A to Z of Pests

Four Spotted Bean Weevil

Bruchus quadrimaculatus

Appearance

• Adult 4mm long.
• Stout-bodied, shortened wing covers and a short broad snout.

Lifecycle

• The female lays eggs into stored beans or into seed pods in the field.
• When fully grown, the larvae form pupae in the eaten-out cavity of the bean.
• Young adults chew their way out of the beans, mate, lay eggs and begin a new generation.
• As many as six generations are produced in a single year.

Habits

• The adults attack legumes either in storage or in the field and may completely destroy them.
• Breeding continues in stored products as long as the products maintain their nutritional value and the storage environment is warm.