The female lays her eggs in immature pea pods; one or two eggs per pod. The larva consumes the peas from the inside, and eventually pupates inside one.

The adult leaves the pea through a 5-mm-diameter exit hole. In the wild, the adults feed on pollen, among other things. This species occurs inside stored peas, or as already emerged adults in which case the exit holes in the peas can be used as signature of damage. The beetle is a potential pest of pea that can cause detrimental crop losses. It does not occur regularly or in large amounts in Finland today, but possibilities of spread via global seed trade are realistic, since it lives inside the pea during all of its life stages. The adult is also capable of flying up to 5 km distances for suitable host plants and possibly hibernating in the wild. The species has had populations in Finland since the 1940’s and observations were made also in 2021 at a pea field in Finland.

Hernepiilokas – Bruchus pisorum