Flower choice by naive young crab spiders and the effect of subsequent experience

Initial responses of naive individuals to critical environmental stimuli pr ovide important information about the innate contribution to behaviour, and subsequent responses to the same stimuli may show the role of experience i n mediating those initial responses. To test the role of these factors, I m easured initial patch choices and giving-up responses of just-emerged, naiv e, second-instar crab spiders, Misumena vatia, on several hunting sites the y encountered after leaving their natal nests. In follow-up tests I measure d the effects of these experiences on subsequent patch choice decisions. Th e choice of hunting sites is a vital decision at all stages of the life cyc le for sit-and-wait predators such as Misumena. In their initial tests thes e spiderlings remained more frequently on goldenrod (Solidago spp.) flowers than on green or yellow goldenrod buds, a preference they retained through tests run on 5 consecutive days. Individuals on green and yellow buds shif ted sites more quickly and frequently than those from flowers, and made mos t of these moves to flowers, which attracted many more prey than did buds. These differences were not affected by age, energetic condition, or loss of information over the period of the experiment. Once spiderlings moved from buds, they showed a high, increasing tendency to move from buds in subsequ ent runs, those from flowers showed a consistently law tendency. These resu lts suggest that spiderlings retain their innate behavioural patterns throu gh the second instar, put that experience also plays a modest role in patch choice at this stage. (C) 2000 The Association for the Study of Animal Beh aviour.