Abstract:
Armyworms are the larvae (caterpillars) of the moth Pseudaletia unipuncta Haworth. This insect is a serious pest of turf, forage, and seed grasses; small grains; and corn throughout North America. Armyworms can cause sudden, extensive damage to these grasses and grasslike plants. Note that the armyworm does not feed on clover, alfalfa, or other broadleaf plants in mixed grass–legume stands. Armyworm outbreaks can occur suddenly, and crop and economic losses can be substantial. If armyworms are not detected and controlled early, they are very difficult to control, even chemically.
In western Oregon, armyworm outbreaks are cyclic. They occur
every 7 to 15 years, from August through October, and may persist
for 1 to 3 years. Grasses and corn are the crops most affected.
