Adult cereal leaf beetles are metallic-black; the legs are brownish-yellow; and the area behind the head is reddish-brown. Length varies from 5 to 6 mm, the female being slightly larger than the male. The yellow larva is usually covered with a brown or black coating of fecal material.
Wheat, corn, fescue, ryegrass, millet, rice, other grains and grasses.
Larvae and adults are both voracious feeders. They prefer seedling plants or new growth on older plants. The larvae consume one to ten times their weight each day. Since larvae eat so much and rarely move from plant to plant, their damage is more noticeable than that of the adults. Seedlings in the one-leaf stage are often killed by a single larvae per plant. Both larvae and adults feed between the leaf veins. Adults chew completely through the leaf while larvae feed superficially. The tips of damaged leaves turn white, giving infested fields an overall whitish appearance.
Cereal leaf beetle overwinters as an adult. Adults emerge and lay eggs in early spring in grains. Developing larvae feed and develop on spring grains. Larvae pupate in the soil and emerge in summer and fall. There is only one generation per year.
Control with insecticides is very effective. Treat wheat for cereal leaf beetle when there is an average of one insect per two leaves and defoliation exceeds 15 percent.