Northern Prairie Wildlife Research Center
Wingspan 5.3 cm. Forewing is pale gray with reniform and orbicular discal spots strongly outlined. This noctuid is abundant and widely distributed in western North America. Moths fly in midsummer. Caterpillars feed on the foliage of alder (Alnus).
Similar species: the other species of Acronicta are smaller in size; Acronicta lepusculina forewing with thin black basal and subanal dashes, widely distributed in riparian forests, caterpillars feed on poplar (Populus) and willow (Salix); Acronicta vulpina forewing with discal spots reduced to small black dots and with a black basal dash, uncommon; Acronicta innotata forewing with discal spots reduced to small black dots but lacking a black basal dash, uncommon; Acronicta cyanescens forewing is gray with a black basal dash, uncommon, caterpillars feed on foliage of snowbrush (Ceanothus velutinus).