Species Spodoptera praefica - Western Yellow-striped Armyworm Moth - Hodges#9667

9667

Western Yellowstriped Armyworm (larva)

wingspan 35-40 mm

larva length to 40 mm

Adult: forewing variably grayish-brown to yellowish-brown with pale scaling along veins; oblique yellowish shade line extends across orbicular spot toward PM line; basal, AM, PM, and ST lines irregular, pale yellow or white; hindwing pale gray with dark veins and discal lunule, thin dark terminal line, and white fringe

Larva: head black with inverted white Y shape on front; body black with prominent white or yellow dorsolateral line; 3 stripes along each side - a gray one near the top, a black one below that, and a reddish-brown one below that

British Columbia to California, east to Utah, north to Alberta

adults fly in March and April, and again in August and September

larvae present from May to July, and again in the fall before pupating

larvae feed on leaves of crops such as alfalfa, potato, rice, sugarbeet, and sweet potato, plus various other herbaceous plants

two generations per year; overwinters as a pupa in the soil

Yellow-striped Armyworm (S. ornithogalli) forewing is usually grayer and shows more contrast between pale and dark areas; it is a mostly eastern species - the ranges of both species overlap only in California (compare images of both species at CBIF and MPG)

Moth Photographers Group (MPG)

Pacific Northwest Moths

Barcode of Life (BOLD)

live larva and adult images by Ralph Berry, plus overview of biology (Oregon State U.)

pinned adult image (G.G. Anweiler, U. of Alberta)

pinned adult image (California Dept. of Food and Agriculture)

images of Cotesia marginiventris a braconid wasp parasitoid of noctuid larvae, including Spodoptera praefica (Michael Sharkey, U. of Kentucky)

flickr.com - young larva image

presence in Utah; list (Joel Johnson, Utah Lepidopterists Society)

presence in California; list (U. of California at Berkeley)