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Upcoming Events

Photos of insects and people from the 2022 BugGuide gathering in New Mexico, July 20-24

National Moth Week was July 23-31, 2022! See moth submissions.

Photos of insects and people from the Spring 2021 gathering in Louisiana, April 28-May 2

Photos of insects and people from the 2019 gathering in Louisiana, July 25-27

Photos of insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Previous events


Species Spodoptera praefica - Western Yellowstriped Armyworm - Hodges#9667

Spodoptera ornithogalli ? - Spodoptera praefica Unknowm Moth - Spodoptera praefica Unknown Moth - Spodoptera praefica Yarrow-munching caterpillar - Spodoptera praefica Western Yellowstriped Armyworm Moth - Spodoptera praefica noctuid (Xestia c-nigrum?) - Spodoptera praefica Noctuidae: Spodoptera praefica - Spodoptera praefica black cat - Spodoptera praefica
Show images of: caterpillars · adults · both
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Noctuoidea (Owlet Moths and kin)
Family Noctuidae (Owlet Moths)
Subfamily Noctuinae (Cutworm or Dart Moths)
Tribe Prodeniini
Genus Spodoptera (Armyworms)
Species praefica (Western Yellowstriped Armyworm - Hodges#9667)
Hodges Number
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
Life Cycle
two generations per year; overwinters as a pupa in the soil
See Also
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)
Internet References
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)
pinned adult image and photos of related species by Jim Vargo (Moth Photographers Group)
images of Cotesia marginiventris a braconid wasp parasitoid of noctuid larvae, including Spodoptera praefica (Michael Sharkey, U. of Kentucky) - young larva image
presence in Utah; list (Joel Johnson, Utah Lepidopterists Society)
presence in California; list (U. of California at Berkeley)
distribution in Canada list of provinces (U. of Alberta, using CBIF data)