Steatoda Grossa Research Articles

The effect of ingested copper on the structural and cytotoxic properties of Steatoda grossa (Theridiidae) spider silk

Spiders, assigned to macroconcentrators of heavy metals, are particularly threatened by the toxic effects of these chemicals. Until now, it has not been specified to what extent metals alter the processes proceeding in silk glands and if such changes could consequently influence the chemical and structural properties of the spun web threads. In the present study selected biological properties of Steatoda grossa (Theridiidae) silk yarn after nutritional exposure to copper at sublethal doses (0.234 mM CuSO4) were assessed. It was determined both changes in ultrastructure of ampullate glands and hunting web’s architecture as well the cytotoxic effect in model cells (fibroblasts: line ATCC® CCL–1 NCTC clone 929), that were in contact with the analyzed biomaterial. The exposure of spiders to copper caused the occurrence of apoptotic cells in the ampullate glands as well as a significant reduction in the diameter of single fibers in double and multiple connection complexes as compared with control. At both 24 and 72 h of incubation, intensification of apoptotic and necrotic processes was observed in the fibroblast cultures that were remaining in indirect contact with the webs produced by copper–contaminated individuals. In the case of fibroblasts in direct contact with silk from the copper group, a clear cytotoxic effect resulting in an increased frequency of necrosis was observed after 72 h of incubation. The results indicated that copper may change the biological properties of spider silk and compromise its biomaterial properties.

How cadmium and copper change the sensitivity of the hemocytes of Steatoda grossa spider on immunostimulation: qualitative and quantitative analysis

The purpose of this study was to evaluate the sensitivity of hemocytes of adult Steatoda grossa females to cadmium and copper administered orally for 4 weeks or 12 months, and to check the metabolic condition of these cells after immunostimulation with phorbol 12-myristate 13-acetate (PMA). The viability of hemocytes (flow cytometry and luminescence techniques), their ultrastructure (transmission electron microscopy), and the antioxidant activity of hemolymph (superoxide dismutase, catalase, total antioxidant capacity; TAC) were analyzed. The results showed that, compared to copper, cadmium caused severe necrotic changes in hemocytes and impaired oxygen burst reactions and antioxidant responses, regardless of the exposure time. Copper induced degenerative changes only during short-term exposure, but its long-term intoxication did not impair the metabolic processes of hemocytes. Administration of PMA to spiders that were chronically exposed to either of the metals caused an increase in TAC levels in the hemolymph. Although the concentration of ATP in hemocytes was reduced relative to the control, the ADP/ATP ratio did not change, precluding a strong depletion of cellular energy resources. The metabolic condition of hemocytes stabilized with prolonged metal exposure, indicating the activation of defense mechanisms under operating stressors.

Sibling cannibalism in the false widow spider is dependent on spiderling density and the reliable availability of fresh prey

AbstractAdult female spiders lay batches of eggs in silken egg sacs, and after hatching, the spiderlings live for transient periods in their mother's web before dispersing. Sibling cannibalism is frequently observed among spiderlings of many species under conditions of food deprivation. Here, we conducted assays in small Petri dishes with different densities of newly hatched (second instar) spiderlings of the false widow spider, Steatoda grossa, using a split‐clutch design. Prey (freshly killed fruit flies) availability was manipulated both numerically and temporally. Offspring from 10 different females were separated as siblings into densities of two, four, or eight spiderlings per Petri dish and these were provided with either 0 flies (starvation control), two flies, four flies, or eight flies that were replenished weekly or every 3 weeks. A further control was conducted with solitary spiderlings in Petri dishes deprived of flies. The number of surviving spiderlings per Petri dish was counted every 3 days until only one remained (or until death of the solitary spiderling). Our results show that the rate of cannibalism was lower with increasing spiderling density and when fresh flies were replenished more frequently, whereas the number of flies that were provided did not affect cannibalism. In S. grossa, juvenile cannibalism occurs primarily under conditions of extreme food limitation, although in synanthropic habitats where the spider is abundant, it may be an adaptive strategy owing to the potential scarcity of prey. Under certain conditions, cannibalism in spiderlings is adaptive by eliminating competitors and providing nutrient‐rich food.

