Observations on Feeding Habits of First-instar Larvae of the Pale Western Cutworm, Agrotis orthogonia Morr. (Lepidoptera: Phalaenidae)

Abstract

The pale western cutworm, Agrotis orthogonia Morr., has been a major pest of cereals in the prairie region of Western Canada since 1911. Present control measures consist of (a) cultural measures that inhibit oviposition in fields being summer-fallowed and (b) starvation of the young larvae by destroying the volunteer plant growth by means of cultivation at a critical period. Cultural operations to minimize oviposition in fields being summer-fallowed have become accepted procedure throughout the area. Control by starvation is practised during outbreak years in fields that have-been “stubbled in” or in those tilled during the moth flight. This procedure has been recommended generally throughout potentially infested areas, but more precise methods of evaluating larval numbers are required so that control may be used only where critical populations are present.