Effect of prey size on growth of newly emerged crab spiderlings Misumena vatia

Abstract

Abstract Capturing unusually profitable prey early in life potentially enhances one's future fecundity and survival. Newly emerged crab spiderlings Misumena vatia (Araneae: Thomisidae) occasionally capture prey that greatly exceed them in size. I attempted to evaluate what if any long-term advantage these kills provided by presenting naive, just-emerged spiderlings with syrphid flies Toxomerus marginatus that exceeded the initial mass of the spiderlings six-fold, a prey that the spiderlings occasionally captured in the field. A second group of spiderlings received a single syrphid initially and subsequently a single fruit fly Drosophila melanogaster every other day, and a control group received a fruit fly every other day. The few spiderlings that regularly captured the syrphids gained significantly more mass than the other groups. Individuals taking an initial syrphid and then fruit flies did not gain more mass than controls fed on solely on fruit flies. Neither did a group of spiderlings followed in the...