Journal articles on the topic 'Orb web spiders'
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1
Zhang, Shichang, Teck Hui Koh, Wee Khee Seah, Yee Hing Lai, Mark A. Elgar, and Daiqin Li. "A novel property of spider silk: chemical defence against ants." Proceedings of the Royal Society B: Biological Sciences 279, no. 1734 (November 23, 2011): 1824–30. http://dx.doi.org/10.1098/rspb.2011.2193.
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Spider webs are made of silk, the properties of which ensure remarkable efficiency at capturing prey. However, remaining on, or near, the web exposes the resident spiders to many potential predators, such as ants. Surprisingly, ants are rarely reported foraging on the webs of orb-weaving spiders, despite the formidable capacity of ants to subdue prey and repel enemies, the diversity and abundance of orb-web spiders, and the nutritional value of the web and resident spider. We explain this paradox by reporting a novel property of the silk produced by the orb-web spider Nephila antipodiana (Walckenaer). These spiders deposit on the silk a pyrrolidine alkaloid (2-pyrrolidinone) that provides protection from ant invasion. Furthermore, the ontogenetic change in the production of 2-pyrrolidinone suggests that this compound represents an adaptive response to the threat of natural enemies, rather than a simple by-product of silk synthesis: while 2-pyrrolidinone occurs on the silk threads produced by adult and large juvenile spiders, it is absent on threads produced by small juvenile spiders, whose threads are sufficiently thin to be inaccessible to ants.
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Mulder, Tom, Beth Mortimer, and Fritz Vollrath. "Functional flexibility in a spider's orb web." Journal of Experimental Biology 223, no. 23 (November 12, 2020): jeb234070. http://dx.doi.org/10.1242/jeb.234070.
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ABSTRACTWeb spiders rely on vibrations propagated via their web to identify, locate and capture entangled prey. Here, we experimentally tested the robustness of the orb weaver's predation strategy when webs are severely distorted and silk tensions are drastically altered throughout the web, a common occurrence in the wild. We assessed prey identification efficiency by comparing the spider's initial reaction times towards a fruit fly trapped in the web, we measured location efficiency by comparing times and number of tugging bouts performed, and we determined capture efficiency by comparing capture times. It emerged that spiders are capable of identifying, locating and capturing prey in distorted webs, albeit taking somewhat longer to do so.
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Sensenig, Andrew T., Kimberly A. Lorentz, Sean P. Kelly, and Todd A. Blackledge. "Spider orb webs rely on radial threads to absorb prey kinetic energy." Journal of The Royal Society Interface 9, no. 73 (March 19, 2012): 1880–91. http://dx.doi.org/10.1098/rsif.2011.0851.
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The kinetic energy of flying insect prey is a formidable challenge for orb-weaving spiders. These spiders construct two-dimensional, round webs from a combination of stiff, strong radial silk and highly elastic, glue-coated capture spirals. Orb webs must first stop the flight of insect prey and then retain those insects long enough to be subdued by the spiders. Consequently, spider silks rank among the toughest known biomaterials. The large number of silk threads composing a web suggests that aerodynamic dissipation may also play an important role in stopping prey. Here, we quantify energy dissipation in orb webs spun by diverse species of spiders using data derived from high-speed videos of web deformation under prey impact. By integrating video data with material testing of silks, we compare the relative contributions of radial silk, the capture spiral and aerodynamic dissipation. Radial silk dominated energy absorption in all webs, with the potential to account for approximately 100 per cent of the work of stopping prey in larger webs. The most generous estimates for the roles of capture spirals and aerodynamic dissipation show that they rarely contribute more than 30 per cent and 10 per cent of the total work of stopping prey, respectively, and then only for smaller orb webs. The reliance of spider orb webs upon internal energy absorption by radial threads for prey capture suggests that the material properties of the capture spirals are largely unconstrained by the selective pressures of stopping prey and can instead evolve freely in response to alternative functional constraints such as adhering to prey.
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Mortimer, B. "A Spider’s Vibration Landscape: Adaptations to Promote Vibrational Information Transfer in Orb Webs." Integrative and Comparative Biology 59, no. 6 (May 20, 2019): 1636–45. http://dx.doi.org/10.1093/icb/icz043.
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Abstract Spider orb webs are used not only for catching prey, but also for transmitting vibrational information to the spider. Vibrational information propagates from biological sources, such as potential prey or mates, but also abiotic sources, such as wind. Like other animals, the spider must cope with physical constraints acting on the propagation of vibrational information along surfaces and through materials—including loss of energy, distortion, and filtering. The spider mitigates these physical constraints by making its orb web from up to five different types of silks, closely controlling silk use and properties during web building. In particular, control of web geometry, silk tension, and silk stiffness allows spiders to adjust how vibrations spread throughout the web, as well as their amplitude and speed of propagation, which directly influences energy loss, distortion, and filtering. Turning to how spiders use this information, spiders use lyriform organs distributed across their eight legs as vibration sensors. Spiders can adjust coupling to the silk fibers and use posture to modify vibrational information as it moves from the web to the sensors. Spiders do not sense all vibrations equally—they are least sensitive to low frequencies (<30 Hz) and most sensitive to high frequencies (ca. 1 kHz). This sensitivity pattern cannot be explained purely by the frequency range of biological inputs. The role of physical and evolutionary constraints is discussed to explain spider vibration sensitivity and a role of vibration sensors to detect objects on the web as a form of echolocation is also discussed.
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Fisher, David N., Jonathan N. Pruitt, and Justin Yeager. "Orb-weaving spiders show a correlated syndrome of morphology and web structure in the wild." Biological Journal of the Linnean Society 131, no. 2 (August 28, 2020): 449–63. http://dx.doi.org/10.1093/biolinnean/blaa104.
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Abstract Extended phenotypes are traits that exist outside the physical body of organisms. Despite their role in the lives of the organisms that express them and other organisms influenced by extended phenotypes, the consistency and covariance with morphological and behavioural traits of extended phenotypes has rarely been evaluated. We repeatedly measured an extended phenotype involved in prey acquisition (web structure) of wild orb-weaving spiders (Micrathena vigorsii), which re-build their webs daily. We related web structure to behaviours and spider body length. Web diameter and web density were repeatable among individuals, reaction to a predation threat was very marginally so, and response to a prey stimulus and web evenness were not repeatable. Larger spiders spun wider webs, had webs with increased thread spacing, and the spider possibly tended to react more slowly to a predation threat. When a spider built a relatively larger web it was also a relatively less dense and less even web. The repeatability of web construction and relationship with spider body size we found may be common features of intra-population variation in web structure in spiders. By estimating the consistency and covariances of extended phenotypes we can begin to evaluate what maintains their variation and how they might evolve.
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Zschokke, Samuel, Yann Hénaut, Suresh P. Benjamin, and J. Alvaro García-Ballinas. "Prey-capture strategies in sympatric web-building spiders." Canadian Journal of Zoology 84, no. 7 (July 1, 2006): 964–73. http://dx.doi.org/10.1139/z06-074.
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Arthropods in several orders use traps to capture prey. Such trap-building predators expend most of their foraging energy prior to any prey contact. Nevertheless, relative investments in trap construction and actual prey capture may vary among trap builders, and they are likely to face a trade-off between building very effective but energetically costly traps and building less effective traps requiring faster reaction times when attacking prey. We analysed this trade-off in a field experiment by comparing the prey capture behaviour of four different sympatric web-building spiders (Araneae: Araneidae, Nephilidae, Tetragnathidae, Theridiidae) with the retention times of five different prey types in the webs of these spiders. Retention times differed greatly among webs and among prey types. The vertical orb webs retained prey longer than the horizontal orb web and the sheet web, and active prey escaped more quickly than less active prey. Among spiders with orb webs, the spider with the web that retained prey for the shortest time was the fastest to capture prey, thus confirming the expected trade-off between building long-retaining webs and attacking slowly versus building short-retaining webs and attacking more rapidly. The sheet web, however, neither retained prey for an appreciable period of time nor facilitated rapid prey capture. We suggest that this low capture effectiveness of sheet webs is compensated by their lower maintenance costs.
