Striped cucumber beetles start flying around even before many of our plants emerge. This means they are often there just as the cucumber, squash, pumpkin and melon seedlings push through the soil, eating off the stems and first leaves to emerge. Later, adults feed on leaves, vines and fruits that survive. Larvae feed on the roots of the plants, weakening them and making them susceptible to other problems.
One problem these beetles cause is a disease called bacterial wilt, a serious disease of many vine crops. The bacteria overwinters in the bodies of hibernating beetles which introduce the bacteria to the plants during feeding. Infected plants quickly wilt, the leaves dry, and the plants eventually die. Cucumber beetles also spread the squash mosaic virus.
Bacterial wilt and mosaic virus must be prevented since they cannot be controlled once the plant is infected. Inspect plants frequently for the striped cucumber beetle (the adult is about 0.2 in. long, tan in color with three black stripes down the back). Row covers provide some protection, but must be removed during pollination. Some resistant varieties are available, and there are a few products labeled for control of the beetle. Always read and follow pesticide label directions when used.