Larger larvae are usually found deep in the whorl often below a 'plug' of yellowish brown frass. Larger fall armyworm larvae consume large amounts of leaf tissue resulting in a ragged appearance to the leaves similar to grasshopper damage.

The most common damage is to late pretassel corn. Unlike armyworm, fall armyworm feeds during the day and night, but are usually most active in the morning or late afternoon. Therefore it is important to find the live larvae and determine which insect is causing the damage. Although initial symptoms of damage are similar, thresholds and control measures differ. Small holes and 'window pane' feeding in the leaves emerging from the whorl are common. Very early symptoms of fall armyworm resemble European corn borer infestation. Fall armyworm moths can be very numerous in late summer. Fall armyworm has four dark spots arranged in a square on top of the eighth abdominal segment.įigure 2. The corn earworm has an orange-brown head, while the armyworm has a brown head with dark honeycombed markings. Fall armyworm resembles both armyworm and corn earworm, but fall armyworm has a white inverted 'Y' mark on the front of the dark head. Larvae have four pairs of fleshy abdominal prolegs in addition to the pair at the end of the body.

There is a wider dark stripe and a wavy yellow-red blotched stripe on each side. Fall armyworm has a dark head capsule with a light inverted 'Y' marking.įall armyworm larva vary from light tan to black with three light yellow stripes down the back. Larvae hatch in 3 to 5 days and move to the whorl.įigure 1.

Egg masses are covered with a coating of moth scales or fine bristles. The spherical gray eggs are laid in clusters 50 to 150, usually on the leaves. Early detection and proper timing of an insecticide application are critical.Įach summer, adult moths move northward in progressive stages from overwinter sites along the gulf coast region and begin to appear in Kentucky in late June or early July. Like European corn borer, fall armyworm can only be effectively controlled while the larvae are small. While fall armyworms can damage corn plants in nearly all stages of development, it will concentrate on later plantings that have not yet silked. Fall armyworm causes serious leaf feeding damage as well as direct injury to the ear. Late planted fields and later maturing hybrids are more likely to become infested. University of Kentucky College of Agricultureįall armyworm can be one of the more difficult insect pests to control in field corn. ENTFACT-110: Fall Armyworm in Corn | Download PDF by Ric Bessin, Extension Entomologist

Download army worm moths