Small Group Session: Cabbage Family -- Specifically, Flea Beetles
The farmers present said that flea beetles were their key pests on cabbage family crops. Caterpillars were controlled with Bacillus thuringiensis if needed. Each farmer described his or her strategy for dealing with flea beetles. These included: row covers, vacuuming with a backpack leaf vacuum, botanical insecticides, and growing cabbage family plants only in the fall.
What Do We Know About Flea Beetles
Kimberly Stoner, an entomologist from Connecticut, reviewed information about flea beetles. It is important to understand that there are many species of flea beetles, and that the flea beetles on cabbage family crops are different from those on tomatoes or eggplant. The species which is most commonly a pest on cabbage family plants, Phyllotreta cruciferae, overwinters as an adult in and around vegetable fields, and becomes active again early in the spring, feeding on cruciferous weeds. The most severe damage is to seedlings early in the season, and may be avoided by starting plants in the greenhouse or under row cover. There are few effective natural enemies of flea beetles, as far as we know, in the U.S.
Some possible approaches to managing the behavior of flea beetle adults might be:
- trapping with sticky traps baited with mustard oil or some less concentrated form of mustard,
- interfering with beetle movement by intercropping non-host plants, or
- planting less preferred cabbage family species or varieties.
Discussion: Cabbage Family Crops and Flea Beetles
Additional possibilities brought up in the discussion were:
- using water pan traps instead of sticky traps to trap beetles,
- using the flea beetle aggregation pheromone as an attractant, and
- trapping beetles around early-season cruciferous weeds.