Imported Willow Leaf Beetle

family: chrysomelidae
species: plagiodera versicolora
common names: imported willow leaf beetle
hosts: willows
notes:

Agriculture and Agri-Food Canada Insect Identification Sheet No. 96 1986

Imported Willow Leaf Beetle

Plagiodera versicolora (Laicharting)

The imported willow leaf beetle is one of four fairly common species of willow leaf beetles found in Canada.

Injury:

Both the adult and larva feed on the foliage of willow and poplar trees, leaving only the midrib and a network of veins. By late June, parts of heavily infested trees may appear brown, as if scorched.

Life Cycle, Appearance and Habits:

The small, metallic-blue adults overwinter in leaf litter or sheltered places, such as crevices in the tree's bark. They emerge in May and start feeding on developing leaves. The females lay small irregular masses of yellow, oval eggs on the undersides of the leaves; these hatch into black, slug-like larvae that can skeletonize the leaves from both surfaces. When full-grown, the larvae pupate, usually on the leaves' underside. There may be two or three generations a year.

Control:

Although this pest seldom kills trees, ornamental trees or shrubs are somearial seriously affected. Consult your provincial agricultural representative for control measures if the infestation appears heavy.