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In this study, spider fauna of Çeşme, Karaburun and Urla districts in the İzmir Peninsula were investigated. Examined specimens were collected from various localities in the region between December 2016 and April 2018. As a result of the study, 497 adult spider specimens (299 ♀♀, 198 ♂♂) were collected; 88 genera and 109 species belonging to 33 families were identified. Of these species, since five individuals belonging to different families are juvenile, their identification is left at the genus level. All species are new records for İzmir Peninsula except: Argyrodes argyrodes (Walckenaer, 1841), Dipoena galilaea Levy & Amitai, 1981, Dysdera fragaria Deeleman-Reinhold, 1988, Scytodes thoracica (Latreille, 1802), Scytodes velutina Heineken & Lowe, 1832, Tetragnatha nitens (Savigny, 1825) and Thanatus pictus L. Koch, 1881. [ABSTRACT FROM AUTHOR]

The genus Argyrodes Simon, 1864 includes kleptoparasitic spiders. The synanthropic spider Argyrodes miniaceus is specialised in the invasion and exploitation of the webs created by members of family Araneidae. In the present study, Argyrodes miniaceus (Doleschall, 1857) is reported for the first time from the Western Ghats of India. [ABSTRACT FROM AUTHOR]

Kleptoparasitic spiders live and forage in the webs of other spiders. Using vibratory cues generated by the host spider during prey capture, they leave their resting positions in the upper peripheries of the host web and move towards the centre of the web where they feed along with the host spider or steal small pieces of prey. While the triggers for initiating the foraging raids are known, there is little information about the fine-scale trajectory dynamics in this model system. We mapped the movement of the kleptoparasite Argyrodes elevatus in the web of the host Trichonephila clavipes. We filmed the movement of the kleptoparasite spiders and quantified the trajectory shape, speed, heading directions and path revisitation. Our results show that kleptoparasitic spider movement is spatially structured, with higher levels of speed at the peripheries and slower in the centre of the web. We found a high level of variation in trajectory shapes between individuals. We found that the majority of heading orientations were away from the hub suggesting that detouring or repeated approaches are an essential component of kleptoparasite movement strategies. Our results of the revisitation rate also confirm this pattern, where locations close to the hub were revisited more often than in the periphery. The kleptoparasite–host spider system is a promising model to study fine-scale movement patterns in small bounded spaces. [ABSTRACT FROM AUTHOR]

Abstract: Expansion of oil palm agriculture is currently one of the main drivers of habitat modification in Southeast Asia. Habitat modification can have significant effects on biodiversity, ecosystem function, and interactions between species by altering species abundances or the available resources in an ecosystem. Increasing complexity within modified habitats has the potential to maintain biodiversity and preserve species interactions. We investigated trophic interactions between Argyrodes miniaceus, a cleptoparasitic spider, and its Nephila spp. spider hosts in mature oil palm plantations in Sumatra, Indonesia. A. miniaceus co‐occupy the webs of Nephila spp. females and survive by stealing prey items caught in the web. We examined the effects of experimentally manipulated understory vegetation complexity on the density and abundance of A. miniaceus in Nephila spp. webs. Experimental understory treatments included enhanced complexity, standard complexity, and reduced complexity understory vegetation, which had been established as part of the ongoing Biodiversity and Ecosystem Function in Tropical Agriculture (BEFTA) Project. A. miniaceus density ranged from 14.4 to 31.4 spiders per square meter of web, with significantly lower densities found in reduced vegetation complexity treatments compared with both enhanced and standard treatment plots. A. miniaceus abundance per plot was also significantly lower in reduced complexity than in standard and enhanced complexity plots. Synthesis and applications: Maintenance of understory vegetation complexity contributes to the preservation of spider host–cleptoparasite relationships in oil palm plantations. Understory structural complexity in these simplified agroecosystems therefore helps to support abundant spider populations, a functionally important taxon in agricultural landscapes. In addition, management for more structurally complex agricultural habitats can support more complex trophic interactions in tropical agroecosystems. [ABSTRACT FROM AUTHOR]

