Silk Web Production
Embiopterans produce a silk thread highly similar to that produced by the much better known silkworm Bombyx mori. The silk is produced in spherical secretary glands in the tarsi of the embiids enlarged forelimbs, and can be produced by both adults and larvae. Unlike Bombyx mori and other silk-producing (and spinning) members of both Lepidoptera and Hymenoptera, which only have one pair of silk glands per individual, some species of embiid are estimated to have up to 300 silk glands: 150 in each forelimb (Engel & Grimaldi 2006). These glands are linked to 'setae-like cuticular process called a silk ejector' (Alberti & Storch 1976), and their exceedingly high numbers allow individuals to spin large amounts of silk very quickly, creating extensive galleries (see image below). The silk web is produced throughout all stages of the embiopteran lifespan (Collin et al. 2008), and requires very little energy output (Edgerly et al. 2006).