|scientific name Coenophila opacifrons |
common name Blueberry Dart
In Alberta widespread but local in the boreal forest and foothills regions; rare in the northern Aspen parklands.
A medium-size (approx. 3.2-3.8 cm wingspan) purple-grey moth with reddish wine-red shading and tints on the forewings. Costa lighter grey, especially along the basal half. The orbicular and reniform are joined on their lower edge by a dark rusty or black line, which frequently also fills the space between the two spots. However, the extent and intensity of the dark shading around the orbicular is highly variable, and in many specimens is almost obsolete. Hindwings fuscous, shading darker on the outer half except for the paler fringe, and with a dark discal mark. Sexes similar except male antennae bipectinate, female simple. Very similar in appearance to some species of Xestia, but genitalia of both sexes very different. Adults and genitalia of both sexes are illustrated by Lafontaine (1998). The mature larva is about 3.5 cm long, pale grey to blackish with a dark brown reticulate pattern and submedian arcs. It is described in detail and illustrated in color by Lafontaine (1998: Pl.8 (21).
Adults are nocturnal and come readily to light. There is a single annual brood, with adults usually in the latter half of July and early August, occasional specimens earlier and later. No Alberta larval hostplant data; elsewhere Leatherleaf (Cassandra calyculata), blueberry (Vaccinium spp.) and Sweet gale (Myrica gale). Leatherleaf is reported to be the preferred host (Hensel, in Lafontaine, 1998).
Labrador and Newfoundland, south to New Jersey; west across the Boreal forest to eastern British Columbia, south in the mountains to southern Montana. In addition to the localities plotted on the map, Bowman (1951) states it has also been collected in “Zone 15” (Peace River region).
Although opacifrons is usually associated with peat bogs and fens, specimens occasionally turn up in other habitats, including a female that showed up in a blacklight trap in my backyard in Edmonton and a specimen that Charley Bird collected in the Buffalo Lake Conservation Area near Stettler. Until quite recently, opacifrons appeared in the literature as a subspecies of Palaearctic C. subrosea. To further confuse matters, it has appeared in the literature in the genera Semiophora, Graphiphora (Xestia), Anomogyna and Eugraphe!
The specimen illustrated above is from Wagner Fen, near Edmonton.
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