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Ximenes, Nathalia G., Vinicius De Souza Moraes, Jean C. G. Ortega, and Felipe M. Gawryszewski. "Color lures in orb-weaving spiders: a meta-analysis." Behavioral Ecology 31, no. 2 (January 21, 2020): 568–76. http://dx.doi.org/10.1093/beheco/arz210.
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Abstract Lures are deceptive strategies that exploit sensory biases in prey, usually mimicking a prey’s mate or food item. Several predators exploit plant–pollinator systems, where visual signals are an essential part of interspecific interactions. Many diurnal, and even nocturnal, orb-web spiders present conspicuous body coloration or bright color patches. These bright colors are regarded as color-based lures that exploit biases present in insect visual systems, possibly mimicking flower colors. The prey attraction hypothesis was proposed more than 20 years ago to explain orb-web spider coloration. Although most data gathered so far has corroborated the predictions of the prey attraction hypothesis, there are several studies that refute these predictions. We conducted a multilevel phylogenetic meta-analysis to assess the magnitude of the effect of conspicuous orb-web spider body coloration on prey attraction. We found a positive effect in favor of the prey attraction hypothesis; however, there was substantial heterogeneity between studies. Experimental designs comparing conspicuous spiders to painted spiders or empty webs did not explain between-studies heterogeneity. The lack of theoretical explanation behind the prey attraction hypothesis makes it challenging to address which components influence prey attraction. Future studies could evaluate whether color is part of a multicomponent signal and test alternative hypotheses for the evolution of spider colors, such as predator avoidance and thermoregulation.
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Folt, Brian, and Witold Lapinski. "New observations of frog and lizard predation by wandering and orb-weaver spiders in Costa Rica." Phyllomedusa: Journal of Herpetology 16, no. 2 (December 21, 2017): 269. http://dx.doi.org/10.11606/issn.2316-9079.v16i2p269-277.
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Studies have suggested that predation by spiders may be an important force regulating life history in neotropical frogs and lizards, but detailed descriptions of predator-prey relationships are few. Here we describe novel observations where spiders contributed to the mortality of frogs and lizards in northeastern Costa Rica, and we corrected or clarified three identification errors of spiders from the literature. The most frequently observed predators were wandering spiders (Ctenidae), which seem to be generalist predators on frogs and lizards. An orb-weaver spider (Araneidae) also contributed to frog mortality, likely after the frog became entangled in the spider’s web. More detailed studies are needed to elucidate the role that spider predation contributes to frog and lizard demography in neotropical forests.
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Blackledge, Todd, and John Wenzel. "SILK MEDIATED DEFENSE BY AN ORB WEB SPIDER AGAINST PREDATORY MUD-DAUBER WASPS." Behaviour 138, no. 2 (2001): 155–71. http://dx.doi.org/10.1163/15685390151074357.
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AbstractStabilimenta are zigzag and spiral designs of seemingly conspicuous silk included at the centers of many spider webs. We examined the association of stabilimenta with the ability of spiders to defend themselves against predatory mud-dauber wasps. We found that Argiope trifasciata (Araneae, Araneidae) were significantly more likely to survive attacks by Chalybion caeruleum and Sceliphron caementarium (Hymenoptera, Sphecidae) when spiders included stabilimenta in webs. This association could not be explained by factors such as differences in sizes or conditions of spiders nor locations of webs. We suggest that stabilimenta may function to delay pursuit of spiders as they drop from webs by physically blocking wasps, camouflaging spiders or distracting attacking wasps. Stabilimenta may function in a role very similar to the retreats built by many other genera of spiders and appear to be an adaptation to reduce the predation pressure faced by spiders that have evolved foraging habits at highly exposed diurnal web sites.
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Penney, David, and Vicente M. Ortuño. "Oldest true orb-weaving spider (Araneae: Araneidae)." Biology Letters 2, no. 3 (June 14, 2006): 447–50. http://dx.doi.org/10.1098/rsbl.2006.0506.
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The aerial orb web woven by spiders of the family Araneidae typifies these organisms to laypersons and scientists alike. Here we describe the oldest fossil species of this family, which is preserved in amber from Álava, Spain and represents the first record of Araneidae from the Lower Cretaceous. The fossils provide direct evidence that all three major orb web weaving families: Araneidae, Tetragnathidae and Uloboridae had evolved by this time, confirming the antiquity of the use of this remarkable structure as a prey capture strategy by spiders. Given the complex and stereotyped movements that all orb weavers use to construct their webs, there is little question regarding their common origin, which must have occurred in the Jurassic or earlier. Thus, various forms of this formidable prey capture mechanism were already in place by the time of the explosive Cretaceous co-radiation of angiosperms and their flying insect pollinators. This permitted a similar co-radiation of spider predators with their flying insect prey, presumably without the need for a ‘catch-up lag phase’ for the spiders.
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Knight, D. P., and F. Vollrath. "Spinning an elastic ribbon of spider silk." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 357, no. 1418 (February 28, 2002): 219–27. http://dx.doi.org/10.1098/rstb.2001.1026.
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The Sicarid spider Loxosceles laeta spins broad but very thin ribbons of elastic silk that it uses to form a retreat and to capture prey. A structural investigation into this spider's silk and spinning apparatus shows that these ribbons are spun from a gland homologous to the major ampullate gland of orb web spiders. The Loxosceles gland is constructed from the same basic parts (separate transverse zones in the gland, a duct and spigot) as other spider silk glands but construction details are highly specialized. These differences are thought to relate to different ways of spinning silk in the two groups of spiders. Loxosceles uses conventional die extrusion, feeding a liquid dope (spinning solution) to the slit–like die to form a flat ribbon, while orb web spiders use an extrusion process in which the silk dope is processed in an elongated duct to produce a cylindrical thread. This is achieved by the combination of an initial internal draw down, well inside the duct, and a final draw down, after the silk has left the spigot. The spinning mechanism in Loxosceles may be more ancestral.
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Walter, André, Constanze Westphal, Peter Bliss, and Robin F. A. Moritz. "Drinking behaviour of the orb web spider Argiope bruennichi (Araneae; Araneidae)." Behaviour 148, no. 11-13 (2011): 1295–309. http://dx.doi.org/10.1163/000579511x603292.
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Abstract Water is essential for survival in terrestrial animals. Balancing the water budget can be achieved by avoiding water loss and gaining water. In arthropods drinking as a process of water gain is well investigated in insects. In spiders drinking has only been shown to be present in cursorial spiders but not revealed for web builders. However, some orb web spiders were observed to occasionally ingest water droplets in the web. We here tested whether this reflects drinking. We subjected individual Argiope bruennichi spiders to two different treatments — 'water deprivation' vs. 'water saturation'. We conducted drinking tests by recording the spider's behavioural response to spraying the web with defined amounts of water. After spraying A. bruennichi searched the silk-overstitched web hub for water droplets and ingested them. Individuals that experienced the water deprivation treatment showed significantly more water ingesting behaviours, revealing that this response represents a true drinking mode. All individuals exclusively searched the covered web hubs. We further demonstrated that this structure can retain water for up to 40 min providing an effective substrate for the spiders to drink from. Hence, without the need of leaving the web the silk-covered hubs may help A. bruennichi spiders to balance their water budget.