Spider bite envenomation on Reunion Island

AbstractSpiders are the most abundant group of predators within the Earths ecosystems. On Reunion Island, there are up to 200 known species of spiders. However, the description of the envenomation by the bites of some local spiders have never performed. The objective of this study was to describe the representation of the health risks associated to the six spider species present on the island. The following species were described within the local arachnofauna: Latrodectus geometricus C. L. Koch, 1841 (Theridiidae), Steatoda grossa (C. L. Koch, 1838) (Theridiidae), Loxosceles rufescens (Dufour, 1820) (Sicariidae), Cheiracanthium insulare (Vinson, 1863) (Cheiracanthiidae), Cheiracanthium africanum Lessert, 1921 (Cheiracanthiidae) and Heteropoda venatoria (Linnaeus, 1767) (Sparasidae). This study constituted a first approach to the pathologies encountered by local venomous spider bites. To date, no recorded cases of envenomation linked to these species have been made so far. Some of the species or close species were documented in international literature as responsible for envenomation cases, however, future research should be taken in order to better inform and prepare healthcare professionals within the Reunion Island hospital services to deal with patients with spider bite cases.

Organic salt composition of pressure sensitive adhesives produced by spiders

Natural glues offer great potential as bio-inspired solutions to problems associated with the performance of synthetic adhesives. Spider viscous glues are elastic pressure sensitive adhesives (PSAs) that physically adhere to surfaces on contact across a range of environmental conditions. Extracting useful components from these secretions remains a challenge that can be met by the comparative analyses of functional analogues. Here we used 1H NMR spectroscopy and mass spectrometry to ascertain the organic salt compositions of the PSAs of four different species of Australian spiders belonging to two lineages that independently acquired aqueous gluey secretions: the St Andrew’s cross (Argiope keyserlingi), the redback (Latrodectus hasselti), the false widow (Steatoda grossa), and the daddy long-legs spider (Pholcus phalangiodes). The PSAs from each of these spiders contained similar organic salts, albeit in variable concentrations. The adhesives of the false widow and daddy long-legs spider had mixtures of only a few components, of which betaine predominated, while the PSAs of the other spiders predominantly contained small organic acids such as GABA/GABA-amide, isethionate, and choline salts. Our results suggest that the PSA composition of spiders is likely to be influenced more by environmental factors than evolutionary history and are guided by common principles. Our findings could be valuable for facilitating the design of more sustainable synthetic glues.

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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).

Effects of chronic exposure to cadmium and copper on the proteome profile of hemolymph in false widow spider Steatoda grossa (Theridiidae)

The aim of this study was to evaluate the quantitative and qualitative changes in the proteome of the hemolymph of female Steatoda grossa spiders (Theridiidae) that were chronically exposed to cadmium and copper in food and were additionally immunostimulated (phorbol 12–myristate 13–acetate (PMA); bacterial suspensions: Staphylococcus aureus (G+), Pseudomonas fluorescens (G–). It was found that the expression of nearly 90 proteins was altered in cadmium–intoxicated spiders and more than 60 in copper–exposed individuals. Regardless of the type of metal used, these proteins were mainly overexpressed in the hemolymph of the exposed spiders. On the other hand, immunostimulation did not significantly change the number of proteins with altered expression in metal–intoxicated individuals. Hemocyanin (Hc) was found to be the most abundant of the proteins identified with altered expression. In copper–intoxicated spiders, immunostimulation increased the expression of A-, E–, F–, and G–chain–containing proteins, while in the case of cadmium–intoxicates spiders, it decreased the expression of E– and A–chain–containing Hc and increased the expression of G–chain–containing Hc. Regardless of the type of metal and immunostimulant used, there was an increase in the expression of actin. In addition, cadmium increased the expression of cullin, vimentin, and ceruloplasmin. The changes observed in the expression of hemolymph proteins indicate their protective function in S. grossa (Theridiidae) spiders under conditions of metal exposure.

Origin, structure and functional transition of sex pheromone components in a false widow spider

Female web-building spiders disseminate pheromone from their webs that attracts mate-seeking males and deposit contact pheromone on their webs that induces courtship by males upon arrival. The source of contact and mate attractant pheromone components, and the potential ability of females to adjust their web’s attractiveness, have remained elusive. Here, we report three new contact pheromone components produced by female false black widow spiders, Steatoda grossa: N-4-methylvaleroyl-O-butyroyl-L-serine, N-4-methylvaleroyl-O-isobutyroyl-L-serine and N-4-methylvaleroyl-O-hexanoyl-L-serine. The compounds originate from the posterior aggregate silk gland, induce courtship by males, and web pH-dependently hydrolyse at the carboxylic-ester bond, giving rise to three corresponding carboxylic acids that attract males. A carboxyl ester hydrolase (CEH) is present on webs and likely mediates the functional transition of contact sex pheromone components to the carboxylic acid mate attractant pheromone components. As CEH activity is pH-dependent, and female spiders can manipulate their silk’s pH, they might also actively adjust their webs’ attractiveness.

