Origin:
Possibly a native of North Africa, but now cosmopolitan.
Biology:
This species is one of 3 in the genus found in North America, and it may occur anywhere dried legumes are kept in storage. It is likely native to Europe or Asia since a great many other species occur there in the genus, but this species is now cosmopolitan. Females deposit eggs on the growing pods of beans and the larvae bore inside to feed there for six to eight weeks, depending on the temperature. The larva then pupates inside the bean and emerges as the adult, with one generation per year. These beetles cannot reproduce on dried beans but must deposit eggs on the pods of beans during growth. The larvae feed within the developing bean in the pod and continue their presence while dried and in storage. These beetles also may feed on other legumes such as vetch, a weed plant.
Identification:
The adult beetles are large for the family, just under ΒΌ inch long and a dark gray-brown and covered with very short hairs. The elytra have many small yellowish or whitish spots on them and the exposed abdominal segments also may be a yellow color. Typical of the bean weevils the elytra are short and leave the last few segments of the abdomen exposed from above. The head tends to tuck under the thorax, particularly on dead specimens where it curls downward. The antennae are orange at the base and the front legs are reddish-orange.
Characteristicts Important to Control:
Control of these stored food pests relies on recognizing the likely food products they infest, searching to find the infested materials, and disposing of that source. Good stock rotation will help to prevent the beetles from beginning the infestation. In a home many unusual sources need to be investigated, including decorative items that have dried legumes in them. Insecticides may be needed only to eliminate any remaining adult beetles that are wandering about.
