The most common problem encountered when growing beans, Mexican bean beetle (Epilachna varivestis) adults and larvae feed on the leaves and pods of all types of beans. Badly hit plants produce poorly because so many leaves are consumed; bean pods can also be seriously damaged. Organic controls for. The Mexican bean beetle (Epilachna varivestis) is one of the most destructive insect pests of beans in the eastern United States and portions of the itinerarte.info the adult and the larval stages feed on the undersides of the leaves, and sometimes will attack young pods and stems. Adult Mexican bean beetles are oval yellowish-brown to copper-colored beetles with 16 black spots on their wing covers. They are ¼-inch long and look something like .