The effect of selected immunostimulants on hemocytes of the false black widow Steatoda grossa (Theridiidae) spiders under chronic exposition to cadmium

The aim of this study was to analyze whether, and to what extent, long–term exposure to cadmium, administered in sublethal concentrations by the oral route, caused changes in the immune potential of hemocytes in adult female Steatoda grossa spiders. We used artificial and natural immunostimulants, namely phorbol 12–myristate 13–acetate (PMA) and bacterial cell suspension based on Gram–positive (G+, Staphylococcus aureus) and Gram–negative (G−, Pseudomonas fluorescens) bacteria, to compare the status of hemocytes in nonstimulated individuals and those subjected to immunostimulation. After cadmium exposure, the percentage of small nongranular hemocytes in response to G+ cell suspension and PMA mitogen was decreased. Furthermore, in the cadmium–intoxicated spiders the percentage of plasmatocytes after immunostimulation remained lower compared to the complementary control group. Exposure to cadmium also induced several degenerative changes, including typical apoptotic and necrotic changes, in the analyzed types of cells. Immunostimulation by PMA mitogen and G+ bacterial suspension resulted in an increase in the number of cisterns in the rough endoplasmic reticulum of granulocytes, in both the control group and cadmium–treated individuals. These changes were accompanied with a low level of metallothioneins in hemolymph. Chronic cadmium exposure may significantly weaken the immune defense system of spiders during infections.

Identification and quantification of fatty acids in hunting web of adult Steatoda grossa (Theridiidae) female spiders

Abstract This is the first study on composition of fatty acids in hunting web of Steatoda grossa (Theridiidae) spiders and one of only four similar studies ever made. Its main contribution is a discovery that fatty acids not only cover an outside of the web fibers, but they are even more abundantly represented in the fibers’ inner structure. Although little attention has been so far attributed to the contents of fatty acids in spider silks, one has to remember that their biocompatibility combined with an extraordinary tensile strength make them a worth investigating template for material bioengineering studies.

Prey availability affects developmental trade-offs and sexual-size dimorphism in the false widow spider, Steatoda grossa

In many spiders, females are significantly larger than males. Several theories have been postulated to explain sexual size dimorphism (SSD), including differential predation risks experienced by each sex early in life (including female cannibalism of males), male-male competition, and the more costly production of eggs than sperm. However, there is considerable intraspecific variation in the relative size of males and females that is reflected in trade-offs on traits such as growth rate and body size. When SSD favors female size, the body mass ratios between the smallest and largest males is expected to be much greater than in females. Here, growth trajectories and body masses of the false widow spider, Steatoda grossa, were compared in male and female spiders fed continually or intermittently. Males provided with unlimited prey (fruit flies and house crickets) took about 15 weeks to attain full size and sexual maturity and grew to a mean of 25 mg. By contrast, males fed only once every three weeks took approximately 6 weeks longer to reach maturity but were only about half as large (mean 13 mg) as males fed constantly. Females fed intermittently took almost twice as long (45 weeks versus 24 weeks) as constantly-fed females to reach maturity, but were almost 90% as large when fully grown. These results reveal that, although both sexes trade-off development time and body size to achieve the optimal phenotype, rapid development is more important than larger body size in males whereas the opposite is true in females. This finding supports life-history theory underpinning sexual-size dimorphism in some spider lineages.

Know your foe: synanthropic spiders are deterred by semiochemicals of European fire ants.

Many ants prey on spiders, suggesting that web-building spiders may avoid micro-locations near ant colonies or frequented by foraging ants. Here we tested the hypothesis that ant-derived semiochemicals deter synanthropic spiders. To generate stimuli, we exposed filter paper for 12 h to workers of European fire ants, Myrmica rubra, black garden ants, Lasius niger, or western carpenter ants, Camponotus modoc, and then offered select urban spiders in three-chamber olfactometer bioassays a choice between ant-exposed filter paper and unexposed control filter paper. Semiochemical deposits of M. rubra, but not of L. niger or C. modoc, had a significant deterrent effect on subadults of the false black widow, Steatoda grossa, the black widow, Latrodectus hesperus, and the hobo spider, Eratigena agrestis, as well as a moderate (but statistically not significant) deterrent effect on the cross spider, Araneus diadematus. The deterrent effect caused by semiochemical deposits of M. rubra may be attributable to the aggressive nature and efficient foraging of M. rubra in its invaded North American range, exerting selection pressure on community members to recognize M. rubra semiochemicals and to avoid micro-locations occupied by M. rubra.

