The effect of previous foraging success on web-building behaviour in the sheet-web spider, frontinellina cf. frutetorum (Araneae Linyphiidae)

We examined the influence of previous foraging success on foraging effort in the sheet web spider Frontinellina cf. frutetorum (Linyphiidae). Foraging effort was estimated via the spider's investment in web construction as indicated by web size. We manipulated previous foraging success by providing spiders with supplementary prey items for 2 days and subsequently removed the webs. Fed spiders were in a better condition than control spiders. However, in contrast to previous studies, supplemented spiders did not reduce their foraging effort. On the contrary, control spiders built smaller webs after web removal, while fed spiders did not reduce the size of their webs. Moreover, we found a positive relationship between spider body condition and web size. We suggest that high energetic demands of web construction as well as web longevity in sheet weavers results in a web-management strategy in which further investment in web size is a positive function of foraging success.