Pest Profile

Beet Armyworm
Spodoptera exigua
  • Beet armyworm caterpillar: variable color from green to black with a yellow running stripe on either side.
  • Beet armyworm moth: small brownish moth with lighter spots, up to an 1" in length.

Pest Description

Beet armyworm larvae can vary from light green to nearly black. They have four pairs of abdominal prolegs and a dark head capsule. Many fine, white wavy lines run along the back, and a broader stripe occurs along each side. There is usually a distinctive dark spot on each side, just above the second pair of true legs. Females lay eggs in masses, covering them with hairs and scales. Eggs hatch in a few days and larvae feed for about three weeks, sometimes spinning slight webs over the foliage.

Source of information

J.P. Michaud, KSU Entomology

Pest photo source

Phil Sloderbeck, KSU Entomology