Herbivore-induced plant volatiles do not affect settling decisions by synanthropic spiders

An underlying assumption of optimal foraging models is that animals are behaviorally, morphologically, and physiologically adapted to maximize their net energy intake. Here we explored whether this concept applies to web-building spiders in a multi-trophic context. If a spider were to build her web next to herbivore-fed-on plants that signal the herbivores’ enemies for help by emitting herbivore-induced plant volatiles (HIPVs), that spider may maximize web captures in the short term. However, she would also risk predation by generalist predators that “listen” to signaling plants to find both herbivore and spider prey, likely resulting in lower overall reproductive fitness for the spider. We tested the hypothesis that HIPVs trigger avoidance responses by web-building spiders. We selected seven common HIPVs and one HIPV elicitor, and in two-choice olfactometer bioassays tested their effect on four synanthropic spider species (false black widow, Steatoda grossa; common cellar spider, Pholcus phalangioides; hobo spider, Eratigena agrestis; western black widow, Latrodectus hesperus). The 8-component HIPV/HIPV elicitor blend had a weak deterrent effect on S. grossa, but the effect did not extend to P. phalangioides, E. agrestis, and L. hesperus. Our findings imply that there was insufficient selection pressure for these spiders to recognize HIPVs in a multi-trophic context, where spiders themselves could become prey if generalist predators or spider-hunting parasitoid wasps were to respond to signaling plants.

Multimodal and multifunctional signaling? - Web reduction courtship behavior in a North American population of the false black widow spider.

Males of widow spiders courting on the web of females engage in web-reduction behavior which entails excising a section of the web, bundling it up, and wrapping it with their silk. Males of the false black widow spider, Steatoda grossa, in European populations also produce stridulatory courtship sound which has not yet been studied in their invaded North American range. Working with a North American population of S. grossa, we tested the hypotheses that (1) web reduction by males renders webs less attractive to rival males; (2) deposition of silk by courting males has an inter-sexual (male-female) signal function that enhances their likelihood of copulation; and (3) stridulatory sound is a courtship signal of males. Testing anemotactic attraction of males in Y-tube olfactometer experiments revealed that reduced webs (indicative of a mated female) and intact webs (indicative of a virgin female) were equally attractive to males. Recording courtship behavior of males with either functional (silk-releasing) spinnerets or spinnerets experimentally occluded on the web of virgin females showed that males with functional spinnerets were more likely to copulate with the female they courted. Although males possess the stridulatory apparatus to produce courtship sound, they did not stridulate when courting or copulating on the web of females. Our data support the conclusion that web-reduction behavior of S. grossa males in their invaded North American range has no long-range effect on mate seeking males. Instead, web-reduction behavior has an inter-sexual signaling function that seems to be linked to functional spinnerets of the courting male. The signal produced by a male likely entails a volatile silk-borne pheromone, but may also embody a gauge of his endurance (the amount of time he engages in web reduction causing web vibrations).

‘Mine or thine’: indiscriminate responses to own and conspecific webs and egg sacs by the false black widow spider, Steatoda grossa (Araneae: Theridiidae)

Female false black widows, Steatoda grossa (Araneae: Theridiidae), build energy-costly webs. We tested the hypotheses (H1, H2) that females prefer their own webs and the chemical extract of their own webs to those of conspecifics, and (H3) that mated females discern between their own egg sacs and those of conspecifics. In choice bioassays, females indiscriminately accepted both their own webs and egg sacs and those of conspecific females, although they chose extracts of webs based on their chemical cues. The females’ indiscriminate responses to webs or egg sacs are likely due to a lack of selection pressure to reject webs or egg sacs of conspecific females.

Karyotype features based on diploid number and sex chromosome system of Steatoda grossa (Araneae: Theridiidae) from Turkey

In this study, karyotypic investigation of Steatoda grossa belonging to the family, Theridiidae was carried out to contribute cytogenetic relationships of the family. A standard air-drying method was used to obtain chromosome slides including three main steps as hypotonisation, fixation and staining. As a result, the diploid number and sex chromosome system was determined as 2n♂=22 (X1X2). All chromosomes were telocentric and gradually decreased in size. Sex chromosomes were positively heteropycnotic in the stages of meiosis I, and isopycnotic in meiosis II. The results showed the similarity with the previous investigations obtained from different populations.

