University of Alberta Museums Search

A medium-size moth (3.0-4.0 cm wingspan) with grey forewings and white hindwings. Forewings are a clear even bluish-grey. Basal and antemedian lines are doubled and incomplete, and the postmedian line is a thin, dark complete line. There is a thick, black basal dash and a short thick dash in the anal angle. The area between the orbicular and reniform spots is also filled with black scales in an X or square shape, hence the name. Overall appearance is clean and rather elegant. Hindwings are shining white, with some darkening along the margin. The antennae are simple, and the sexes are similar, except the female is somewhat darker, especially on the hindwings. See also Acronicta radcliffei, A. grisea, A. interrupta and A. furcifera, all of which are either darker grey or with more extensive dark patterning.

No Alberta data; elsewhere in Canada recorded larval hosts include Pin cherry (Prunus pennsylvanica), Chokecherry (Prunus virginiana), plum (Prunus sp.), Saskatoon (Amelanchier sp.), Trembling aspen (Populus tremuloides) and willow (Salix). The principal host appears to be species of wild cherries (Prunus).

In Canada, it occurs sparingly across the wooded area north to the southern edge of the Boreal forest. From western Quebec, west to the Rocky mountains in Alberta and north western British Columbia. In Alberta, it has been collected from Calgary, north along the Red Deer River to the Redwater dunes in the southern boreal forest, just northeast of Edmonton. It has also been collected in the Peace River district of British Columbia, just west of the Alberta border. Widespread in the western USA.