Common Names: Armyworm
Scientific Name: Order Lepidoptera, family Noctuidae, many species
Size: Larva - 1-1/2", adult moth - 1-1/2"
Identification: Armyworms are the immature stages of dull-colored nocturnal moths. Larvae are caterpillars that range in color from pale green to brown or black, often striped with white to yellowish lines from head to tail. Look for pruned turf.
Biology/Life Cycle: Complete metamorphosis. Egg, larva, pupa, adult. One brood a year. Hibernate in the egg or partially grown larval stage. Pupate in the soil.
Habitat: Grasses, vegetables and ornamental plants.
Feeding Habits: Feed mostly in the spring and early summer. Eat small grains, stems and foliage. Especially fond of corn, millet, and bluegrass, but will also eat other grasses such as bentgrass and bermudagrass.
Economic Importance: Destruction of plant foliage and entire plants. Especially destructive to young seedlings.
Natural Control: Parasitic wasps such as trichogramma, parasitic flies and ground beetles.
Organic Control: Releasing Trichogramma wasps before the worms appear is the best way to control these pests, but after the caterpillars appear and start to feed killing sprays are needed. Use Bt (Bacillus thuringiensis) products like Dipel or Thuricide, spinosad products or Garrett Juice with 2 ounces of orange oil added.
Insight: Armyworms are one of the few insect pests that will attack turf grasses; they can be a serious pest on golf courses using artificial techniques. They seem to appear out of nowhere. Flush out with soapy water to check for level of infestation.