Flea Beetles

Flea beetle adults are small (about 0.125 inch long), shiny, hard beetles with enlarged hind legs that allow them to jump. Different species (e.g. palestriped flea beetle and potato flea beetle) vary in color and markings. Larvae live primarily in the soil, although larvae in a few of the species may mine leaves or plant stems. Larvae are pale yellow to white with short legs and dark, hard heads. Older larvae may resemble small wireworms.

Adult flea beetles feed on the undersides of leaves leaving small pits or irregularly shaped holes on the leaves. Large populations can kill or stunt seedlings. Older plants rarely suffer economic damage, although their older, lower leaves may be damaged. Adults do most of the damage. Most flea beetle larvae feed on roots, but this activity is not usually of economic concern in peppers.

Flea beetles are common seedling pests, and monitoring newly emerged seedlings is critical for detecting a damaging population. Weed control around the field and using transplants also help to minimize damage by these pests.

Remove weeds along field margins and deeply disc plant residue in infested fields after harvest. Pay particular attention to cruciferous (Brassicaceae) weeds and crops such as canola, which are common hosts from which beetles can migrate into pepper fields. Transplanting peppers usually avoids the problem unless beetle populations are extremely high.

Cultural controls and sprays of pyrethrin are acceptable for use on organically certified produce.

Check newly emerged seedlings or recently planted transplants for flea beetle damage at least twice weekly until plants are well established. Relatively low populations can cause economic damage when plants are in the cotyledon or first-leaf stages. Once plants have five leaves they can tolerate several beetles per plant without damage. Older plants are even more tolerant. Seedling pepper plants and young transplants do not tolerate flea beetle damage well, and they may be killed if the weather is especially hot, dry, and windy. Damage is generally greater to seedlings than to transplants.

Monitor for flea beetles soon after transplanting or after plants emerge. Treat for flea beetles when small holes show on seedlings or on new transplants. The percentage of plants affected and forecast weather conditions will indicate the need to treat. Once established, plants can overcome moderate flea beetle feeding. If flea beetles are migrating to the pepper field, spot treatment of outside rows or borders may be sufficient. Baits are not effective. One insecticide treatment is usually all that is required.