Bean Leaf Beetle

bean leaf beetle
bean leaf beetle     Photo: Katja Schulz :

Primarily a soybean pest, these beetles also chew holes in the leaves of snap beans and dried beans. A serious infestation can severely damage or kill plants.

The coloration of bean leaf beetles varies from yellowish-green through tan, orange and red. To confirm the identity, look for a black triangle at the base of the “neck” and four black spots on the wing covers. Adults emerge in spring to begin feeding on bean seedlings. They lay orange eggs on the soil near the base of plants.

The white larvae feed on plant roots, but they rarely inflict serious damage. A second generation of beetles emerges in midsummer and feeds on bean pods. The damage they cause can lead to disease. These beetles overwinter in plant debris and grasses, and populations are often much reduced after a cold winter. These beetles are an occasional garden problem throughout the eastern U.S.

Prevention and Control

  • In spring, delay planting until after the first generation of adults emerges from the soil.
  • Adult beetles are usually most active in the afternoon. Handpick them and drop them into a jar of soapy water.

Last updated: 03/15/2024