Tuber flea beetle (Epitrix tuberis), Coleoptera

Tuber flea beetle biology & life cycle

Adults emerge and feed on the potato foliage in May and June; then they lay eggs from which larvae hatch, usually in late June. The larvae remain in the soil and feed until mid-July when pupation occurs. Potato flea beetles feed on leaves and stems, resulting in leaves with a shot-hole appearance. Flea beetles may spread bacterial pathogens and the spindle tuber viroid. Foliar damage from these beetles is seldom extensive enough to be of concern, but may indicate future damage to the tubers. The larvae feed on tubers, resulting in a pimpled surface and small brown tunnels extending 0.06 to 0.25 inch into the tuber. Similar damage is caused by the tuber flea beetle; i.e., adults feed on foliage causing small round holes, which gives the leaf a shot-hole appearance. The larvae feed on potato tubers causing surface "tracking" or small tunnels about 0.2 inch deep. This tuber injury may reduce marketability and reduces storability.These flea beetles generally overwinter as adults in or on the soil in protected places. In most of the United States, two generations per year are possible, while in much of Canada, only one generation is common.

Identifying Tuber flea beetle

Tuber flea beetle: larvae

Mature larvae are about 0.2 inch long and white with a brown head.

Tuber flea beetle: adult

Potato flea beetle adults are small , about 0.1 inch in length, metallic greenish brown to black in color. They tend to jump like fleas when disturbed. They are slender, whitish, and about 0.25 inch long when mature. The tuber flea beetle adult is also small, only about 0.1 inch long.

Tuber flea beetle: management

Flea beetle populations can be reduced through regular crop rotations; populations will tend to build up with repeated cropping. Separation from other fields and freedom from volunteer potatoes can also help to minimize levels

Earlier crops tend to be less affected than mid to late crops due to lower beetle populations and damage symptoms may be reduced or less apparent.

Chemical controls can be effective in reducing egg-laying adult populations and the subsequent numbers of emerging larvae. Spraying should be based on monitoring and economic threshold populations. Chemical controls are most effective when applied early in the season. Spraying to control the adults prior to egg-laying is the only option, as spraying to control larvae is not possible.

Source: Alberta Agriculture