Silk: Biology, Structure, Properties, and Genetics

General Biology Silks are produced by the more than 30,000 known species of spider [1], and by most of the 113,000 species in the insect order Lepidoptera [2]. In addition, silks are produced by members of several other insect orders [3]. For every silk that has been characterized in any detail, over 1000 uncharacterized silks are known to exist This book describes only a very small number of spider, silkworm and aquatic midge larva silks. The reader will discover (or be reminded) that silks are truly remarkable materials in many respects. On statistical grounds alone, it is highly unlikely that the silks characterized to date have shown us the limits of what Nature can achieve in regard to the mechanical properties of fibroin proteins. Concern about the extinction of (especially uncharacterized) species therefore must be maintained far beyond the agenda of specialized ecology: materials technology also stands to lose when