Hyphantria cunea

Fall webworm

Description

The adult fall webworm moth is bright white, with a hairy body. It builds impressive silk tents that sometimes enclose entire branches. Initially, the larvae skeletonize the leaves, and as they continue to feed, only the thicker veins remain intact. The larvae live gregariously at first, and then become solitary as they grow. Small larvae grow quickly and they spin whole twigs and branches into web-like fibres. They can grow up to 30-45 mm in length, and adult larvae have a darker stripe on their backs. The larvae frequently pupate together in bark cracks, and the pupae overwinter. The first generation of the moth swarms from April until May, while the second generation is active from August to September. The eggs are laid on leaves. This pest originally spread into Europe from the USA relatively recently, starting in the 1940s. The frequency of its occurrence has been increasing lately.

Symptom

Leaves are skeletonized at first, later they are damaged so that only thicker veins remain intact. The leaves are damaged by the larvae which live at first gregariously and later singly.

Tree Species: Elderberry, Pear, Apple Tree, Maple, Mulberry, Walnut, Poplar

Part of a plant- attacked: Leaf / Needle

Pest significance: Harmful

Pest Category: Insects

Invasive Species: Yes

Present in EU: Yes

Seasonal frequency of occurrence