Missouri Pest Monitoring Network
Corn Earworm I.D.

Identification of moth
(stage attracted to and captured in traps)

• Moths are buff-colored with irregular wing markings and a wingspan of 1 ½ inches.

Identification of larvae (damaging stage)

• Small larvae are cream-colored but larger ones have variable coloration (pale green to rose to brown) and pale lateral stripes.
• Unlike other striped larvae with four abdominal prolegs, corn earworm larvae have numerous small, black spines along their back and sides.
• The larval stage of the corn earworm and the tobacco budworm, Heliothis virescens (F.), look very similar; however, corn earworm larvae lack an extra tooth on the inside of their mandibles. A 10x hand lens is necessary to distinguish both the black spines on the corn earworm larvae and the presence or absence of the extra mandible tooth.
• Once a larva is full-grown, it crawls down the host plant and pupates in the soil. The next generation of moths emerges within the next 10 to 25 days.

Identification of Eggs

• Eggs are ribbed, white to cream-colored and dome-shaped. They are laid near the terminals and fruit of its host plants. Reddish brown bands appear on the eggs before the larvae hatch.