Co-adapted foraging traits in a guild of orb-weaving spiders.

From a previous two-species comparison, specific suites of morphological and web design traits are predicted to characterize foraging specializations in old-field orb-weaving spiders. Species with stout legs, large fangs, open mesh webs, high webs, and retreats should specialize on innocuous, rapidly escaping prey types. Species with long legs, small fangs, dense mesh webs, and low webs that rest in the hub should specialize on dangerous, clumsy prey that escape from webs slowly. Factor and discriminant analyses are used to test for these association patterns in eight co-occurring species of old-field orb-weavers. The association between most of the characters is supported, but the appearance of a new combination suggests that another dimension needs to be added to the model. Habitat use and diet predicted by the model are tested for species where data are available.