The army cutworm begins laying eggs in late August and cancontinue through October. Up to 3,000 eggs are deposited per female on or just beneath the soil surface. Eggs hatch in the fall following rain or snow. This cutworm species overwinters in the larval stage. Larvae become active in late winter or early spring and are particularly damaging to winter wheat.
Army cutworms feed above ground so evidence of feeding damage indicates their presence.
However, they feed during night, from dusk to dawn, staying below ground during the day except on very overcast days when they can be found feeding above ground. When larvae are abundant and food supply is short, the larvae will move en masse to adjacent fields, hence the name army cutworm. Adult moths, also known as millers, emerge from these cells in May and early June. An interesting phenomenon with this cutworm species is its seasonal migration to high elevations in the Rocky Mountains. Adult moths are active at night at these higher elevations, feeding on alpine flower nectar.