Armyworms are found throughout the Southwest, Southeast and Northeast regions of the United States. While the “spring” armyworm is most damaging in spring and early summer, the “fall” armyworm does the most damage in late summer and declares war on Oklahoma until the first frost of winter. The infestation begins in late June as adult moths bring arrive from the south. Upon their landing, adult females lay masses of eggs. They can lay up to 1,000 eggs at a time. Larvae hatch out early July and will feed underground for two to three weeks before digging into the soil to pupate. The new generation of moths will emerge about two weeks later. This reproductive cycle will continue through October allowing several generations of armyworms to populate the region.

To detect armyworms, examine plants at night with a flashlight or douse lawn with soapy water, which will bring pests to the surface. Armyworms mainly migrate to a food source in the cool of night, so they can be hard to detect until they begin to inflict damage by eating leaves.