an insect of the family Yponomeutidae (ermine moths), order Lepidoptera. A dangerous pest of apple trees, the insect is distributed in all apple-growing zones. The wing span is 18–22 mm; the anterior wings are silvery white with three rows of black dots; the posterior wings are ash gray. The young caterpillars, after wintering on branches under a scutellum, at first feed inside young leaves, chew out their pulp, and gnaw through to the exterior, enmeshing them in gossamer. The tree is weakened and sheds its fruit.
Control measures consist in spraying the apple trees with insecticides before the buds open or immediately after flowering.