Species Drasteria adumbrata - Shadowy Arches - Hodges#8636

8636

Drasteria adumbrata (Behr, 1870)

Synedoida adumbrata

Syneda adumbrata

Phylogenetic sequence # 930910 (1)

ADUMBRATA: from the Latin "ad" (to, toward, nearness to) + "umbra" (shade, shadow); probably refers to the dark forewing, and is the origin of the common name Shadowy Arches

Wingspan about 32 mm.

Adult: forewing mottled light and dark brown; basal area, median band, reniform spot, and subterminal area paler; AM line curves toward base near inner margin; hindwing creamy yellow to orange with black marginal and PM bands, the latter joined to black discal crescent.

coast to coast in southern Canada, south in the west to California and Colorado, south in the east to New England and Michigan

dry montane woodlands and sandy open woods; a rapid-flying, day-active species; subspecies saxea regularly comes to light in southern BC, whereas subspecies alleni is very rarely attracted to light [Handfield 1999]

adults fly in summer

larvae feed on Lowbush Blueberry (Vaccinium angustifolium) in Quebec [Handfield 1999] and probably other Vaccinium species in the west; also recorded on Bearberry (Arctostaphylos uva-ursi)

subspecies D. a. saxea has a slower flight and is easier to approach than the extremely wary alleni; flushed individuals often fly a short distance before alighting on the ground

Northern Arches (Drasteria hudsonica) forewing usually gray rather than brown, and hindwing tends to be more pale cream rather than orange, but there is considerable overlap among individuals and subspecies, so these are only generalities; a more reliable feature is the AM line, which continues on an outward slant near the inner margin in hudsonica, but curves basally near the inner margin in adumbrata (compare images of both species at CBIF)

Moth Photographers Group (2)

pinned adult image (CBIF)

The Barcode of Life Data Systems (BOLD) (3)

University of Alberta E.H. Strickland Entomological Museum (4)

distribution in Canada list of provinces (U. of Alberta, using CBIF data)

classification giving Synedoida and Syneda as junior synonyms of Drasteria (Brian Pitkin, Butterflies and Moths of the World)