Comparative Growth and Development of Spiders Reared on Live and Dead Prey

Yu Peng,Shaolan Gui,Huping Qiao,Grant C Hose,Fan Zhang,Joseph Clifton Dickens

doi:10.1371/journal.pone.0083663

Abstract

Scavenging (feeding on dead prey) has been demonstrated across a number of spider families, yet the implications of feeding on dead prey for the growth and development of individuals and population is unknown. In this study we compare the growth, development, and predatory activity of two species of spiders that were fed on live and dead prey. Pardosa astrigera (Lycosidae) and Hylyphantes graminicola (Lyniphiidae) were fed live or dead fruit flies, Drosophila melanogaster. The survival of P. astrigera and H. graminicola was not affected by prey type. The duration of late instars of P. astrigera fed dead prey were longer and mature spiders had less protein content than those fed live prey, whereas there were no differences in the rate of H. graminicola development, but the mass of mature spiders fed dead prey was greater than those fed live prey. Predation rates by P. astrigera did not differ between the two prey types, but H. graminicola had a higher rate of predation on dead than alive prey, presumably because the dead flies were easier to catch and handle. Overall, the growth, development and reproduction of H. graminicola reared with dead flies was better than those reared on live flies, yet for the larger P. astrigera, dead prey may suit smaller instars but mature spiders may be best maintained with live prey. We have clearly demonstrated that dead prey may be suitable for rearing spiders, although the success of the spiders fed such prey appears size- and species specific.

Highlights

As obligate predators, spiders play important roles in terrestrial food webs but are susceptible to environmental changes either directly or via changes in prey populations
With difficulties in maintaining live prey populations, we examined the potential for using dead prey as a substitute, such that laboratory populations can be reared in a less labor intensive manor
This study demonstrates that feeding on solely either live or dead prey can influence the growth and development of spiders but that the response is species specific

Summary

Introduction

Spiders play important roles in terrestrial food webs but are susceptible to environmental changes either directly or via changes in prey populations. Spiders have a long history of beneficial uses for humans, including medicinal use [2], and more recently as sources of antimicrobial compounds [3,4]. For these benefits, the laboratory rearing of live spiders is necessary to achieve a critical population size and biomass. While spiders are generally known for feeding on other active arthropods, some eat a variety of non-moving prey such as the eggs of insects or other spiders [8,9,10,11], and non-prey foods, such as honeydew, pollen, nectar [12,13], and plants [14,15,16]

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Results

Conclusion