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Hesselberg, Thomas. "Exploration behaviour and behavioural flexibility in orb-web spiders: A review." Current Zoology 61, no. 2 (April 1, 2015): 313–27. http://dx.doi.org/10.1093/czoolo/61.2.313.
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Abstract Orb-web spiders and their webs constitute an ideal model system in which to study behavioural flexibility and spatial cognition in invertebrates due to the easily quantifiable nature of the orb web. A large number of studies demonstrate how spiders are able to modify the geometry of their webs in response to a range of different conditions including the ability to adapt their webs to spatial constraints. However, the mechanisms behind this impressive web-building flexibility in these cognitively limited animals remain poorly explored. One possible mechanism though may be spatial learning during the spiders’ exploration of their immediate surroundings. This review discusses the importance of exploration behaviour, the reliance on simple behavioural rules, and the use of already laid threads as guidelines for web-building in orb-web spiders. The focus is on the spiders’ ability to detect and adapt their webs to space limitations and other spatial disruptions. I will also review the few published studies on how spatial information is gathered during the exploration phase and discuss the possibility of the use of ‘cognitive map’-like processes in spiders. Finally, the review provides suggestions for designing experimental studies to shed light on whether spiders gather metric information during the site exploration (cognitive map hypothesis) or rely on more simple binary information in combination with previously laid threads to build their webs (stigmergy hypothesis).
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Pasquet, Alain, Camille Toscani, and Mylène Anotaux. "Influence of aging on brain and web characteristics of an orb web spider." Journal of Ethology 36, no. 1 (November 23, 2017): 85–91. http://dx.doi.org/10.1007/s10164-017-0530-z.
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Abstract In animals, it is known that age affects the abilities of the brain. In spiders, we showed that aging affects web characteristics due to behavioral alterations during web building. In this study, we investigated the effects of age on the associations between morphological changes to the spider brain and changes in web characteristics. The orb web spider Zygiella x-notata (Araneae, Araneidae) was used to test these relationships. Experiments were conducted on young (19 ± 2 days after adult molt, N = 13) and old (146 ± 32 days, N = 20) virgin females. The brain volume decreased with age (by 10%). Age also had an impact on the number of anomalies in the capture area generated during web building. The statistical relationships between the volume of the brain and web characteristics showed that there was an effect of age on both. Our results showed that in spiders, aging affects the brain volume and correlates with characteristics (anomalies) of the web. As web building is the result of complex behavioral processes, we suggest that aging affects spider behavior by causing some brain alterations.
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Nakata, Kensuke. "Spatial learning affects thread tension control in orb-web spiders." Biology Letters 9, no. 4 (August 23, 2013): 20130052. http://dx.doi.org/10.1098/rsbl.2013.0052.
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Although it is well known that spatial learning can be important in the biology of predators that actively move around in search for food, comparatively little is known about ways in which spatial learning might function in the strategies of sit-and-wait predators. In this study, Cyclosa octotuberculata , an orb-web spider that uses its legs to contract radial threads of its web to increase thread tension, was trained to capture prey in limited web sectors. After training, spiders that had captured prey in horizontal web sectors applied more tension on radial threads connected to horizontal sectors than spiders that had captured prey in vertical sectors. This result suggests that the effect of experience on C. octotuberculata 's behaviour is not expressed in the way the trained spider responds to prey-derived stimuli and is instead expressed in behaviour by which the spider anticipates the likely direction from which prey will arrive in the future. This illustrates that learning can be important even when the predator remains in one location during foraging bouts.
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Hesselberg, Thomas, Daniel Simonsen, and Carlos Juan. "Do cave orb spiders show unique behavioural adaptations to subterranean life? A review of the evidence." Behaviour 156, no. 10 (2019): 969–96. http://dx.doi.org/10.1163/1568539x-00003564.
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Abstract Interest for subterranean biology has risen sharply in recent years due to the simplicity of the cave environment. However, most studies have focussed on morphology with few studies looking at behaviour. The cave orb spiders show some unique behavioural adaptations compared to other orb spiders, including rudimentary orb webs, off-web foraging and a complex life cycle with a surface phase. Here, we compare these behavioural adaptations in the European Meta menardi and Meta bourneti to similar behaviours in surface-dwelling orb spiders. We find that current data suggest (1) an extreme reduction in the number of frame threads, (2) evidence of capturing non-flying prey, but not necessarily evidence for off-web foraging and (3) dispersal through a surface-dwelling life stage, but with data lacking on the role of ballooning and their return to caves. We conclude that Meta spiders have potential as model organisms for studies on behavioural adaptations and flexibility.
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Coddington, Jonathan A., Ingi Agnarsson, Chris A. Hamilton, and Jason E. Bond. "Spiders did not repeatedly gain, but repeatedly lost, foraging webs." PeerJ 7 (April 4, 2019): e6703. http://dx.doi.org/10.7717/peerj.6703.
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Much genomic-scale, especially transcriptomic, data on spider phylogeny has accumulated in the last few years. These data have recently been used to investigate the diverse architectures and the origin of spider webs, concluding that the ancestral spider spun no foraging web, that spider webs evolvedde novo10–14 times, and that the orb web evolved at least three times. These findings in fact result from a particular phylogenetic character coding strategy, specifically coding theabsenceof webs as logically equivalent, and homologous to, 10 other observable (i.e., not absent) web architectures. “Absence” of webs should be regarded as inapplicable data. To be analyzed properly by character optimization algorithms, it should be coded as “?” because these codes—or their equivalent—are handled differently by such algorithms. Additional problems include critical misspellings of taxon names from one analysis to the next (misspellings cause some optimization algorithms to drop terminals, which affects taxon sampling and results), and mistakes in spider natural history. In sum, the method causes character optimization algorithms to produce counter-intuitive results, and does not distinguish absence from secondary loss. Proper treatment of missing entries and corrected data instead imply that foraging webs are primitive for spiders and that webs have been lost ∼5–7 times, not gained 10–14 times. The orb web, specifically, may be homologous (originated only once) although lost 2–6 times.
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GAN, Wenjin, Fengxiang Liu, Zengtao Zhang, and Daiqin LI. "Predator perception of detritus and eggsac decorations spun by orb-web spiders Cyclosa octotuberculata: Do they function to camouflage the spiders?" Current Zoology 56, no. 3 (June 1, 2010): 379–87. http://dx.doi.org/10.1093/czoolo/56.3.379.
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Abstract Camouflage is one of the most widespread and powerful strategies that animals use to make detection/recognition more difficult. Many orb-web spiders of the genus Cyclosa add prey remains, plant debris, moults, and/or eggsacs to their webs called web decorations. Web decorations resembling spider body colour pattern have been considered to camouflage the spider from predators. While this camouflage is obvious from a human's perspective, it has rarely been investigated from a predator's perspective. In this study, we tested the visibility of web decorations by calculating chromatic and achromatic contrasts of detritus and eggsac decorations built by Cyclosa octotuberculata, against four different backgrounds viewed by both bird (e.g., blue tits) and hymenopteran (e.g. wasps) predators. We showed that both juvenile and adult spiders on webs with detritus or egg-sac decorations were undetectable by both hymenopteran and bird predators over short and long distances. Our results thus suggest that decorating webs with detritus or eggsacs by C. octotuberculata may camouflage the spiders from both hymenopteran and bird predators in their common habitats.