We report three interesting species of comb-footed spiders (Aranaea: Theridiidae) belonging to three different genera, namely, Latrodectus, Rhomphaea and Coleosoma, of which Latrodectus erythromelas is a first record to India, while Rhomphaea projiciens and Coleosoma floridanum are a first record to Andhra Pradesh. We provide the detailed description of Latrodectus erythromelas, Rhomphaea projiciens and Coleosoma floridanum. [ABSTRACT FROM AUTHOR]

We examined complex geographical patterns in the morphology of a kleptoparasitic spider, Argyrodes kumadai, across its distributional range in Japan. To disentangle biotic and abiotic factors underlying morphological variation, latitudinal trends were investigated in two traits, body size and relative leg length, across separate transition zones for host use and voltinism. Statistical analyses revealed complex sawtooth clines. Adult body size dramatically changed at the transition zones for host use and voltinism, and exhibited a latitudinal decline following the converse to Bergmann's cline under the same host use and voltinism in both sexes. A similar pattern was observed for relative leg length in females but not in males. A genetic basis for a part of observed differences in morphology was supported by a common-garden experiment. Our data suggest that local adaptation to factors other than season length such as resource availability (here associated with host use) obscures underlying responses to latitude. [ABSTRACT FROM AUTHOR]

We examined how the web structure of host spiders affects the locomotor ability of the kleptoparasitic spider Argyrodes kumadai. We compared two populations of A. kumadai differing with respect to whether the host used was Agelena silvatica (Agelenidae) or Cyrtophora ikomosanensis (Araneidae). The barrier web of Agelena had a higher thread density than that of Cyrtophora, which presumably constrains locomotion of A. kumadai in Agelena webs. A reciprocal transplant experiment into different webs revealed that, in complex webs, the A. kumadai population using Agelena as a host walked faster than the A. kumadai population using Cyrtophora; however, no such difference was found in simple webs. This suggested that A. kumadai using Agelena are better adapted to the webs of their native host with regard to their locomotor ability than are A. kumadai using Cyrtophora. The prey capture success of A. kumadai, as estimated by the foraging response of the host to prey and the walking speed of A. kumadai, revealed that the population of A. kumadai using Agelena captured larger prey much more frequently than the population using Cyrtophora. Thus, the greater locomotor ability of A. kumadai using Agelena appears to be adaptive for enhancing prey acquisition in Agelena webs where prey-stealing opportunities are severely limited. We conclude that both physical web architecture and the foraging behaviour of the host are important selective agents on locomotor ability in Argyrodes. [ABSTRACT FROM AUTHOR]

The article presents a study on the species of the spider Argyrodes Simon 1864 (Araneae: Theridiidae) such as Argyrodes nephilae Taczanowski 1872 in Andhra Pradesh, India. It states that various instruments were used in the study including digital dial calipers, ocular micrometer, and Canon super macro digital camera. It mentions that the collected specimens of spiders were preserved in 70% alcohol and stored in the Natural History Museum of Osmania University, Hyderabad.

This study describes a case of interspecific aggregation involving a spider's web and its effect on web architecture of another species of spider. On two transects of 100 m each, one with Nephila clavipes (Linnaeus 1767) webs and one without, we noted the spiders associated, or not, with N. clavipes webs, and compared the web architecture of the most commonly associated species, Leucauge venusta (Walckenaer 1842). The transect with N. clavipes contained more spiders in general than that without N. clavipes, most of which were L. venusta for both transects. The height above ground of L. venusta webs associated with N. clavipes presented a larger range of distribution, which closely mimicked that of N. clavipes webs except when the N. clavipes web was at ground level. Leucauge venusta webs were more inclined when in association with N. clavipes (49.4 ± 3.3° vs 20.4 ± 2.0°). We concluded that L. venusta clearly prefers to be associated with N. clavipes, and we discuss the possible advantages of this association. [ABSTRACT FROM AUTHOR]

