The larva is a white grub with a brown head. Adult weevils lay eggs on the developing bean pods in the field. In 3 to 30 days the tiny grubs emerge and make their way into the seed. Here they feed until mature, and pupation occurs. Indoors in stored seed multiple generations occur and breeding continues as long as there is any food left in the beans and the temperature is suitable for reproduction.
Bean seed used for cooking purposes is dry when harvested.
Shells are then removed. The time to take action is right after the dry beans are harvested. Either freezing or oven heating can control the weevils. Beans or peas should be placed in a freezer at 0 degrees F or less for four days. The beans may be stored in the freezer if space permits, or they may be stored in glass jars or metal containers.