Both striped cucumber beetles (Acalymma species) and spotted cucumber beetles (Diabrotica species) are common pests of vegetable plants. It is important to control these beetles because they may infect plants with 2 serious diseases that damage and may kill cucurbits (such plants as squash, melons, and cucumbers): squash mosaic virus (see Mosaic Virus) and bacterial wilt (see Bacterial Wilt). Adult beetles survive the winter in plant debris and weeds. As soon as vegetable plants are set in the garden in the spring, the beetles attack the leaves and stems, and may totally destroy the plants. Adults lay their yellow-orange eggs in the soil at the base of the plants. The grubs that hatch from these eggs eat the roots and the stems below the soil line, causing the plants to be stunted or to die prematurely. Severely infested plants produce little fruit. The slender white grubs feed for several weeks, pupate in the soil, and emerge as adults to repeat the cycle. There is 1 generation a year in northern parts of the United States and 2 or more in southern areas.
Treat the plants with an insecticide containing pyrethrins, carbaryl, or diazinon at the first sign of the beetles. Make sure that your plant is listed on the product label.