This study examined the endemic species of kleptoparasitic spiders in the genus Argyrodes from the Hawaiian Islands, a lineage previously known in the archipelago from only a single described species, Argyrodes hawaiiensis Simon. Here, two additional endemic species are described, A. ilipoepoe Rivera and Gillespie, n. sp., and A. laha Rivera and Gillespie, n. sp., with their biogeographical patterns, and the allotype female and paratypes of A. hawaiiensis are designated. As with A. hawaiiensis, both new species are commonly found as kleptoparasites on the sheet webs of large nocturnal spiders in the genus Orsonwelles (Linyphiidae). Hawaiian Argyrodes are characterized by small and rounded abdomens, unpronounced clypeal projections, and variably long fangs. Argyrodes hawaiiensis; A. ilipoepoe, n. sp.; and A. laha, n. sp., include all the known endemic representatives of the group in the Hawaiian Islands, which mostly occur in wet and mesic forests. [ABSTRACT FROM AUTHOR]

The presentation of nutritional resources as nuptial gifts before or during the mating process is well known among insects, but has only rarely been documented in spiders. Here, we report on observations and a series of photographs made during field studies in Fortin de las Flores, Veracruz, Mexico, which, although a single anecdotal report, represent a potentially significant finding. A male of the kleptoparasitic spider Argyrodes elevatus Taczanowski 1873 (Araneae, Theridiidae) was observed stealing a prey item from within a communal web of its host, the colonial orb-weaver Metepeira incrassata F.O. Pickard-Cambridge 1903 (Araneae, Araneidae). The male A. elevatus then carried and presented the prey item to a female, waited nearby until she began feeding, and copulated with her as she fed upon it. As far as is known, this is the first report of kleptoparasitic Argyrodes apparently utilizing a prey item stolen from a host spider as a nuptial gift. [ABSTRACT FROM AUTHOR]

Although well studied, the role of spider webs in attracting prey and the role of web ornaments remain open questions. We carried out a field study to determine whether webs of Nephila clavipes (Linnaeus 1767) attract insects. Nephila builds large orb-webs with debris-decoration that host kleptobiotic Argyrodes spiders. We studied the potential prey of Nephila with sticky traps placed in two similar linear plots. One plot contained 20 Nephila webs, and the other was cleared of Nephila webs. We measured the number and size of the insects caught in the traps. We compared the size of the trapped insects with prey caught by Nephila and gleaned by Argyrodes. In the plot with Nephila webs we collected 314 individuals versus 105 individuals in the plot without Nephila. Species of Diptera and Coleoptera were captured most frequently. Four saprophagous families, Phoridae and Sciaridae (both Diptera), Staphylinidac and Elateridae (both Coleoptera), were more abundant in the plot with Nephila webs. We show for the first time under natural conditions that prey attraction is most efficient for saprophagous insects, suggesting that the debris-decoration in Nephila webs attracts this guild. We also found that the size of some insects captured does not correspond to the range of prey consumed by Nephila, but to that of kleptobiotic Argyrodes spiders. We hypothesize that the debris-decoration may be used by Nephila as a strategy to limit food competition with Argyrodes. [ABSTRACT FROM AUTHOR]

Several species of kleptoparasitic and araneophagic spiders (Araneae: Family Theridiidae, Subfamily Argyrodinae) are found in colonial webs of the orb-weaving spider Metepeira incrassata (Araneae, Araneidae) from Mexico, where they steal food and/or prey upon their spider hosts. Census data from natural M. incrassata colonies reveal that the incidence of these species increases with colony size. This pattern may reflect the presence of several other orb-weaving spiders, each with their own kleptoparasitic species, invading larger M. incrassata colonies. As the number of these associated spiders increases, so does the density and number of Argyrodinae species in M. incrassata colonies, suggesting that associated spiders might reduce their own kleptoparasite load by building their webs within M. incrassata colonies. This represents a twofold cost to M. incrassata, as a field enclosure experiment revealed that a primarily kleptoparasitic species ( Argyrodes elevatus) may reduce prey available to their hosts, but a kleptoparasitic/araneophagic species ( Neospintharus concisus) inflicts high mortality upon M. incrassata. However, the cost of kleptoparasitism and predation by these species may be offset in part for M. incrassata individuals in large colonies by certain defensive mechanisms inherent in groups, i.e., “attack-abatement” and “selfish herd” effects. We conclude that increased occurrence of kleptoparasitic and/or predatory Argyrodinae spiders is a consequence of colonial web building and is an important potential cost of group living for colonial web-building spiders. [ABSTRACT FROM AUTHOR]

