Sweet Potatoes: Sweet Potato Flea Beetle

Problem
Yellow irregular channels are chewed in the surface of the leaves. Tiny (1/16 inch), black beetles jump like fleas when disturbed. Shallow, dark tunnels scar the surface of the root.

Analysis
(Chaetocnema confinis)

These beetles jump like fleas, but are not related to them. Both adults and immature flea beetles feed on sweet potatoes. The immature beetle, a legless white grub, feeds on the surface tissue of the roots, making them unattractive but still edible. Adults chew channels in leaves. Flea beetles are present nearly everywhere sweet potatoes are grown. They are most damaging to young plants. Adult beetles survive the winter in soil and garden debris. They emerge in early spring to feed on weeds until slips are set in the garden. Grubs hatch from eggs laid in the soil and feed for 2 to 3 weeks. After pupating in the soil, they emerge as adults to repeat the cycle. There are several generations a year.

Solution
Control flea beetles on sweet potatoes with an insecticidal spray containing methoxychlor when the leaves first show damage. Watch new growth for evidence of further damage, and repeat the treatment at weekly intervals as needed. Clean all plant debris from the garden after harvest to eliminate overwintering spots for the adult beetles. Treat soil with an insecticide containing chlorpyrifos.