endemic areas (in France the Mediterranean climate zone: Provence, Languedoc and Corsica), steatodism should be considered when low-grade latrodectism is observed.

Homologs of Drosophila Appendage Genes in the Patterning of Arthropod Limbs

Studies of the genes involved in patterning the appendages of Drosophila melanogaster have revealed a system of signaling and transcriptional regulation that is responsible for specifying the proximo-distal limb axis. Here we report the expression patterns of presumptive homologs of the Drosophila genes extradenticle, dachshund, nubbin, ventral veins lacking (a.k.a. Cf1-a), and Dll in the limbs of the woodlouse Porcellio scaber and the spider Steatoda triangulosa. Although the expression domains of the appendage genes roughly correspond to those of Drosophila, their relative positions and segmental affiliation are distinct. In addition, the expression patterns of the appendage genes allows a resolution of the segmental composition of different appendages within crustacean and spider embryos. We conclude that certain limb types, e.g., mouthparts, appear to be derived from a leg-like ground-plan via the elimination/fusion of the intermediate and distal podomeres. Moreover, we observe just such a modification during the transformation of the anterior legs into mouthparts in P. scaber. Although our data do not unequivocally resolve the question of homology of the arthropod leg segments, they do provide evidence for a single conserved proximo-distal patterning system in the development of noninsect arthropod limbs.

Chelicerate Hox genes and the homology of arthropod segments.

Genes of the homeotic complex (HOM-C) in insects and vertebrates are required for the specification of segments along the antero-posterior axis. Multiple paralogues of the Hox genes in the horseshoe crab Limulus poliphemus have been used as evidence for HOM-C duplications in the Chelicerata. We addressed this possibility through a limited PCR survey to sample the homeoboxes of two spider species, Steatoda triangulosa and Achaearanea tepidariorum. The survey did not provide evidence for multiple Hox clusters although we have found apparent duplicate copies of proboscipedia (pb) and Deformed (Dfd). In addition, we have cloned larger cDNA fragments of pb, zerknullt (zen/Hox3) and Dfd. These fragments allowed the determination of mRNA distribution by in situ hybridization. Our results are similar to the previously published expression patterns of Hox genes from another spider and an oribatid mite. Previous studies compared spider/mite Hox gene expression patterns with those of insects and argued for a pattern of segmental homology based on the assumption that the co-linear anterior boundaries of the Hox domains can be used as markers. To test this assumption we performed a comparative analysis of the expression patterns for UBX/ABD-A in chelicerates, myriapods, crustaceans, and insects. We conclude that the anterior boundary can be and is changed considerably during arthropod evolution and, therefore, Hox expression patterns should not be used as the sole criterion for identifying homology in different classes of arthropods.