Grasshoppers comprise many species. They are not considered major pests in potato fields but when seasonal conditions are favorable, they may migrate into potato and can defoliate sections of a field.
Description
Grasshoppers have large, strong, biting jaws. Their hind legs are strong and adapted to jumping. Their body is elongated and slightly cylindrical. It is partially sheathed by long, slender membranous wings topped with outer leathery wings. Their antenae are relatively short. There are five species that are responsible for most of the damage in North America: migratory, differential, two-striped, red-legged, and clear-winged grasshoppers.
From left: Grasshopper defoliation, more grasshopper defoliation, grasshopper leaf holes
Damage
Grasshoppers are migratory, able to move across a large distance. Their damage in potato is most severe in the central region of the continent, the Plains States and in the mountainous areas of the West. Their greatest damage is by chewing holes in foliage. Damage usually occurs for a short time toward the end of the growing season and there is only one life cycle per year. The outbreaks need to be very severe to cause economic damage in a field but damage can be severe enough along the field edge to cause yield reduction.
Management
Young grasshoppers are controlled by soil-applied systemic insecticides used for other pests. Mid and late season treatment can be limited to the edges of field where grasshoppers are seen. Treatment is seldom required.