The potato stem borer was first reported as an economic pest in the United States in 1975. A native of Europe, Siberia, and Japan, it was accidentally introduced into the maritime provinces of Canada before 1908. The insect has spread slowly westward and southward, being reported a pest in western Quebec in 1958 and in eastern Ontario in 1968. Infestations found in the northeastern United States are apparently the result of moths flying southward from Quebec and Ontario. The insect attacks a number of crops including corn, potatoes, tomatoes, rhubarb, pumpkins, beets, and peas. It also feeds on such weeds as quackgrass, green foxtail, barnyard grass, and dock. It overwinters in the egg stage and there is one generation a year.