University of Alberta Museums Search

A medium-sized (4.0-5.0 cm wingspan) grey and white dagger-moth. The lines, except for the postmedian line, are obsolete and indicated only by dark blotches where they would meet the costa. The postmedian line is incomplete and marked by a series of darker spots or small crescents, with the 'dagger-mark" in the anal area prominent and enlarged. The area beyond the postmedian line is usually darker grey than the rest of the forewing, and there is a terminal line made up of black spots between the veins. The orbicular spot is a faint thin black oval, and the reniform is indicated by only a few dark scales. There is a thin but prominent black basal dash. The hind wing is white, with a series of black dots marking the terminal line. The females are larger and somewhat darker, especially on the hindwings. Antennae simple. The Cottonwood Dagger Moth can be separated from the similar Fingered Dagger Moth (A. dactylina) by the black basal dash (absent in dactylina), and the crisper dark markings (smudged in dacylina). A. vulpina is also similar, but is larger, has broad chalky grey-white wings and a short, thick basal dash. Alberta specimens have been treated by Bowman (1951) as subspecies lepusculina, felina, and canadensis.

No Alberta data; elsewhere in Canada recorded hosts include mainly poplars (Populus spp., including P. tremuloides, P. balsamifera, P. nigra, P. grandidentata, P. trichocarpa and P. acuminata) and occasionally willows (Salix sp.) and Paper birch (Betula papyrifera)(Prentice 1962).