|scientific name Spodoptera praefica |
common name Western Yellowstriped Armyworm
In Alberta it has been found only in the dry grasslands region in the Milk River valley at Writing-on-stone Provincial Park.
A medium size moth (ws= cm) with medium brown forewings marked with both lighter yellow brown and darker brown. The normal lines and spots are partially outlined with fine pale lines. The area along the cubital vein between the orbicular and reniform is white, and the orbicular is frequently outlined and partially filled with pale scales as well. There is a series of short black streaks between the veins in the subterminal area, and thin white subterminal and terminal lines. Fringe dark brown streaked with white at the veins. The hindwings of males are dirty white with dark scales along the veins, a thin dark incomplete terminal line, and a light fringe. Sexes similar but females with darker hindwings. The forewing pattern is rather difficult to describe, but quite distinctive.
In Alberta, probably not a permanent resident, with adults migrating in from further south in late summer. Adults are nocturnal and come to light. The caterpillars are general feeders on a wide variety of broad-leaved plants, including a number of agricultural crops such as potatoes and sugar beets.
The caterpillars are general feeders on a wide variety of broad-leaved plants, including a number of agricultural crops such as potatoes and sugar beets. The larvae are reported to feed during the day.
A southwestern species, ranging from extreme southern Alberta and southeastern BC south and west to at least California.
The Western Yellowstriped Armyworm barely reaches Canada from the southwest, and is a rare moth in extreme southern Alberta. Further south it is a serious agricultural pest on a variety of crops.
Comments are published according to our submission guidelines. The EH Strickland Entomological Museum does not necessarily endorse the views expressed.