Spodoptera praefica

Grote, 1875

Western Yellow-striped Armyworm, Western Yellow-striped Armyworm Moth

Spodoptera praefica, the western yellow-striped , is a noctuid native to western North America. The has two periods annually, occurring in early spring and late summer. Larvae are black with yellow stripes and feed on herbaceous plants including several agricultural crops. The species is considered a high risk for invasion into the European and Mediterranean region but is currently absent from that area.

Spodoptera praefica by (c) Ken-ichi Ueda, some rights reserved (CC BY). Used under a CC-BY license.

CATALOGUE-BM-PLATE CXXVIII by Sir GEORGE F. HAMPSON, Bart.. Used under a Public domain license.

Pronunciation

How to pronounce Spodoptera praefica: /spoʊˈdɒptərə priˈfɪkə/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

distinguished from the similar by paler forewings lacking the blurry white stripe, and by hindwings that are white or gray with a small brown dot on the surface. Larvae recognized by the black body with yellow stripes and inverted "Y" marking on the .

Images

Habitat

Associated with herbaceous vegetation in agricultural and natural settings. Larvae feed on leaves of various herbaceous plants.

Distribution

Native to western North America: from British Columbia to California, east to Utah, and north to Alberta. Absent from the EPPO (European and Mediterranean Plant Protection Organization) area as of October 2021.

Seasonality

active March–April and August–September. Two distinct periods annually.

Diet

Larvae feed on leaves of herbaceous plants including agricultural crops: alfalfa, potato, rice, sugar beet, and sweet potato.

Host Associations

alfalfa - larval food plantagricultural crop
potato - larval food plantagricultural crop
rice - larval food plantagricultural crop
sugar beet - larval food plantagricultural crop
sweet potato - larval food plantagricultural crop

Life Cycle

Complete with , larva, pupa, and stages. Larvae are the feeding and damaging stage. Two annually corresponding to the bimodal adult periods.

Behavior

attracted to ultraviolet light sources. Larvae feed externally on foliage.

Ecological Role

Herbivore; larval stage functions as a folivore on herbaceous plants. Potential agricultural pest.

Human Relevance

Agricultural pest of several crops. Considered a high risk for invasion into Europe and the Mediterranean region, with potential to become established as a pest in that area. Subject to monitoring by plant protection organizations.

Similar Taxa

Spodoptera ornithogalliSimilar appearance, but S. ornithogalli has darker forewings with a blurry white stripe and different hindwing pattern.
Spodoptera exiguaBoth are Spodoptera with larval stages that can be pests of agricultural crops, but S. exigua larvae are typically green above and pinkish or yellowish below with a white lateral stripe.

More Details

Invasion Risk

As of 4 October 2021, the is absent from the EPPO area but considered a high risk for invasion there.

Blacklight Attraction

have been documented visiting blacklighting displays in California, indicating activity and attraction to UV light sources.