If damage occurs in a centrally located petiole the plant must often be discarded. Some pupae may be affected by discing as well. Among the most common parasites are the wasps, Hyposoter exiguae and Chelonus insularis, and the tachnid fly, Lespesia archippivora. Viral diseases also kill significant numbers. Weeds can be pulled and readily examined whereas celery is often brittle and easily damaged during the early morning and late evening hours when larvae are active.
Populations can build rapidly, so check fields twice a week.
Monitor adults with pheromone traps placed along the edges of fields. This is a particularly good technique for detecting large emergences or migrations occurring on weather fronts. Reliable treatment levels have not been established, but the presence of more than one large larva or five small larvae on 25 plants would be of concern. Apply as a foliar spray. Use allowed under a supplemental label.