Synonyms and other taxonomic changes
described in 1896 by Hulst, who originally placed it in genus Hydriomena
Explanation of Names
costiguttata: from "costa" (a rib) + "guttate" (spotted, as with drops); refers to the large dark spots along the forewing costa (the anterior marginal "rib" of an insect's wing)
Size
wingspan about 22-27 mm, based on five Internet photos
Identification
Adult: forewing pale gray, speckled, and with darker shading beyond subterminal line; basal, AM, median, and PM lines double, dark, fine; 3 large black patches along costa represent upper end of basal, median, and PM lines; subterminal line pale, zigzag; small dark discal dot (sometimes absent) just outside median line; hindwing paler, with fewer markings but more prominent discal spot (if present); terminal line a series of paired dots on all wings
Range
California to British Columbia, east to Arizona, Utah, and probably Colorado
Season
adults fly from May to September in California
See Also
related species lack the large black patches along the forewing costa
Internet References
pinned adult images (Bruce Walsh, Moths of Southeastern Arizona)
pinned adult image and collection site map (All-Leps)
larval foodplant mentioned under the account of a related species (Jeff Miller, Macromoths of Northwest Forests and Woodlands, USGS)
presence in California; list of 14 specimen records with dates and locations (U. of California at Berkeley)
presence in Utah; list (Joel Johnson, Utah Lepidopterists Society)
distribution in Canada British Columbia only (CBIF)
Contributed by
Robin McLeod on 24 February, 2008 - 5:01pm
Additional contributions by
Steve MorrisLast updated 17 December, 2022 - 9:12am