Spodoptera spp., Mythimna unipuncta
Caterpillars that feed in large groups, moving across fields like an army. Can cause severe defoliation overnight. Several species affect different crops.
Smooth caterpillars 1-2 inches long, green to brown with stripes. Move in masses. Adults are gray-brown moths. Feed mostly at night.
Rapid defoliation. Chewed leaves and stems. Damaged corn ears and tassels. Bare patches in lawns. Plants eaten to ground level.
Multiple generations per year. Cannot overwinter in cold climates. Moths migrate north in spring. Eggs laid in masses, larvae feed 2-3 weeks.
Monitor for egg masses and young larvae. Maintain healthy turf. Remove weedy borders. Scout after storms (moths ride weather fronts).