1. A kleptoparasitic spider, Argyrodes kumadai, is known to use phylogenetically unrelated host species in different regions – Cyrtophora moluccensis (Araneidae) in south-west Japan and Agelena silvatica (Agelenidae) in north-east Japan. The work reported here examined whether differences in host characters affect prey acquisition of A. kumadai. 2. Field surveys showed that prey-biomass capture rate of Argyrodes was significantly higher in populations parasitising Cyrtophora than in populations parasitising Agelena. Although Argyrodes appeared to catch fewer prey within Cyrtophora webs, they were able to feed upon substantially larger prey. 3. Differences in prey-biomass capture rate were found to reflect differences in host traits rather than regional differences in potential prey availability. Individuals in populations parasitising Cyrtophora were observed to acquire prey via a number of foraging tactics that included stealing wrapped food bundles, feeding upon prey remains and, in the case of large prey items, feeding together with the host. In contrast, individuals in populations parasitising Agelena were only ever observed to feed upon small prey items ignored by its host. 4. This variability in prey acquisition between kleptoparasite populations reflected different opportunities for feeding within their respective host webs – opportunities that were primarily determined by the foraging behaviour of the host. One key trait associated with host foraging behaviour was host-web structure, namely the presence/absence of a retreat. [ABSTRACT FROM AUTHOR]

This paper offers the first cladistic analysis of a wide selection of theridiid genera based on morphological data. The analysis treats 53 theridiid taxa representing 32 genera ( Achaearanea, Anelosimus, Ameridion, Argyrodes, Ariamnes, Carniella, Cerocida, Chrysso, Coleosoma, Dipoena, Emertonella, Enoplognatha, Episinus, Euryopis, Faiditus, Kochiura, Latrodectus, Neospintharus, Nesticodes, Pholcomma, Phoroncidia, Rhomphaea, Robertus, Selkirkiella, Spintharus, Steatoda, Stemmops, Theridion, Theridula, Thymoites, Thwaitesia, Tidarren) and eight outgroup taxa representing the families Nesticidae ( Eidmanella and Nesticus), Synotaxidae ( Synotaxus, two species), Pimoidae ( Pimoa), Linyphiidae ( Linyphia), Tetragnathidae ( Tetragnatha) and Araneidae ( Argiope). The parsimony analysis of 242 morphological and behavioural characters found a single, most parsimonious tree. The monophyly of theridiids and their sister relationship with nesticids is strongly supported. The recent resurrection of Ariamnes and Rhomphaea from Argyrodes made the latter paraphyletic. However, Ariamnes and Rhomphaea are characterized by an array of characters, and Argyrodes still contains dramatically distinct clades for which names are available: Faiditus (removed from synonymy − RS) and Neospintharus (RS). These revalidations provide a classification with greater information content and utility. These three genera, along with Ariamnes, Rhomphaea and Spheropistha, comprise the subfamily Argyrodinae. The monophyly and composition of the subfamilies Hadrotarsinae, Spintharinae, Pholcommatinae, Latrodectinae and Theridiinae are discussed. Theridion is paraphyletic and in need of revision. Anelosimus as currently circumscribed is paraphyletic, a problem resolved by revalidating Selkirkiella (RS) and Kochiura (RS). Numerous new combinations are established. The results suggest the monophyletic origin of both kleptoparasitism and araneophagy in the lineage leading to Argyrodinae, negating hypotheses that either arose from the other. Sociality evolved multiple times within the family, accounting for as much as one fourth of the origins of social behaviour among all spiders. No losses of sociality are implied. The hypothesis of maternal care as the pathway to sociality receives support. Evolution of theridiid webs is complex, with multiple modifications and loss of the basic theridiid cobweb. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 141, 447–626. [ABSTRACT FROM AUTHOR]

