Webs: Diversity, Structure and Function

Abstract

Web building has been such a highly successful foraging innovation among spiders that the vast majority of extant spiders are web builders. The structure of spider webs varies substantially between species, and web building has even been lost completely in some clades. Examples of different web forms include the classic orb webs, which may be orientated vertical to the ground or horizontal, sheet webs, and cobwebs, which consist of three-dimensional meshwork and ascending sticky threads for support and capture of prey. The architecture of webs may also vary within clades and even within species. This may be a consequence of: (i) individuals adapting their web structures to the environment; e.g., larger webs are built in areas where more space is available, (ii) spiders varying their webs to tune its performance, e.g., when spiders are exposed to different prey, or (iii) silk expression constraints, e.g., when on diets lacking certain nutrients. We review the literature, focusing on contributions from the Neotropical region, showing that spider webs vary in structure and function at multiple levels and so must be considered a dynamic, variable, extended phenotype of its builder. Webs accordingly depict the foraging, mating, and defensive strategies, and physiological status, of the spider.