Cuticular compounds inhibit cannibalism of early‐instar spiderlings by pulli‐carrying Pardosa pseudoannulata females

Abstract

Cannibalism is common in spiders. Wolf spider (Lycosidae) females, which exhibit extensive maternal care, have been reported to cannibalize less when they are carrying egg sacs and juveniles. In a laboratory experiment, we demonstrated that cannibalism of early‐instar spiderlings (EIS) by a wolf spider (Pardosa pseudoannulata) mother was almost completely inhibited when she was carrying spiderlings. Compared with virgin and mated‐females, mother spiders tolerated more and predated fewer spiderlings, including gregarious pulli and newly dispersed spiderlings (NDS). Cannibalism of EIS by females during their reproductive period exhibited a V‐shaped pattern, with a gradual decrease from the egg sac‐carrying to pulli‐carrying (PC) stage, and a recovery from the PC stage to post‐reproductive (PR) stage. Notably, there was 0 cannibalism at the PC stage. PC females exhibited no interest in pulli, while PR females were attracted to and predated pulli and NDS as they did their natural prey, Nilaparvata lugens. Interestingly, PC females captured and released NDS in a foraging assay, although attraction was observed from olfactometer measurements. PC mothers possessed a cuticular volatile profile that was closer to that of pulli and NDS than to that of PR females. Moreover, NDS cuticular extract provoked an electrophysiological response in legs of PC females. Therefore, cuticular compound‐mediated chemical communication may be involved in inhibiting cannibalism of EIS by spider mothers, and especially in eliminating cannibalism by PC mothers. Future studies will aim to characterize the specific cuticular compounds and chemoreception mechanism in females, which will facilitate our understanding of intraspecific recognition and cannibalism in spiders.

EcR/USP-1-mediated ecdysteroid signaling regulates wolf spider (<i>Pardosa pseudoannulata</i>) development and reproduction

“…Some arthropods, such as spiders, provide extensive maternal attention to protect and improve the success of their offspring ( Yip & Rayor, 2014 ), including egg sac construction and care and juvenile spiderling care ( Ruhland et al, 2016b ). For example, web weaving spiders attach their egg sacs to their webs, while Lycosidae females carry egg sacs in their spinnerets and newly emerged juveniles on their notum ( Yang et al, 2018 ; Yu et al, 2022 ). Egg care is effective for protecting offspring from predators, parasites, and adverse environments ( Iida & Fujisaki, 2005 ; Ruhland et al, 2016a ; Vieira & Romero, 2008 ).…”

“…Pardosa pseudoannulata , a wolf spider species that preys on various pest insects in agricultural fields, also displays meticulous maternal care. After egg sac production, the females carry their egg sacs for about 15 d until hatching and then carry the newly emerged spiderlings for 4–5 d before dispersal ( Yu et al, 2022 ). Once they start mating, P. pseudoannulata females can produce up to five egg sacs in their lifetime ( Yang et al, 2018 ).…”

Pardosa pseudoannulata mother adopts a compensatory strategy for reproduction deficiency resulting from the suppression of EcR/USP-1-mediated ecdysteroid signaling

“…Maternal care in spiders include eggsac construction, eggsac care, and juvenile spiderling care (Ruhland et al 2016b). For example, the web-weaver spiders attach their eggsac to the web, while Lycosidae females carry their eggsac via spinnerets, and then carry the juveniles emerging from eggsac on notum (Yang et al 2018;Yu et al 2022). Egg brooding is effective for offspring protection against predators, parasites, and adverse environment (Iida and Fujisaki 2005;Ruhland et al 2016a; Vieira and Romero 2008).…”

“…Pardosa pseudoannulata is a predatory wolf spider against various insect pests in elds and exhibits meticulous maternal care to its offsprings. After the eggsac production, the female spiders carry their eggsacs for about 15 d until the juvenile spiderling emergence, and later carry the new-emerged spiderlings for about 4.6 d before their dispersal (Yu et al 2022). Although cannibalism is common in the spider, the females do not acutely prey the new-emerged spiderlings during maternal care (Yu et al 2022).…”

“…After the eggsac production, the female spiders carry their eggsacs for about 15 d until the juvenile spiderling emergence, and later carry the new-emerged spiderlings for about 4.6 d before their dispersal (Yu et al 2022). Although cannibalism is common in the spider, the females do not acutely prey the new-emerged spiderlings during maternal care (Yu et al 2022). P. pseudoannulata females can produce ve eggsacs at most in the life once mating (Yang et al 2018), so the maternal care is alternate with the cannibalism.…”