Synonyms and other taxonomic changes
Semiothisa oweni
described in 1907 by Swett, who originally placed it in genus Sciagraphia
Size
wingspan 23-25 mm, based on two Internet images
Identification
Adult: forewing white, heavily speckled with grey; four heavy black blotches along costa. AM and PM lines bold, black, jagged; median line usually broken into several dark spots. The white ground colour gives this species a very contrasting look, unlike the drabber, greyer Macaria species whose markings are otherwise similar. Except for small discal dot, hindwing lacks all black markings; ground colour and speckling similar to forewing.
Range
Newfoundland to west-central Alberta, south in the east to northern New England (McGuffin 1972)
Habitat
boreal bogs and fens containing larch; adults are nocturnal and come to light
Season
adults fly in June and July
Internet References
distribution map plus live and pinned adult images by various photographers, references (Moth Photographers Group)
common name reference [Owen's Larch Granite] plus habitat, flight season, description, larval foodplant, distribution, references (Strickland Entomological Museum, U. of Alberta)
presence in Canada list of provinces of occurrence (CBIF)