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Soley, Fernando-G. "A possible role of decorations in spiderwebs as protection devices that distract predators." Revista de Biología Tropical 67, no. 2SUPL (May 14, 2019): S164—S173. http://dx.doi.org/10.15517/rbt.v67i2supl.37227.
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Several functions have been proposed for silk decorations (i.e., stabilimenta) in spiderwebs. One hypothesis is that web decorations protect spiders from predators, either by concealing the spiders, physically shielding them, or by deflecting predatory attacks. This study uses data gathered in opportunistic manner when studying the behavior of Stenolemus giraffa, an assassin bug that preys almost exclusively on web-building spiders. Stenolemus giraffa approach orb spiders on foot, and usually capture the spiders at the hub region of the web. When pursuing spiders, S. giraffa routinely tap the web with their antennae, and also tap the spiders prior to attacking them. The observations available from this study suggest that S. giraffa got “distracted” momentarily by the decorations in the webs of Purumitra sp. (Uloboridae) and Argiope katherina (Araneidae). In some instances, the assassin bugs tapped these structures for several seconds or minutes instead of tapping the adjacent spiders. In interactions with A. katherina, S. giraffa was more successful at capturing the spiders when the webs lacked decorations; however, sample sizes are small (this could not be tested for Purumitra sp. because only one web lacked decorations). Finally, some of the spiders detected S. giraffa tapping the decorations or that had begun tapping the spiders and that had interrupted this behavior to tap the decorations. The data available suggest that, for S. giraffa, the decorations in these webs interfered with the process of locating the spiders. If further experiments corroborate this idea, this information would be in accord with Hingston’s (1927) hypothesis that web decorations can confuse spider predators.
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Bateman, Philip W., and Patricia A. Fleming. "The influence of web silk decorations on fleeing behaviour of Florida orb weaver spiders, Argiope florida (Aranaeidae)." Canadian Journal of Zoology 91, no. 7 (July 2013): 468–72. http://dx.doi.org/10.1139/cjz-2012-0312.
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Spider web silk decorations may (i) act to attract prey, (ii) be decoys for predators, and (iii) make the web visible to prevent larger animals from destroying them. To disentangle the last two hypotheses, we examined the fleeing response and flight initiation distance (FID) of the Florida orb weaver spider (Argiope florida Chamberlin and Ivie, 1944). Spiders were approached in one of two manners: (1) a “predatory” one mimicking a bird and (2) a “looming” approach mimicking the approach of a large animal. We predicted that if silk decorations had an antipredator function, then the extent of silk decoration would influence whether spiders fled from the predatory approach. However, if the function was primarily a signal to large animals, then all spiders would flee the looming approach, but FID would be influenced by the extent of silk decoration. We found no influence of silk decorations on fleeing behaviour and FID of spiders. Spider fleeing behaviour was, however, influenced by height of the web from the ground. The effects of web height might reflect an adaptive response to a more exposed position and therefore could support either of the two hypotheses tested; however, we have no evidence supporting the role of silk decorations on antipredator responses.
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Blackledge, Todd A., and Chad M. Eliason. "Functionally independent components of prey capture are architecturally constrained in spider orb webs." Biology Letters 3, no. 5 (July 3, 2007): 456–58. http://dx.doi.org/10.1098/rsbl.2007.0218.
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Evolutionary conflict in trait performance under different ecological contexts is common, but may also arise from functional coupling between traits operating within the same context. Orb webs first intercept and then retain insects long enough to be attacked by spiders. Improving either function increases prey capture and they are largely determined by different aspects of web architecture. We manipulated the mesh width of orbs to investigate its effect, along with web size, on prey capture by spiders and found that they functioned independently. Probability of prey capture increased with web size but was not affected by mesh width. Conversely, spiders on narrow-meshed webs were almost three times more likely to capture energetically profitable large insects, which demand greater prey retention. Yet, the two functions are still constrained during web spinning because increasing mesh width maximizes web size and hence interception, while retention is improved by decreasing mesh width because more silk adheres to insects. The architectural coupling between prey interception and retention has probably played a key role in both the macroevolution of orb web shape and the expression of plasticity in the spinning behaviours of spiders.
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Ellsworth, El, Yihan Li, Lenin D. Chari, Aidan Kron, and Sydney Moyo. "Tangled in a Web: Management Type and Vegetation Shape the Occurrence of Web-Building Spiders in Protected Areas." Insects 13, no. 12 (December 7, 2022): 1129. http://dx.doi.org/10.3390/insects13121129.
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Land management of parks and vegetation complexity can affect arthropod diversity and subsequently alter trophic interactions between predators and their prey. In this study, we examined spiders in five parks with varying management histories and intensities to determine whether certain spider species were associated with particular plants. We also determined whether web architecture influenced spider occurrence. Our results showed that humpbacked orb-weavers (Eustala anastera) were associated with an invasive plant, Chinese privet (Ligustrum sinense). This study revealed how invasive plants can potentially influence certain spider communities, as evidenced by this native spider species only occurring on invasive plants. Knowing more about spider populations—including species makeup and plants they populate—will give insights into how spider populations are dealing with various ecosystem changes. While we did not assess the effect of invasive plants on the behavior of spiders, it is possible that invasive species may not always be harmful to ecosystems; in the case of spiders, invasive plants may serve as a useful environment to live in. More studies are needed to ascertain whether invasive plants can have adverse effects on spider ecology in the long term.
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Adarsh, C. K., and P. O. Nameer. "A preliminary checklist of spiders (Araneae: Arachnida) in Chinnar Wildlife Sanctuary, Western Ghats, India." Journal of Threatened Taxa 8, no. 4 (April 26, 2016): 8703. http://dx.doi.org/10.11609/jott.2740.8.4.8703-8713.
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A preliminary study was conducted to document spider diversity in Chinnar Wildlife Sanctuary, Idukki District, Kerala State in southern India. The study was conducted from October to November 2012. A total of 101 species of spiders belonging to 65 genera from 29 families were identified from the sanctuary. This accounted for 6.98% of Indian spider species, 17.81% of Indian spider genera and 48.33% of the spider families of India. The dominant families were Lycosidae (11 species) and Araneidae (10). Two endemic genera of Indian spiders such as Annandaliella and Neoheterophrictus were found at Chinnar, each representing one species each, and belonging to the family Theraphosidae. A guild structure analysis of the spiders revealed seven feeding guilds such as orb weavers, stalkers, ground runners, foliage runners, sheet web builders, space web builders and ambushers.
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Davies, Mollie S., and Thomas Hesselberg. "The Use of Tuning Forks for Studying Behavioural Responses in Orb Web Spiders." Insects 13, no. 4 (April 9, 2022): 370. http://dx.doi.org/10.3390/insects13040370.
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Spiders and their webs are often used as model organisms to study a wide range of behaviours. However, these behavioural studies are often carried out in the laboratory, and the few field studies usually result in large amounts of video footage and subsequent labour-intensive data analysis. Thus, we aimed to devise a cost- and time-effective method for studying the behaviour of spiders in the field, using the now almost forgotten method of stimulating webs with tuning forks. Our study looked at the viability of using 256 Hz and 440 Hz tuning forks to stimulate, anti-predatory and predatory responses in the orb web spider Metellina segmentata, respectively. To assess the consistency of the behaviours produced, we compared these to direct mechanical stimulation with a metal wire. The results suggest that the tuning forks produce relatively consistent behaviours within and between two years in contrast to the metal wire. We furthermore found no significant effects of spider length or web area on spider reaction times. However, we found significant differences in reaction times between escape and prey capture behaviours, and between tuning forks and the wire. Thus, we demonstrated the potential of tuning forks to rapidly generate quantitative data in a field setting.
