About Spodoptera praefica Grote, 1875
Spodoptera praefica, commonly known as the western yellow-striped armyworm, is a moth species belonging to the family Noctuidae. Its current known distribution ranges from British Columbia to California on the Pacific coast of North America, extending east to Utah and north to Alberta. As of 4 October 2021, this species is not present in the area covered by the European and Mediterranean Plant Protection Organization (EPPO), but it is classified as a high risk for invasion into this region. The wingspan of adult moths measures 35 to 40 millimetres, which equals 1+3⁄8 to 1+9⁄16 inches. This species is similar in appearance to Spodoptera ornithogalli, but the forewings of S. praefica are paler and do not have the blurry white stripe seen on S. ornithogalli. The hindwings of S. praefica are white or gray, with a small brown dot on the ventral side. Adult western yellow-striped armyworms are active in flight during two periods each year: from March to April, and again from August to September. The larvae are black with yellow stripes, and have an inverted "y" shaped marking on the head. Larvae feed on the leaves of a wide range of herbaceous plants, including common agricultural crops such as alfalfa, potato, rice, sugar beet, and sweet potato.
