Adults are oval-shaped, robust, and 4–6 mm long. They are shiny metallic with green, blue, purple, rust brown, or bronze undertones. In their native range, they feed on common St. Johnswort foliage in early summer as plants are flowering, laying eggs on basal re-growth as common St. Johnswort mature growth is senescing. Orangish-gray larvae hatch in early spring and feed on common St. Johnswort foliage. They are up to 6 mm long and develop through four instars. Pupation occurs in the soil in late spring. There is one generation per year.