English: The ribbed-cocoon maker (Bucculatrix pomifoliella), a small caterpillar that inhabits apple leaves At A the caterpillar is spinning a mat of silk on the surface of a twig. B shows the silk thread issuing from the spinneret (a) on the under lip of the caterpillar. At C the caterpillar is erecting a line of silk palisades around the site of the cocoon. D and E show the cocoon in the course of construction, built on the silk mat. F is a diagram of the cocoon on under surface of the support, containing the pupa (g) and the shed skin of the caterpillar (h). G shows the interior of the cocoon, its double walls (c, d), and partitions (f) at the front end. H is the finished cocoon surrounded by the palisades