Life stages: eggs, larvae, pupae, adult moths.
Female moths lay eggs from August to September on grassy weeds in and around potato fields. These overwintering eggs begin to hatch in late April or early May, and the small larvae bore into the grasses. By late May or early June, the larvae outgrow the stems of the grasses and move on in search of larger weeds or cultivated crops such as potatoes. Larvae usually infest plants in border rows close to grasses where the larvae first fed.
