Fall Webworm Moth

(Hyphantria cunea), a moth of the Arctiidae family. The wings, whose spread is 20–35 mm, are snow white and often have dark spots. The larvae measure 25–35 mm; their tops are velvety brown with black wartlike projections and long bristles, and their sides have lemon yellow stripes and orange wartlike projections.

The fall webworm moth penetrated into Europe from North America in 1940 and reached the USSR in 1952 (Transcarpathian Oblast). The moth causes damage to more than 200 species of plants, most often mulberry and fruits. There are two generations per year. The pupae winter under bark, among dry plant remains, and in other places. First-generation moths appear in May; the second generation comes in July-August. The 300–2,500 eggs are laid in clusters in a single layer on the underside of leaves. First-generation caterpillars hatch in the beginning of June and pupate in mid-July; those of the second generation hatch in mid-August and live far into the autumn. Young caterpillars chew on leaves, later consume them entirely, and cover branches and trees with webs. Protective measures against the fall webworm moths include quarantine and treating plants against caterpillars with insecticides or mixes of insecticides with microbiological compounds.