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Jakob, Elizabeth M., Adam H. Porter, and George W. Uetz. "Site fidelity and the costs of movement among territories: an example from colonial web-building spiders." Canadian Journal of Zoology 79, no. 11 (November 1, 2001): 2094–100. http://dx.doi.org/10.1139/z01-179.
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Species differ in whether they exhibit strong site fidelity or move readily among sites. To understand the adaptive significance of site fidelity it is necessary to measure the cost of relocating to new sites, but this is very difficult with most species because it entails following individuals during the entire course of their transition. We studied the colonial web-building spider Metepeira incrassata (Araneae: Araneidae), which defends individual orb webs within a large, shared frame web. Colonies are heterogeneous habitats, with more prey but also more predators at the periphery of the colony relative to the central core. We measured relocation costs in this species by breaking them into the following components, (i) searching costs, (ii) establishment costs, and (iii) lost-opportunities costs, or the potential benefits of alternative behaviors that an animal might engage in if it were not relocating. We observed spiders that were in the process of establishing their orb webs at the start of the foraging day and conducted experiments to examine the costs of relocation by transferring spiders between locations within the colony. Transferred spiders had more fights with conspecifics than non-transferred spiders did, and the number of fights was positively correlated with the distance moved. However, searching and establishment costs seem unimportant, as individuals moving within their territories were as active as individuals moving to new sites. Transferred spiders faced greater lost-opportunities costs in the form of time spent on prey-capture orbs, as they significantly delayed orb construction. Lost-opportunities costs seem to be the most important component of relocation costs in this species and are likely to be generally important among species. This study is one of the few to document movement costs through direct observation.
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Vollrath, Fritz, and Thiemo Krink. "Spider webs inspiring soft robotics." Journal of The Royal Society Interface 17, no. 172 (November 2020): 20200569. http://dx.doi.org/10.1098/rsif.2020.0569.
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In soft robotics, bio-inspiration ranges from hard- to software. Orb web spiders provide excellent examples for both. Adapted sensors on their legs may use morphological computing to fine-tune feedback loops that supervise the handling and accurate placement of silk threads. The spider's webs embody the decision rules of a complex behaviour that relies on navigation and piloting laid down in silk by behaviour charting inherited rules. Analytical studies of real spiders allow the modelling of path-finding construction rules optimized in evolutionary algorithms. We propose that deconstructing spiders and unravelling webs may lead to adaptable robots able to invent and construct complex novel structures using relatively simple rules of thumb.
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HARMER, AARON M. T., and VOLKER W. FRAMENAU. "Telaprocera (Araneae: Araneidae), a new genus of Australian orb-web spiders with highly elongated webs." Zootaxa 1956, no. 1 (December 5, 2008): 59–80. http://dx.doi.org/10.11646/zootaxa.1956.1.2.
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A new genus of orb-web spider (Araneidae Simon), Telaprocera gen. nov., including two new species, T. maudae sp. nov. (type species) and T. joanae sp. nov., are described. Telaprocera gen. nov. differs from all other araneid genera by the presence of a dorsal keel on the male cymbium. The known range of Telaprocera maudae sp. nov. is limited to the east coast of Australia, from far northern Queensland to central New South Wales. The spiders are found in closed canopy rainforest and adults can be found year round. Telaprocera joanae sp. nov. has been found from central coastal Queensland to far eastern Victoria. They occur in similar habitats, with similar phenology, as T. maudae sp. nov. Both species build highly elongated orb-webs known as ladder-webs. A variety of phylogenetic analyses based on an updated morphological data matrix for orb-web spiders did not provide a conclusive placement of Telaprocera gen. nov. within the Araneidae. Equally weighted analysis placed the genus as sister to Kaira O. P.-Cambridge and Metepeira F. O. P.Cambridge combined. Strong downweighting of homoplasious characters placed the genus as sister taxon to the traditional Argiopinae Simon. The uncertain phylogenetic position of Telaprocera gen. nov. may reflect the insufficient knowledge of the morphology of Australian taxa—taxa that may possess characters previously not considered in phylogenetic analyses of the Araneidae.
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Gomes, Dylan G. E. "Orb-weaving spiders are fewer but larger and catch more prey in lit bridge panels from a natural artificial light experiment." PeerJ 8 (March 17, 2020): e8808. http://dx.doi.org/10.7717/peerj.8808.
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Artificial light at night is rapidly changing the sensory world. While evidence is accumulating for how insects are affected, it is not clear how this impacts higher trophic levels that feed on insect communities. Spiders are important insect predators that have recently been shown to have increased abundance in urban areas, but have shown mixed responses to artificial light. On a single bridge with alternating artificially lit and unlit sections, I measured changes in the orb-weaving spider Larinioides sclopetarius (Araneidae) web abundance, web-building behavior, prey-capture, and body condition. In artificially lit conditions, spiders caught more prey with smaller webs, and had higher body conditions. However, there were fewer spiders with active webs in those lit areas. This suggests that either spiders were not taking advantage of an ecological insect trap, perhaps due to an increased risk of becoming prey themselves, or were satiated, and thus not as active within these habitats. The results from this natural experiment may have important consequences for both insects and spiders in urban areas under artificial lighting conditions.
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Diaz, Candido, and John H. Long. "Behavior and Bioadhesives: How Bolas Spiders, Mastophora hutchinsoni, Catch Moths." Insects 13, no. 12 (December 16, 2022): 1166. http://dx.doi.org/10.3390/insects13121166.
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Spiders use various combinations of silks, adhesives, and behaviors to ensnare and trap prey. A common but difficult to catch prey in most spider habitats are moths. They easily escape typical orb-webs because their bodies are covered in sacrificial scales that flake off when in contact with the web’s adhesives. This defense is defeated by spiders of the sub-family of Cyrtarachninae, moth-catching specialists who combine changes in orb-web structure, predatory behavior, and chemistry of the aggregate glue placed in those webs. The most extreme changes in web structure are shown by bolas spiders, who create a solitary capture strand containing only one or two glue droplets at the end of a single thread. They prey on male moths by releasing pheromones to draw them within range of their bolas, which they flick to ensnare the moth. We used a high-speed video camera to capture the behavior of the bolas spider Mastophora hutchinsoni. We calculated the kinematics of spiders and moths in the wild to model the physical and mechanical properties of the bolas during prey capture, the behavior of the moth, and how these factors lead to successful prey capture. We created a numerical model to explain the mechanical behavior of the bolas silk during prey capture. Our kinematic analysis shows that the material properties of the aggregate glue bolas of M. hutchinsoni are distinct from that of the other previously analyzed moth-specialist, Cyrtarachne akirai. The spring-like behavior of the M. hutchinsoni bolas suggests it spins a thicker liquid.
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Eberhard, William G. "Modular patterns in behavioural evolution: webs derived from orbs." Behaviour 155, no. 6 (2018): 531–66. http://dx.doi.org/10.1163/1568539x-00003502.
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Abstract Imperfect knowledge of ancestral behaviour often hampers tracing behavioural evolution. This limitation is reduced in orb weaving spiders, because spider orb web construction behaviour and the cues used by modern orb-weavers are well-studied and highly conserved. Several species in orb-weaving families build non-orb webs that are clearly derived from orbs, allowing transitions from ancestral to modern behaviours to be described with high confidence. Three major patterns of general evolutionary significance were found in 69 phylogenetically independent transitions in 15 groups in 8 families: ancestral traits were often maintained as units; the most frequent of the eight different types of ancestral trait change was transfer of an ancestral behaviour to a new context; and ‘new’ traits that had no clear homology with ancestral traits were also common. Changes occurred in all major stages of orb construction. This may be the most extensive summary of evolutionary transitions in behaviour yet compiled.
