In Pennsylvania the squash vine borer will only have one generation a year. In many southern states two generations are common. The squash vine borer injures plants by tunneling through their stem, which interferes with nutrient transfer in the plant. Borer feeding weakens plants providing the opportunity for secondary infection. Plants damaged by the squash vine borer will wilt.
Examination often reveals shiny green-to yellow colored frass within the stem.
Often frass will protrude from any damaged areas of the stem. If vine senescence occurs early, the borer may tunnel into the fruit. Not all fields will have problems with squash vine borer. Fields that have been attacked in the past are most likely to have squash vine borer problems in the future. When infestations of squash borer are caught early it is often possible to save the plant.