A small yellow-and-black striped beetle (Leptinotarsa decemlineata) that is a major agricultural pest. or potato bug Leaf beetle (Leptinotarsa decemlineata, family Chrysomelidae) native to western North America. It began feeding on the leaves of cultivated potatoes when the plants were introduced into western North America, and by 1874 it had become an important and widespread pest. It has a hemispherical body, about 0.4 in. (10 mm) long, and is orange-red or yellow, with black stripes on the wing covers. Depending on climate, potato beetles may produce one to three generations each year