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Dimitrov, Dimitar, Lara Lopardo, Gonzalo Giribet, Miquel A. Arnedo, Fernando Álvarez-Padilla, and Gustavo Hormiga. "Tangled in a sparse spider web: single origin of orb weavers and their spinning work unravelled by denser taxonomic sampling." Proceedings of the Royal Society B: Biological Sciences 279, no. 1732 (November 2, 2011): 1341–50. http://dx.doi.org/10.1098/rspb.2011.2011.
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In order to study the tempo and the mode of spider orb web evolution and diversification, we conducted a phylogenetic analysis using six genetic markers along with a comprehensive taxon sample. The present analyses are the first to recover the monophyly of orb-weaving spiders based solely on DNA sequence data and an extensive taxon sample. We present the first dated orb weaver phylogeny. Our results suggest that orb weavers appeared by the Middle Triassic and underwent a rapid diversification during the end of the Triassic and Early Jurassic. By the second half of the Jurassic, most of the extant orb-weaving families and web designs were already present. The processes that may have given origin to this diversification of lineages and web architectures are discussed. A combination of biotic factors, such as key innovations in web design and silk composition, as well as abiotic environmental changes, may have played important roles in the diversification of orb weavers. Our analyses also show that increased taxon sampling density in both ingroups and outgroups greatly improves phylogenetic accuracy even when extensive data are missing. This effect is particularly important when addition of character data improves gene overlap.
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Willmott, Nikolas J., Jessica Henneken, Caitlin J. Selleck, and Therésa M. Jones. "Artificial light at night alters life history in a nocturnal orb-web spider." PeerJ 6 (October 9, 2018): e5599. http://dx.doi.org/10.7717/peerj.5599.
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The prevalence of artificial light at night (ALAN) is increasing rapidly around the world. The potential physiological costs of this night lighting are often evident in life history shifts. We investigated the effects of chronic night-time exposure to ecologically relevant levels of LED lighting on the life history traits of the nocturnal Australian garden orb-web spider (Eriophora biapicata). We reared spiders under a 12-h day and either a 12-h natural darkness (∼0 lux) or a 12-h dim light (∼20 lux) night and assessed juvenile development, growth and mortality, and adult reproductive success and survival. We found that exposure to ALAN accelerated juvenile development, resulting in spiders progressing through fewer moults, and maturing earlier and at a smaller size. There was a significant increase in daily juvenile mortality for spiders reared under 20 lux, but the earlier maturation resulted in a comparable number of 0 lux and 20 lux spiders reaching maturity. Exposure to ALAN also considerably reduced the number of eggs produced by females, and this was largely associated with ALAN-induced reductions in body size. Despite previous observations of increased fitness for some orb-web spiders in urban areas and near night lighting, it appears that exposure to artificial night lighting may lead to considerable developmental costs. Future research will need to consider the detrimental effects of ALAN combined with foraging benefits when studying nocturnal insectivores that forage around artificial lights.
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Su, Isabelle, Zhao Qin, Tomás Saraceno, Adrian Krell, Roland Mühlethaler, Ally Bisshop, and Markus J. Buehler. "Imaging and analysis of a three-dimensional spider web architecture." Journal of The Royal Society Interface 15, no. 146 (September 2018): 20180193. http://dx.doi.org/10.1098/rsif.2018.0193.
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Spiders are abundantly found in nature and most ecosystems, making up more than 47 000 species. This ecological success is in part due to the exceptional mechanics of the spider web, with its strength, toughness, elasticity and robustness, which originate from its hierarchical structures all the way from sequence design to web architecture. It is a unique example in nature of high-performance material design. In particular, to survive in different environments, spiders have optimized and adapted their web architecture by providing housing, protection, and an efficient tool for catching prey. The most studied web in literature is the two-dimensional (2D) orb web, which is composed of radial and spiral threads. However, only 10% of spider species are orb-web weavers, and three-dimensional (3D) webs, such as funnel, sheet or cobwebs, are much more abundant in nature. The complex spatial network and microscale size of silk fibres are significant challenges towards determining the topology of 3D webs, and only a limited number of previous studies have attempted to quantify their structure and properties. Here, we focus on developing an innovative experimental method to directly capture the complete digital 3D spider web architecture with micron scale resolution. We built an automatic segmentation and scanning platform to obtain high-resolution 2D images of individual cross-sections of the web that were illuminated by a sheet laser. We then developed image processing algorithms to reconstruct the digital 3D fibrous network by analysing the 2D images. This digital network provides a model that contains all of the structural and topological features of the porous regions of a 3D web with high fidelity, and when combined with a mechanical model of silk materials, will allow us to directly simulate and predict the mechanical response of a realistic 3D web under mechanical loads. Our work provides a practical tool to capture the architecture of sophisticated 3D webs, and could lead to studies of the relation between architecture, material and biological functions for numerous 3D spider web applications.
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Rao, Dinesh, Ken Cheng, and Marie E. Herberstein. "A natural history of web decorations in the St Andrew's Cross spider (Argiope keyserlingi)." Australian Journal of Zoology 55, no. 1 (2007): 9. http://dx.doi.org/10.1071/zo06010.
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A long-running debate in the spider literature concerns the function of the extra silk decorations in some spider webs. These decorations are appended to the web and constitute a highly visible signal, which is inconsistent with the trend towards web invisibility. Despite the sustained attention of researchers, the exact function of these decorations is yet to be understood. While most studies have focussed on testing particular hypotheses, there has been a dearth of natural history data regarding web decorations in field conditions. In this study we present baseline data regarding the influence of seasonality, microhabitat characteristics and ecology on the presence of web decorations in an Australian orb web spider, Argiope keyserlingi. In particular, we show that there is preference among spiders to build their webs between bushes and to face the south-east, but this preference does not influence decoration building.
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Garrison, Nicole L., Juanita Rodriguez, Ingi Agnarsson, Jonathan A. Coddington, Charles E. Griswold, Christopher A. Hamilton, Marshal Hedin, Kevin M. Kocot, Joel M. Ledford, and Jason E. Bond. "Spider phylogenomics: untangling the Spider Tree of Life." PeerJ 4 (February 23, 2016): e1719. http://dx.doi.org/10.7717/peerj.1719.
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Spiders (Order Araneae) are massively abundant generalist arthropod predators that are found in nearly every ecosystem on the planet and have persisted for over 380 million years. Spiders have long served as evolutionary models for studying complex mating and web spinning behaviors, key innovation and adaptive radiation hypotheses, and have been inspiration for important theories like sexual selection by female choice. Unfortunately, past major attempts to reconstruct spider phylogeny typically employing the “usual suspect” genes have been unable to produce a well-supported phylogenetic framework for the entire order. To further resolve spider evolutionary relationships we have assembled a transcriptome-based data set comprising 70 ingroup spider taxa. Using maximum likelihood and shortcut coalescence-based approaches, we analyze eight data sets, the largest of which contains 3,398 gene regions and 696,652 amino acid sites forming the largest phylogenomic analysis of spider relationships produced to date. Contrary to long held beliefs that the orb web is the crowning achievement of spider evolution, ancestral state reconstructions of web type support a phylogenetically ancient origin of the orb web, and diversification analyses show that the mostly ground-dwelling, web-less RTA clade diversified faster than orb weavers. Consistent with molecular dating estimates we report herein, this may reflect a major increase in biomass of non-flying insects during the Cretaceous Terrestrial Revolution 125–90 million years ago favoring diversification of spiders that feed on cursorial rather than flying prey. Our results also have major implications for our understanding of spider systematics. Phylogenomic analyses corroborate several well-accepted high level groupings: Opisthothele, Mygalomorphae, Atypoidina, Avicularoidea, Theraphosoidina, Araneomorphae, Entelegynae, Araneoidea, the RTA clade, Dionycha and the Lycosoidea. Alternatively, our results challenge the monophyly of Eresoidea, Orbiculariae, and Deinopoidea. The composition of the major paleocribellate and neocribellate clades, the basal divisions of Araneomorphae, appear to be falsified. Traditional Haplogynae is in need of revision, as our findings appear to support the newly conceived concept of Synspermiata. The sister pairing of filistatids with hypochilids implies that some peculiar features of each family may in fact be synapomorphic for the pair. Leptonetids now are seen as a possible sister group to the Entelegynae, illustrating possible intermediates in the evolution of the more complex entelegyne genitalic condition, spinning organs and respiratory organs.
