Fall armyworm

	Fall armyworm

Corn is vulnerable to fall armyworm (FAW) invasions from emergence until it’s waist high. Two or three generations can hatch per season. Early generations feed on young leaves and can destroy entire plants. Later generations damage leaves above and below the ears. The longer the worms go untreated, the harder they become to treat because they feed deeper into the whorl. In fact, control of FAW with traditional pesticides is difficult and often not economical.

Fall armyworm geography map

	Fall armyworm damage

Damage

Early signs of feeding will closely resemble that of European corn borer. Window-pane feeding on leaves is very common for small larvae as they leave the whorl. Large larvae feeding in the whorl are often covered with a plug of frass. This provides a protected area from which they can feed.

Plants that only have whorl damage often recover without yield reduction. However, due to their aggregating nature, extensive damage can occur if plants are left untreated. Larval feeding on the leaves often results in the plant appearing ragged. Larvae also will feed on ears when they are present, often resulting in partial or complete ear destruction.