Birch and alder flea weevil

Distribution

Eastern Canada

These small native snout beetles are found in eastern Canada and in widely scattered areas of the United States.

Damage, symptoms and biology

The beetles feed on the leaves making circular holes in them and the larvae make small irregular blotch mines in them. Heavy infestations cause the leaves to turn brown and, as early as early August, give hedges and trees the appearance of having been scorched by fire. Twigs are sometimes killed as a result of overfeeding.

The adults are tiny black beetles about 2 mm long. They hibernate during the winter beneath loose bark on the trees, under debris on the ground near the trees, or in the soil. They emerge from hibernation in early June when the buds are bursting, and feed, first on the developing buds, and later on the underside of the leaves. The females lay their eggs on the underside of the leaves during July. The eggs hatch in 12 to 15 days and the young larvae immediately begin mining the leaves. The larvae are fully grown in about 5 weeks, then they pupate in the mines in the leaves. The beetles emerge in August and feed on the leaves until they go into hibernation.