Crucifer flea beetle

The crucifer flea beetle (Phyllotreta cruciferae) is a significant pest belonging to the order Coleoptera and the family Chrysomelidae. It is a widespread insect known for its ability to devastate various brassica crops during their most vulnerable early growth stages.

This pest primarily attacks host plants including canola, mustard, cabbage, radishes, and rutabagas. Infestations typically occur during the seedling stage, where rapid feeding can result in the complete destruction of cotyledons and primary foliage, often leading to plant death.

The life cycle begins with overwintering adults that emerge in early spring. Females deposit eggs in the soil near the base of host plants. The larvae feed on the roots, followed by a pupal stage in the soil before the new generation of adults emerges to feed on the leaves of plants.

Damage is characterized by small, distinct pits or "shotholes" in the leaf tissue, created by the adults' feeding habits. If population densities are high, these small holes coalesce, causing the leaf tissue to skeletonize, which significantly inhibits the photosynthetic capacity of the plant.

Effective management strategies include cultural practices such as early seeding, crop rotation, and maintaining high soil fertility to encourage rapid plant establishment. Chemical control involves the use of seed treatments or foliar insecticide applications when scouting indicates that the economic injury level has been exceeded.