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Mortimer, B., A. Soler, C. R. Siviour, R. Zaera, and F. Vollrath. "Tuning the instrument: sonic properties in the spider's web." Journal of The Royal Society Interface 13, no. 122 (September 2016): 20160341. http://dx.doi.org/10.1098/rsif.2016.0341.
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Spider orb webs are multifunctional, acting to absorb prey impact energy and transmit vibratory information to the spider. This paper explores the links between silk material properties, propagation of vibrations within webs and the ability of the spider to control and balance web function. Combining experimental and modelling approaches, we contrast transverse and longitudinal wave propagation in the web. It emerged that both transverse and longitudinal wave amplitude in the web can be adjusted through changes in web tension and dragline silk stiffness, i.e. properties that can be controlled by the spider. In particular, we propose that dragline silk supercontraction may have evolved as a control mechanism for these multifunctional fibres. The various degrees of active influence on web engineering reveals the extraordinary ability of spiders to shape the physical properties of their self-made materials and architectures to affect biological functionality, balancing trade-offs between structural and sensory functions.
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Diaz, Candido, and John Roff. "Mechanics of the Prey Capture Technique of the South African Grassland Bolas Spider, Cladomelea akermani." Insects 13, no. 12 (December 5, 2022): 1118. http://dx.doi.org/10.3390/insects13121118.
Full textAbstract:
Spiders use various combinations of silks, adhesives, and behaviors to ensnare prey. One common but difficult-to-catch prey is moths. They easily escape typical orb-webs because their bodies are covered in tiny sacrificial scales that flake off when in contact with the web’s adhesives. This defense is defeated by spiders of the sub-family of Cyrtarachninae—moth-catching specialists who combine changes in orb-web structure, predatory behavior, and chemistry of the aggregate glue placed in those webs. The most extreme changes in web structure are shown by the bolas spiders which create only one or two glue droplets at the end of a single thread. They prey on male moths by releasing pheromones to draw them close. Here, we confirm the hypothesis that the spinning behavior of the spider is directly used to spin its glue droplets using a high-speed video camera to observe the captured behavior of the bolas spider Cladomelea akermani as it actively spins its body and bolas. We use the kinematics of the spider and bolas to begin to quantify and model the physical and mechanical properties of the bolas during prey capture. We then examine why this species chooses to spin its body, an energetically costly behavior, during prey capture. We test the hypothesis that spinning helps to spread pheromones by creating a computational fluid dynamics model of airflow within an open field and comparing it to that of airflow within a tree, a common environment for bolas spiders that do not spin. Spinning in an open environment creates turbulent air, spreading pheromones further and creating a pocket of pheromones. Conversely, spinning within a tree does little to affect the natural airflow.
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Harmer, Aaron M. T. "Elongated orb-webs of Australian ladder-web spiders (Araneidae: Telaprocera) and the significance of orb-web elongation." Journal of Ethology 27, no. 3 (January 22, 2009): 453–60. http://dx.doi.org/10.1007/s10164-008-0142-8.
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Herberstein, M. E. "Foraging behaviour in orb-web spiders (Araneidae): do web decorations increase prey capture success in Argiope keyserlingi Karsch, 1878?" Australian Journal of Zoology 48, no. 2 (2000): 217. http://dx.doi.org/10.1071/zo00007.
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Orb web spiders in the genus Argiope attach highly visible silk bands called decorations or stabilimenta to their webs. Two different hypotheses regarding the function of these structures were investigated in the field using Argiope keyserlingi: prey attraction and anti-predatory device. The first hypothesis suggests that web decorations attract prey to the web, and webs carrying decorations will capture more prey than those without. A field census of prey capture showed that webs adorned with more decorative bands indeed captured more but similarly sized prey per hour compared with webs carrying fewer decorations. Web height or web size, however, were not related to the rate of prey capture. This pattern was confirmed by a paired comparison of prey-capture rates within individuals that increased or decreased the number of decorative bands on consecutive days. Individuals that used more decorations also captured more prey compared with days when they spun fewer decorations. The second hypothesis suggests that these structures function as anti-predatory devices and, consequently, spiders on decorated webs benefit from a lower rate of mortality than spiders on undecorated webs. A census of the mortality rates of spiders over 19 days revealed that spiders did not disappear from undecorated webs more frequently than from decorated webs. Consequently, the idea that web decorations act as anti-predatory devices in A. keyserlingi was not supported.
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Reshma Solanki, Manju Siliwal, and Dolly Kumar. "A preliminary checklist of spiders (Araneae: Arachnida) in Jambughoda Wildlife Sanctuary, Panchmahal District, Gujarat, India." Journal of Threatened Taxa 12, no. 11 (August 26, 2020): 16576–96. http://dx.doi.org/10.11609/jott.3094.12.11.16576-16596.
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Studies relating to spiders in Gujarat have been sporadic and most of the spider documentation have been done from agriculture fields, wetlands and few from protected areas. One such undocumented area was Jambughoda Wildlife Sanctuary, Panchmahal District, Gujarat. Therefore, a study to document the spider diversity was carried out in Jambughoda Wildlife Sanctuary from July 2012 to October 2015. A combination of four sampling methods namely, belt transect along with hand-pick method, pitfall sampling, vegetation beating and leaf litter extraction were used for collection of spiders from different strata. During the study, a total of 138 species belonging to 90 genera and 29 families were recorded from the study area. Of which, 21 species and 17 genera were recorded for the first time from Gujarat State. The theridiid genus Cephalobares O. Pickard-Cambridge, 1870 was recorded for the first time from India. The families Araneidae, Salticidae, Theridiidae and Oxyopidae were found to be dominant in the area. We recognized seven feeding guilds namely ambushers, foliage runners, ground runners, orb weavers, sheet web-builders, space web-builders and stalkers. Amongst these, orb-weavers, stalkers and ground runners were dominant. This documentation, however, forms the baseline information for spiders of Jambughoda WLS, suggesting the great diversity of the spider fauna in this protected area, which can be further explored.
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Champion de Crespigny, F. E., M. E. Herberstein, and M. A. Elgar. "The effect of predator-prey distance and prey profitability on the attack behaviour of the orb-web spider Argiope keyserlingi (Araneidae)." Australian Journal of Zoology 49, no. 3 (2001): 213. http://dx.doi.org/10.1071/zo00074.
