University of Alberta Museums Search

A medium-size (3.4-4.1 cm wingspan) grey-brown hepialid moth. Forewings are mottled light and dark grey-brown, with the lighter area forming a poorly defined stripe which angles from the wing base to the lower margin, then obliquely to the wing tip. The median area above this band is darker brown, as are a series of spots or blotches along the costa. The terminal area is also darker brown. Hindwings are dull grey-brown, unmarked. The fringes on all wings are checkered. Antennae in both sexes are reduced and hair-like. The reduced, hair-like antennae will identify gracilis as a Hepialid moth, and the dull brown mottled appearance will separate it from the other small Alberta hepialids, which have pink or reddish-brown forewings with silvery-white markings.

No Alberta data. In some areas of eastern North America, it is a significant pest on the roots of Balsam fir (Abies balsamea) and Red spruce (Picea rubens). They are also reported to feed on the roots of many other plants, including White spruce (Picea glauca), birches (Betula sp.), Aspen (Populus tremuloides), and ferns (Dryopteris sp. and Athyrium filix-femina).

From Newfoundland and Labrador, south in the Appalachians to at least the Carolinas, and west across the southern Boreal Forest region of Canada to central Alberta. Rare in Alberta, where it has been collected along the southern edge of the Boreal forest, in the Lac la Biche and Edmonton areas.