Veronica Yurchak, Vegetable Specialist, University of Maryland; vjohnso4@umd.edu
Congratulations to Keith McGowan and others for correctly identifying this as a squash vine borer adult! These moths began emerging and laying eggs in cucurbit fields in recent weeks. Once hatched, larvae bore into the base of squash plants and feed internally, causing dieback of the vine or main stem. Infested plants can have more than one larva, and management can be difficult especially in small-scale production where only a few moths can infest a high percentage of plants. Thus, smaller plantings are more likely to lose entire crops than commercial fields with a higher number of plants. There are several pyrethroids labeled for vine border control, but keep in mind that frequent pyrethroid use can flare aphid and mite populations.
