Bean weevils

The bean weevils or seed beetles are a subfamily (Bruchinae) of beetles, now placed in the family Chrysomelidae, though they have historically been treated as a separate family.

Bean weevils are generally compact and oval in shape, with small heads somewhat bent under. Sizes range from 1 to 22 mm for some tropical species. Colors are usually black or brown, often with mottled patterns. Although their mandibles may be elongated, they do not have the long snouts characteristic of true weevils.
Adults deposit eggs on seeds, then the larvae chew their way into the seed. When ready to pupate, the larvae typically cut an exit hole, then return to their feeding chamber. Adult weevils have a habit of feigning death and dropping from a plant when disturbed.