Crucifer Flea Beetle

The crucifer flea beetle is a non-native insect pest that accidentally was introduced into North America during the 1920s. Phyllotreta cruciferae now can be found across southern Canada and the northern Great Plains states of the United States.

The adult is a small (about 1/32 to 1/8 inch), oval-shaped, bluish-black beetle with numerous dimples on the wing covers. The whitish larva is wormlike and approximatley 1/8-inch in size, with tiny legs and a brown head.

The crucifer flea beetle has one generation per year. Adult flea beetles overwinter in leaf litter of shelterbelts and grassy areas. They emerge from the overwintering sites during early spring as temperatures reach up to 57 F.

Overwintered adults feed on seedling cruciferous host plants.... read more Summer adults feed on the pods of canola, mustard and cruciferous weeds.

Volunteer canola and wild mustard are usually the first available host plants, with the beetles moving into the new canola fields as the crop emerges. Overwintered adults are usually active in the fields until late June, feeding on the foliage and depositing their eggs in the soil. The larvae can be found in the root zone of host plants during June and July. The pupal stage occurs from early to mid-July. The new generation, or summer adults, are present from late July to early September. They can be found feeding on the pods of canola, mustard, and cruciferous weeds. The summer generation will move to overwintering sites in early fall.