Most Argyrodes spiders live in the webs of other spiders as kleptoparasites, stealing food from the host and scavenging small prey from the web. We observed three species of Argyrodes from the Micronesian island of Guam to learn (1) if Argyrodes species differ in their use of host-species webs, (2) whether some Argyrodes species occur more often in certain habitats, (3) whether population size of Argyrodes is a function of web size, and (4) how the presence of congeners affects population size on a web. Argyrodes lived most often in the large, long-lasting orb webs of Argiope appensa and Cyrtophora mollucensis , and, rarely, in the smaller, less durable orb webs of Neoscona spp. and Leucauge spp. Argyrodes argentatus and Argyrodes sp. A frequently co-occurred in Argiope webs, but A. argentatus was more common in beach strand and open disturbed habitats, while Argyrodes sp. A was more common in shaded native forest. The abundances of A. argentatus and Argyrodes sp. A in Argiope webs and the abundance of Argyrodes sp. B in Cyrtophora webs were positively correlated with the areas of the webs' prey-catching surfaces. The abundance of A. argentatus was inversely proportional to that of Argyrodes sp. A on Argiope webs and to that of Argyrodes sp. B on Cyrtophora webs, suggesting interspecific avoidance. [ABSTRACT FROM AUTHOR]

Spiders of the genus Argyrodes are kleptoparasites that steal prey from other web spiders. Recent studies have shown that in addition to stealing prey, they occasionally eat the silk of the host spider webs. How Argyrodes alters the two foraging tactics in the field is still unknown. The foraging behaviour of Argyrodes flavescens was observed in the south-western part of Japan where prey availability changes greatly with season. Silk-eating behaviour was commonly observed when insect prey availability on host webs was low, but when prey was abundant, only prey-stealing behaviour was observed. Spiders spent more time feeding on silk than on prey when prey was scarce. Moreover, in the season when most individuals fed on silk, only a small portion of individuals consumed prey. These results suggest that silk eating is an important alternative foraging tactic under seasonally changing environments. [ABSTRACT FROM AUTHOR]

Spiders from the theridiid genus Argyrodes exhibit considerable variation in foraging tactics. However, little is known about the conditions under which Argyrodes spiders switch foraging tactics. Argyrodes flavescens (Pickard-Cambridge) is commonly found in the webs of another spider Nephila pilipes (Fabricius) in Singapore. In this study, a series of prey-choice tests were conducted for A. flavescens, both in the presence and absence of N. pilipes, to investigate the state-dependent prey type preference of A. flavescens. It was found that, in the absence of N. pilipes, well-fed A. flavescens took houseflies more than fruit flies, but starved A. flavescens took more fruit flies than houseflies. Whether N. pilipes spiders were present or absent, both well-fed and starved A. flavescens preferred living prey and rarely took wrapped prey of any kind. When well fed, A. flavescens rarely took mealworms. However, when starved, A. flavescens tended to take freshly captured prey, and also tended to feed together with N. pilipes on a housefly or mealworm captured by N. pilipes. Whether A. flavescens were absent or present, both well-fed and starved N. pilipes took mealworm larvae more often than they took houseflies, and they never attacked fruit flies. This is the first study to show that Argyrodes spiders alter their foraging tactics depending on hunger level, prey type, or the presence of the host. In doing so, Argyrodes spiders may maximize their energy gain and minimize predation risk in different circumstances. [ABSTRACT FROM AUTHOR]

Most kleptoparasitic Argyrodes spiders rely exclusively on host spider webs for obtaining their food. Because their densities occasionally reach high levels within a restricted area, competitive interactions may be important for determining the density of these unique spiders. Here I used two Argyrodes species commonly found on webs of the large orb-web spider Nephila clavata to clarify whether inter- and intraspecific competition influences abundance and within-web distribution by using observational data and field experiment. Removing Argyrodes flavescens from the host webs induced a remarkably high immigration of that species while density on control webs remained almost at the same level, which is evidence for strong intraspecific competition. Larger individuals of A. flavescens were located more frequently at the capture area of the host webs where it is easy to access prey ignored by the host spider, and spiders immigrating into webs from which that species had been removed were smaller in body size, suggesting interference competition for space among conspecific kleptoparasites. Argyrodes bonadea increased in number on webs from which A. flavescens had been removed, and the increase was correlated with the number of A. flavescens removed. This finding is evidence for interspecific competition that is rarely reported in spiders. A multiple regression model including numbers of a conspecific parasite as well as web and body sizes of the host spider could not detect competitive interactions between species, suggesting the importance of experimental approaches. [ABSTRACT FROM AUTHOR]

