- Adult: Gray and brown moth. Forewings are marked with triangular white spots.
- Larvae: Smooth-skinned caterpillar, ranging in color from light tan or green to black with three light yellow stripes down the back and a white inverted "Y" on the front of its brown head.
- Eggs: Dome-shaped with a flattened surface and a rounded point at the tip. Female covers the egg mass with a layer of gray scales.
Timing of damage: V12 to R6
Type of damage: Primarily feeding on the leaves and whorl but later larvae will move to the tassel and young ears.
Scouting: Check for damage on 20 consecutive plants in five separate locations.
Economic threshold: Treat when eggs are on 5% of plants, or when 25% of plants show damage and live larvae are present. Larger larvae burrow deep into the whorl, where they are protected from insecticide.