Explanation of Names
ALBOSIGMA: from the Latin "albus" (white) + the Greek alphabet character, sigma, which is S-shaped; refers to the curved white marking on the forewing
rare in southeastern United States; common elsewhere in range
Adult: forewing light grayish to smoky brown, deeper brown or reddish-brown patch near apex; PM line forms a prominent white S shape just below costa; two parallel whitish lines cross the wing in the basal and AM areas
[adapted from description by Charles Covell and Lynn Scott]
Larva: coloration variable, ground color dark with broad yellow to orange stripes and abundant downy, pale hair; head dark brown, vertex often with paler chestnut spot; dorsum with 4 yellow to orange stripes, vague in some individuals; medial black wart on first abdominal segment nearly twice size of wart on eighth segment
[description by David Wagner and Valerie Giles]
Found coast to coast in United States and southern Canada, north to Great Slave Lake, Northwest Territories. Scarce south of New Jersey, Kentucky, Missouri.
deciduous woodlands and shrublands
Adults fly from late March or April to September (May to August in the north)
larvae from June to September.
Larvae feed on poplar and willow, aspen, sometimes willow. Construct large communal tents in their host trees.
Spring specimens which are paler and marked by a series of pale lines have been named form "specifica"; summer specimens are darker and more uniform in color and pattern.
Adults are nocturnal and come to light, but are not attracted to sugar baits.
distinguished from Clostera apicalis (Apical Prominent) by the two parallel whitish lines crossing the forewing
distinguished from all other Clostera species by the sharp demarcation of the dark apical patch on the forewing
Covell, p. 328, plate 42 #11 (1)
Wagner, p. 280, photos of larva, adult (2)
plus common name reference and food plants (Larry Line, Maryland)
pinned adult image
of male, plus habitat, seasonality, description, biology, food plants, distribution (G.G. Anweiler, U. of Alberta)