Description: Adults vary in color but are typically reddish brown to yellowish with four black spots and marginal stripes. Spots may not always be present but a black, triangular-shaped marking is always present on the forward margin of the wings. Adults are 5 to 6 mm in length. Larvae are white and cylindrical with a black head and anal shield and reach a maximum length of 10 mm.

Hosts: Soybeans, peanuts, and various legume crops and weed species.

Damage: Damage to soybeans occurs primarily by leaf-feeding adults, however, adults will occasionally feed on developing pods. Larvae feed on plant roots but are not considered an economic problem on soybeans. Adults generally prefer to feed on the youngest plant tissue available. Defoliation is recognized as small, round holes between major leaf veins.

Life Cycle: Bean leaf beetles overwinter in leaf litter and other vegetation and emerge in early spring. Females lay 175 to 250 eggs in clusters of 12 to 24 in the soil at the plant's base. Eggs hatch in about a week, and larvae feed on roots for 2 to 4 weeks. The pupation period lasts about seven days. As many as three generations occur per year in southern areas.

Bean leaf beetle
Photo by: David Adams, UGA

Bean leaf beetle
Photo by: NC State University