Although native to the U.S., bean leaf beetles have been only been considered an economic pest of soybean since the late 1980s. Adults feed on snap beans, dry beans, peas, alfalfa, clover and even corn, but strongly prefer soybean. Bean leaf beetle adults will feed on leaves, cotyledons, and pods, while the larvae feed on the roots; adult leaf-feeding injury is usually round or oval holes about the diameter of a pencil.
Iowa State University
Hodgson, Erin W., "A Harsh Winter for Bean Leaf Beetles" (2009). Integrated Crop Management News. 674.