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The foraging behaviour of central-place foragers is thought to be strongly influenced by the distance between the forager and the food source (predator–prey distance). Orb-web spiders are uniquely suited for investigating this idea because they make active foraging decisions towards prey entangled in the web, and they define the dimensions of their foraging arena when they construct the web. Here we manipulate the physiological condition of Argiope keyserlingi and present the spiders with prey of varying quality, in terms of size and accessibility (location within the web and distance from the spider). We found that these spiders adjust their foraging behaviour primarily in response to their physiological condition but, in contrast to other central-place foragers, are indiscriminant of predator–prey distance or the likelihood of escape of the prey. We suggest that these factors are incorporated into the design of the web, and thus increase foraging success through efficient web design.
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Hesselberg, Thomas. "Ontogenetic Changes in Web Design in Two Orb-Web Spiders." Ethology 116, no. 6 (April 5, 2010): 535–45. http://dx.doi.org/10.1111/j.1439-0310.2010.01760.x.
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Adarsh, C. K., and P. O. Nameer. "Spiders of Kerala Agricultural University Campus, Thrissur, Kerala, India." Journal of Threatened Taxa 7, no. 15 (December 26, 2015): 8288. http://dx.doi.org/10.11609/jott.2468.7.15.8288-8295.
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<p>A total of 86 species of spiders belonging to 56 genera of 20 families have been recorded from the Kerala Agricultural University (KAU) campus, Thrissur, Kerala, southern India. This represents 5.1% of the total spiders’ species and 33.33% of the total families of spiders recorded in India. The dominant spider family at KAU campus is Araneidae with 18 species of nine genera. Salticidae is represented by 14 species of 13 genera. Out of 252 endemic spiders of India, 16 have been reported from KAU campus. Guild structure analysis shows spiders belonging to seven types of feeding guilds present in KAU campus. Orb-web builders are the dominant feeding guild accounting for 34%, followed by stalkers (22%), ground runners (20%), ambushers (8%), scattered line weavers (8%), foliage runners (7%) and sheet-web builders (1%).</p><div> </div>
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Joseph, Linta, and K. Sunil Jose. "Checklist of spiders from Vallakadavu range of Western Ghats, Kerala, India." ENTOMON 47, no. 3 (September 30, 2022): 341–44. http://dx.doi.org/10.33307/entomon.v47i3.774.
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In the preliminary study conducted to document the spider fauna in Vallakadavu range, Idukki district, Kerala, a total of 33 species of spiders belonging to 29 genera from 12 families were recorded. Among the 12 families recorded, Araneidae was the most predominant with orb web weavers. From the guild analysis, the recorded families were categorized into seven principle types of web patterns.The study extends the range of Poecilotheriastriata Pocock, 1895 in the state to the east.
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Craig, Catherine L. "Alternative Foraging Modes of Orb Web Weaving Spiders." Biotropica 21, no. 3 (September 1989): 257. http://dx.doi.org/10.2307/2388653.
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Selden, Paul A. "Orb-web weaving spiders in the early Cretaceous." Nature 340, no. 6236 (August 1989): 711–13. http://dx.doi.org/10.1038/340711a0.
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Champion de Crespigny, Fleur E., Marie E. Herberstein, and Mark A. Elgar. "Food caching in orb-web spiders (Araneae: Araneoidea)." Naturwissenschaften 88, no. 1 (January 2001): 42–45. http://dx.doi.org/10.1007/s001140000194.
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Corey, Tyler B., Earl Agpawa, and Eileen A. Hebets. "Spiders (Araneae) Collected as Prey by the Mud-Dauber Wasps Sceliphron caementarium and Chalybion californicum (Hymenoptera: Sphecidae) in Southeastern Nebraska." Journal of Entomological Science 56, no. 2 (April 1, 2021): 123–40. http://dx.doi.org/10.18474/0749-8004-56.2.123.
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Abstract Predator diets represent a potential interaction between local prey availability, prey antipredator defenses, and predator foraging behavior. Female spider-specialist mud-dauber wasps (Hymenoptera: Sphecidae) collect spiders and provision them intact, but paralyzed, to their developing larvae, providing a unique means of quantifying the diversity and abundance of prey that they capture. Mud-dauber wasps are hypothesized to be a major source of selection on antipredator defenses in web-building spiders, and the spiny and thickened abdomens of female spiny orb-weaving spiders (Araneae: Araneidae) are hypothesized to function as antiwasp defenses. We inventoried spider prey from nests of the mud-dauber wasps Sceliphron caementarium (Drury) and Chalybion californicum (Saussure), and surveyed for spider fauna in areas surrounding nest collection sites, to specifically investigate if the spiny orb-weaver Micrathena gracilis (Walckenaer) was collected as prey by these wasps. We collected nests from six sites in southeastern Nebraska from two regions that we classify based on habitat—a forest corridor and agricultural land. We collected 761 intact spider prey from 87 nests and identified them to the family level. None of these spiders were M. gracilis. Micrathena gracilis were rare in faunal surveys on agricultural land and, surprisingly, absent in forest corridor surveys. Mud-dauber wasps were more common; we collected more spiders on agricultural land than in the forest corridor. We propose that in agricultural landscapes, the lack of certain spiders in mud-dauber wasp nests is driven by habitat use differences between predators and prey rather than physical antipredator defenses.
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Harmer, Aaron M. T., Todd A. Blackledge, Joshua S. Madin, and Marie E. Herberstein. "High-performance spider webs: integrating biomechanics, ecology and behaviour." Journal of The Royal Society Interface 8, no. 57 (November 2010): 457–71. http://dx.doi.org/10.1098/rsif.2010.0454.
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Spider silks exhibit remarkable properties, surpassing most natural and synthetic materials in both strength and toughness. Orb-web spider dragline silk is the focus of intense research by material scientists attempting to mimic these naturally produced fibres. However, biomechanical research on spider silks is often removed from the context of web ecology and spider foraging behaviour. Similarly, evolutionary and ecological research on spiders rarely considers the significance of silk properties. Here, we highlight the critical need to integrate biomechanical and ecological perspectives on spider silks to generate a better understanding of (i) how silk biomechanics and web architectures interacted to influence spider web evolution along different structural pathways, and (ii) how silks function in an ecological context, which may identify novel silk applications. An integrative, mechanistic approach to understanding silk and web function, as well as the selective pressures driving their evolution, will help uncover the potential impacts of environmental change and species invasions (of both spiders and prey) on spider success. Integrating these fields will also allow us to take advantage of the remarkable properties of spider silks, expanding the range of possible silk applications from single threads to two- and three-dimensional thread networks.
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Prajapati, Dhruv A., Krunal R. Patel, Sandeep B. Munjpara, Shiva S. Chettiar, and Devendrasinh D. Jhala. "Spiders (Arachnida: Araneae) of Gujarat University Campus, Ahmedabad, India with additional description of Eilica tikaderi (Platnick, 1976)." Journal of Threatened Taxa 8, no. 11 (September 26, 2016): 9327. http://dx.doi.org/10.11609/jott.1835.8.11.9327-9333.
Full textAbstract:
We report a checklist of spiders based on a survey made from August 2013 to July 2014 in Gujarat University Campus, an urban area located in the middle of Ahmadabad City, Gujarat State. A total of 77 species of spiders belonging to 53 genera and 20 families of spiders were recorded from the study area represented by 31.74% of the total 63 families reported from India. Salticidae was found to be the most dominant family with 18 species from 14 genera. Guild structure analysis revealed six feeding guilds, namely stalkers, orb-web builders, space-web builders, ambushers, foliage hunters and ground runners. Stalkers and orb-web builders were the most dominant feeding guilds representing 28.58% and 20.78% respectively among all studied guilds. Species Eilica tikaderi (Platnick, 1976) is reported for the first time from Gujarat with additional description and detailed genitalic illustrations.