Armyworm Invasion Hits Kansas Crops

Fall armyworms have been detected in Kansas since mid-June and their numbers continue to rise. According to pheromone trap counts, the moths are now present throughout the state. Another potential fall pest, army cutworms, have also been spotted in western Kansas since early September.

Army cutworms migrate into Kansas from the Rocky Mountains in the fall and can cause significant damage to crops such as alfalfa, wheat, and triticale. The moths typically lay 1,000 or more eggs, which hatch into caterpillars that feed on plants until cold weather forces them underground.

By next spring, the caterpillars will complete their growth and burrow into the soil to pupate, emerging as sexually immature adults that migrate back to the mountains. The moths' presence in Kansas is likely to continue throughout the fall, with trap counts indicating significant activity in northwest Kansas.