| Life Cycle: | The adult cabbage flea beetle over winters in the soil and in leaf litter in the area of the host plant. It is very small, only three millimetres and a shiny, dark green - almost metallic black. It emerges in the spring when it will mate and begin laying eggs. The adults die off by late June or early July. The larvae hatch at about the same time. The burrow beneath the soil and feed on the roots of host plants before they pupate. The new generation of adults emerge at the end of July or early August. This generation will feed on host plants and then seek shelter in the plant debris in preparation for over wintering. |
| Host: | As the name suggests the cabbage flea beetle prefers cabbage and other members of the cruciferae family; however, they can also be problematic for tomato, potato and corn plants. |
| Bio Region: | The cabbage flea beetle can be found throughout North America. |
| Damage: | Flea beetle damage is most serious in the spring when the adults that over wintered begin to feed. They chew small pin holes through the leaves of the host. In serious infestation the leaves may look skeletonized. Damage is at its worst at the cotyledon stage or when transplants are too young to have sufficient foliage to survive the attack. Larva will feed on the root causing additional damage. The summer generation of adults can also do damage to late season plantings or transplants. |
| Management: | Because flea beetles over winter in the leaf litter of the host plants, rotation is a valuable strategy; however this is only true if the producer can be sure that the field into which a cole crop is rotated was free of host plants or weeds the previous season. Trap crops can be used to attract flea beetles away from the commercial crop. This approach is less effective if the commercial crop is particularly attractive to the flea beetle. Row covers are a very effective barrier provided they are put on before the adults emerge. Some adults will emerge from inside the row cover unless crop rotation is practiced. Removing leaf debris at the end of the season helps minimize the number of locations the beetles can over winter in. |
| Controls: | Cabbage flea beetles have several predators. The brachonid wasp will help limit the infestation and is commercially available. So are entomopathogenic nematodes which attack the larvae of the beetles thereby reducing future populations. Naturally occuring formulations of pyrethrin are allowed. Rotenone is effective but the national standards restrict its use. It must be part of a bio-rational pest management program. The use of spinosad formulations such as Conserve and Entrust have been effective in controlling some varieties of leaf beetles. Pyrethrum is also approved for use on flea beetles. It is important to ensure that any insectide has both a pest control product number and is allowable by your certification body. |
