Comprehensive Description

Caerostris darwini is a newly described orb-weaving spider from Madagascar. It produces the largest orb web known. The silk is extremely tough, tougher than any previously analyzed silk and more than 10 times tougher than Kevlar. (Agnarsson et al. 2010; Kuntner and Agnarsson 2010)

Caerostris spiders (Araneidae) are striking orbweavers known in Africa as "bark spiders". They are widespread throughout the Old World tropics. The large females are highly conspicuous when sitting in the center of their webs, but their name stems from the fact that at least some African species (and possibly some Asian ones) appear to mimic dead bark, twigs, or thorns. Caerostris darwini, however, and some other species in Madagascar, live permanently in the web, which is typically spun over flowing bodies of water. (Kuntner and Agnarsson 2010)