University of Alberta Museums Search

A small (2.6-3.0 cm wingspan) grey-brown moth with bright yellow hindwings. The forewings are mottled grey-brown except for the area below the stigma between the antemedian and postmedian lines, which is solid dark reddish-black. The stigma is a thin, silver v or u-shape, with a large silver accessory spot distad. The hindwings are bright yellow with a wide black-brown terminal band. The antennae are simple and the sexes are alike. In the boreal forest region of Alberta there are no other Syngrapha species with yellow hindwings. In the mountains and foothills the small size of microgamma will separate it from all yellow-winged Syngrapha species except S. alticola and small specimens of S. ignea, both of which have different shaped stigmas. The very similar S. montana has not yet been recorded from Alberta, but may turn up in the boreal forest region. There are subtle differences between these two species, which are best separated by examining the genitalia, illustrated in the references listed below. Anarta luteola and A. macrostigma are superficially similar and occur in the same habitats, but lack a stigma on the forewings.

No Alberta data. Elsewhere in North America the larvae are known to feed on Labrador tea (Ledum groenlandicum), leatherleaf (Cassandra calyculata) and blueberry (Vaccinium). In Europe it has also been found using willow (Salix).

Holarctic. In Europe, from Fennoscandia and central Europe east to mountains eastern Asia. In North America it is found from central Yukon east across the subarctic to Newfoundland; south to northern New England, Michigan, Wisconsin and west across the Boreal forest to southern British Columbia; south in the mountains to Colorado. In Alberta it has been collected from the southern edge of the Boreal forest to Lake Athabasca, and throughout the foothills and lower elevations in the mountains.