Web-building behaviour in the orb-weaving spider Zygiella x-notata: influence of experience

Zygiella x-notata is an orb-weaving spider that often renews its trap daily . Web building has associated costs and benefits, and building successive w ebs may have consequences for lifetime reproductive success. In the laborat ory, we tested the ability of Z. x-notata to modify its building behaviour in response to various stages in predation (prey detection, capture and ing estion) experienced with a previous web. We determined which stages provide d information for the spiders. Spiders that detected, captured and ingested prey and then rebuilt their web used less silk and made a smaller capture area than in the previous web. There was no effect of prey detection alone on the next web. Capture without feeding gave the same results as capture f ollowed by feeding. The spiders that ate prey without detection and capture (feeding by hand) had the same energetic gains as spiders that caught prey but delayed building a new web. The spiders thus showed plasticity in web- building behaviour and in the amount of silk used (energetic investment) in the short term (from one web to the next). Changes in body condition may t herefore influence web construction. Moreover, information gained during pr ey capture appeared to influence the size and structure of the next web. Th is ability should enable spiders to adapt their web building to maximize th eir fitness. (C) 2000 The Association for the Study of Animal Behaviour.