Why do only certain insects escape from a spider's web?

Only heavy insects and those that fly quickly can pass through a spider's web. When an insect is entangled in a web, permanent activity is the best way of getting free. Small wings are conducive to a successful escape, as is a special surface structure of the wings (scales, hairs, lipoid surface). The autotomy of legs, chewing mandibulae or an enzymatic lysis of single threads have nearly no effect. Experiments with approximately 40 taxa of the possible prey of web spiders explain their different behaviour in a spider's web.