In a week or more the eggs hatch and the larvae work their way to the cucurbit. Here they burrow into the root and underground stem tissue and feed for about a month. The mature larva constructs an earthen cell a few inches below the soil surface and pupates. The adult beetles emerge in late August or September and feed on pollen until killing frosts occur. This insect is difficult to control because the adults attack plants close to or even below ground level.
Control is important, however, to prevent bacterial wilt disease.
Fall cleanup by disposing of old cucurbit plants reduces potential habitat for the beetles. Researchers are working on breeding varieties of squash that show resistance to cucumber beetles. Mechanical barriers such as row covers or wire or cloth screen protectors made in the form of cones or hemispheres can keep beetles out. Be sure edges are sealed to the ground so that insects do not move in underneath them. Place barriers over newly set transplants or newly seeded beds.