Synonyms and other taxonomic changes
Euxoa pleuriticoides Benjamin, 1936
Identification
Adult: forewing grayish-brown with black double basal, AM and PM lines, usually indistinct; ground color of wing slightly paler in basal half; orbicular spot circular, with prominent pale perimeter and dark interior; reniform spot with smudged blackish lower half and pale perimeter; claviform spot black-edged, usually discernible; black diffuse median line zigzags from lower corner of reniform spot to inner margin, almost touching PM line; subterminal line pale, faint, with several blackish wedges distributed along proximal edge; terminal line scalloped or zigzagged; hindwing dirty white basally, shading to gray distally, with dark veins and discal lunule; fringe pale with some dark scaling at ends of veins; collar, tegulae ("shoulder pads"), and top of thorax all uniformly grayish-brown
Range
northern California to Colorado, north to southern British Columbia and Alberta
Habitat
montane grasslands and arid "high plains" grasslands; adults are nocturnal and come to light
Season
adults fly from July to September in California; June and July in Alberta
See Also
Euxoa occidentalis forewing has smaller and paler orbicular spot, no discernible claviform spot, no black smudge in lower half of reniform spot, its median line almost touches AM (not PM) line at inner margin, and its hindwing is more uniformly dark (
compare images of both species at CBIF)
Euxoa pestula forewing and hindwing almost uniformly colored, showing little contrast;
E. pleuritica collar and tegulae are pale-edged and dark, contrasting against lighter brown on top of thorax (
compare images of all 3 species at CBIF);
pleuritica is also more eastern, not appearing on lists from
California,
Colorado, or
Oregon, and probably doesn't occur in western British Columbia
Eurois nigra forewing is more uniformly dark with obscure markings, reniform spot is almost invisible, claviform spot is not present, and hindwing is paler distally instead of darker distally (
compare images of both species at CBIF)
Internet References
pinned adult image by G.G. Anweiler, plus habitat, flight season, description, distribution (Strickland Entomological Museum, U. of Alberta)
presence in Colorado; list (Paul Opler, Moths of Rocky Mountain National Park, USGS)
presence in Oregon; list citing 11 specimens in collection, including locally-collected specimens (Oregon State U.)
presence in California; list of 8 specimen records with dates and locations (U. of California at Berkeley)
distribution in Canada; list of provinces of occurrence (U. of Alberta, using CBIF data)