Evaluation of selected biological properties of the hunting web spider (Steatoda grossa, Theridiidae) in the aspect of short- and long-term exposure to cadmium

The study aimed at comparing the effects of short- and long-term exposure of Steatoda grossa female spiders to cadmium on the web's architecture, its energy content, and ultrastructure of ampullate glands. Simple food chain model (medium with 0.25 mM CdCl2 → Drosophila hydei flies → spider (for 4 weeks or 12 months) was used for the exposure. Analysis of Cd content provided evidence that silk fibers of the web are well protected against its incorporation irrespectively of the exposure period. Long-term exposure to cadmium resulted in the occurrence of numerous autophagosomes with degenerated organelles as well as apoptotic and necrotic cells in the ampullate glands. Concurrently, the individual silk fibers building double and multiple combination complexes were significantly thinner than in the control threads. Moreover, exposed spiders spun net with smaller mean calorific value than did the control individuals. Hence, evaluation of both the diameter of silk fibers and calorific value of the web can serve as biomarkers of the effects caused by exposure of these predators to cadmium.

Dodging sexual conflict?—Sub‐adult females of a web‐building spider stay cryptic to mate‐seeking adult males

AbstractAdult males of web‐building spiders often cohabit the webs of sessile sub‐adult (i.e. penultimate instar) females and mate with them as they moult to adults. Often, males accrue benefits from this cohabitation (kleptoparasitism, avoidance of cannibalism, potential polygamy), whereas sub‐adult females may either accrue benefits or incur costs such as curtailed opportunity for mate choice or mate cannibalism. Working with the false black widow spider, Steatoda grossa, we tested the hypothesis that webs of sub‐adult females, unlike those of virgin adult females, lack sex attractant pheromone that mate‐seeking males could detect and exploit for mate location. We tested our hypothesis in laboratory experiments by presenting adult males with binary choices between different types of webs (e.g., webs of adult virgin females, sub‐adult females or sub‐adult males), and methanol extracts of these webs. Males spent more time on webs, or web extracts, of adult virgin females than on webs or web extracts of any other type. Most males (95%) also displayed courtship only on webs, or web extracts, of adult virgin females. Our data demonstrate apparent semiochemical crypsis of sub‐adult females or their webs to mate‐seeking adult males that seem to find sub‐adult females by chance encounter. This crypsis is likely adaptive to sub‐adult females that are in sexual conflict with adult males cohabiting their webs.

Application of thin-layer chromatography to ecotoxicological study with the Steatoda grossa spider web

In the search for biocompatible and biodegradable natural products, much attention of biomedical engineering experts is attracted by spider web (also known as spider silk). Apart from its biocompatibility and biodegradability, the key feature of spider silk is its extraordinary tensile strength, in many cases surpassing that of steel or Kevlar. Although spider silk (unlike that produced by the silk worms) cannot be produced on a mass scale, it can serve as a structural template to be imitated by the organic chemists. The main building blocks of the spider silk proteins, spidroins, are the non-polar and hydrophobic α-amino acids, and the most abundant among them are l-glycine and l-alanine. In this study, we investigated an impact of cadmium chloride (CdCl2) as a toxic anthropogenic environmental pollutant on quantitative levels of glycine, alanine, histidine, and phenylalanine in spider silk produced by the female Steatoda grossa spider kept for the periods of 4 weeks and 12 months, respectively, on cadmi...

Natural Compounds as Spider Repellents: Fact or Myth?

Although some spiders are globally invasive, found at high densities, and may be considered pests (particularly those that are toxic to humans), there are few pest management methods based on experimental data. 'Common wisdom' and advertisements on internet websites assert that a number of natural substances repel spiders. We tested whether the three substances cited most frequently (lemon oil, peppermint oil, and chestnut-fruits) effectively repelled female spiders or whether these were myths. We presented each of the putative repellents versus a control in a two-choice assay and tested responses of females of three invasive spider species in two different families: theridiids, Latrodectus geometricus C. L. Koch (Araneae: Theridiidae) and Steatoda grossa C. L. Koch (Araneae: Theridiidae) and the araneid, Araneus diadematus Clerck . Chestnuts (Araneae: Araneidae) and mint oil strongly repelled L. geometricus and A. diadematus. S. grossa was less sensitive to these chemicals but had a slight tendency to avoid chestnuts. However, lemon oil, the substance most likely to be cited as a repellent (over 1,000,000 hits on Google), had no effect on any of these spiders. We conclude that volatiles released by mint oil and chestnuts may be effective in deterring spider settlement in two different families of spiders, but lemon oil as a repellent is a myth.