Argyrodes globosus (Keyserling, 1884) is a small kleptoparasite spider that steals prey from the web of web-building spiders. In coffee plantations in the south of Mexico it was observed to parasitize five species: Gasteracantha cancriformis (Linnaeus, 1785) and Verrucosa arenata (Walckenaer, 1841) (Araneidae), Leucauge mariana (Keyserling, 1881) and Leucauge venusta (Walckenaer, 1841) (morphologically indistinguishable species) and Leucauge argyra (White, 1841) (Tetragnathidae). G. cancriformis was more frequently parasitized than the other hosts. An analysis of web diameter for each host species indicated that for L. mariana/venusta, L. argyra and V. arenata the kleptoparasite was associated with webs of a certain size range (23-33cm diameter) although a far larger range of web sizes was available (17-50cm diameter). The average size of the web of G. cancriformis (~23cm) appeared to be close to the preferred size for the kleptoparasite and this, together with an apparent absence of host aggression, may explain the prevalence of A. globosus with this host. For the parasite, web size choice may involve a tradeoff among diverse factors including prey capture rate, ease of access to the web and aggressive behaviour by the host. [ABSTRACT FROM AUTHOR]

In this study, we documented that the kleptoparasitic spiders Argyroes elvatus consume and assimilate web material from the host spider Nephila clavipes. We also demonstrated quantitatively that the amount of web material consumed by the kleptopa asite is equivalent to the amount of insect material comsumed when host vigilance is low, as expected when foraging conditions are very good. Argyrodes vary in their impact on their hosts, as they may steal large prey, small prey, or silk. This host-kiepto parasite interaction is therefore an ideal system for experimentally cramming a variable producer-consumer interaction. We compare our experimental results to published experiments showing that the impact of Arg on a Nephila host can be deleterious when foraging conditions are poor. [ABSTRACT FROM AUTHOR]

Nuptial gifts in spiders are poorly documented. We report on an observation and on photographs of a colonial web in San Vicente de Chucurl, Santander, Colombia, which suggest a likely case of nuptial gift behavior in a male of the kleptoparasitic spider Argyrodes elevatus Taczanowski 1873 (Araneae: Theridiidae). Pictures of a male A. elevatus holding a dead Cyclosa huila Levi I999 (Araneae: Araneidae) wrapped in silk, in close proximity to a female A. elevatus facing him, document the couple at various moments at dusk and early the following morning. While no copulation is seen. these pictures suggest an attempt by the male to deliver a nuptial gift. Our observations support a recent report of apparent nuptial gift behavior in A. elevatus and raise questions on the foraging behavior of kleptoparasitic spiders in communal webs. [ABSTRACT FROM AUTHOR]

In the trade-off between food and safety, the role of aggressive intraspecific interactions has not been extensively examined. Here I present information on this system using a kleptoparasitic spider, Argyrodts antipodiana, and its host spider and potential predator, Eriophora pustulosa. A. antipodiana can feed either at a potentially dangerous site (the hub of its host's web with the host), or at a relatively safe site (on food bundles around the edge of the host's web). I found that A. antipodiana can gain food very quickly when feeding with the host, apparently by exploiting the host's ability to digest the prey. Thus A. antipodiana follows predictions based on foraging models in that it accepts a higher predation risk at the hub because of the higher food payoff. A. antipodiana also aggressively competes for access to more food. However, aggressive competition increases the predation risk from the host, especially at tile hub where the host is very close. Consequently, A. antipodiana modifies its level of intraspecific aggressiveness in accordance with its position on the web: at the hub, where the cost of aggression is high (due to predation risk), A. antipodiana reduces its aggressiveness, but it is aggressive away from the hub when competing for food bundles. The ability of A. antipodiana to change interaction intensity as a function of its position on the web enables it to exploit a rich, but risky, food source and provides a new angle for examining food and safety trade offs in light of intraspecific competition for food [ABSTRACT FROM AUTHOR]