Winter treatment for cucumber beetles?

Asked September 11, 2018, 3:19 PM EDT

My cukes have gotten hammered by beetles (striped and 12-spotted) for the past two years. Is there anything I can do this winter (like destroy eggs or nests) to knock their population down so I don't have such an infestation next year?

Benton County Oregon fruits and vegetables horticulture

1 Response

Hi there. Cucumber beetles are a tough one. There are generally two generations per year. Adult beetles overwinter in protected sites such as under debris or in woodlands. Be sure to clear all residual plant material from your planting beds at the end of the season. As soon as the weather warms they lay their eggs at the base of cucurbit plants. When you set your cucumbers out next year cover them immediately with row cover and leave it on until the plants begin to bloom. One paper I read suggested that you use an aluminum reflective plastic in conjunction with drip irrigation under it. The mulch repells the beetles and aphids. In the same document it was suggested to use straw mulch because it provided good habitat for wolf spiders which prey on the beetles. You can focus on killing adults NOW to reduce the numbers of adults that will overwinter and thus reduce the number of eggs laid next spring. Adults are susceptible to chemical control, once they lay their eggs in the soil in the spring there is no control that is effective against the larva in the soil.