TUBER FLEA BEETLE

A, Life stages: a. eggs; b, larva; c, pupa; d, adult. B, Damage to potato foliage; e, beetles. C, Damage to potato. (A. greatly enlarged; B and C. natural size.)

TUBER FLEA BEETLE

The tuber flea beetle is one of several kinds of flea beetles that attack potatoes. Its grub prefers to feed on the tubers; other flea beetles feed mostly on the roots. The flea beetles look alike. Some are destructive to other crops. The tuber flea beetle, however, is a pest only in Washington, Oregon, Colorado, and Nebraska, and causes little damage to crops other than potatoes.

The flea beetle jumps like a flea and quickly disappears when disturbed. The adult tuber flea beetle eats small round holes in the leaves a type of injury characteristic of all flea beetles. The adult female enters the soil near the base of the plant to lay her eggs, which hatch in 5 to 8 days into slender white grubs, or larvae, which feed on the roots and in the tubers. Injury to the latter may take the form of roughened trails on the surface or tiny brown tunnels, extending as far as three-quarters of an inch into the tuber. After feeding for 2 or 3 weeks, the mature larva enters the inactive, or pupal stage, which lasts 10 to 14 days. At the end of this time the young beetles emerge to begin a second generation. Sometimes a second generation is completed and a third begun during the season. The insect passes the winter as an adult in the soil and emerges in May or June to begin feeding on the next season's crop.

Control: Apply a 5 percent DDT dust at 20 to 35 pounds per acre. This will also control most of the other insects which attack potato foliage. When power dusters are used, attach a lightweight canvas apron, 12 to 20 feet long, to the boom of the duster to help prevent the dust from drifting away. If sprays are preferred, apply 2 pounds of 50 percent DDT wettable powder per acre. With ordinary spray equipment the wettable powder should be applied in 80 to 125 gallons of water at a pressure of at least 250 pounds per square inch, preferably with three nozzles to the row.