Bitterroot Restoration

Class: Insecta
Order: Lepidoptera
Family: Sesiidae
Genus: Paranthrene

Poplar Borer (Paranthrene dollii) is a moth which attacks poplar species (mainly black cottonwood, balsam poplar, and hybrid poplars). Trembling aspen and paper birch are rarely attacked.

Larvae are C-shaped, legless grubs. Their body is creamy-white with a brown head. They are about 1.3 cm long when mature. Adults are stout weevils with long curved snouts, and are 0.8 to 1.0 cm long. Their body is predominantly black, and their back is densely covered with tiny black and either grey or pink scales, which form an irregular band.

Causes:

• Upper crown or whole tree broken over or dead
• Irregular splits and holes in the bark, through which red-brown and white shavings exude
• Piles of shavings around the base of the stems