A. It sounds as though you have Squash Vine Borers. These wasp-like insects can inflict serious harm to your squash plants. Sections of stems may suddenly wilt, and stems appear rotted or chewed at the soil. You know for sure at this point that you have squash borers. Once the plant wilts, it is hard to save it.

Squash Vine Borers are actually a moth (Melitta cucurbitae) in the order Lepidoptera and family Sesiidae. They fly during daylight hours. The moths are quite attractive, about an inch long, with a brilliant orange and black abdomen and matching “hairy” hind legs.

Their front wings are opaque and the hind wings are clear with dark veins. Moths emerge in early summer and lay eggs on the squash stem, normally close to ground level. The larvae hatch and tunnel into the squash stem, with the subsequent demise of the plant. There are one or two generations per year.

Here are some ways that may help you increase the life span of your squash plant so you get the full harvest you deserve. Covering the plant with floating row covers until female flowers are open can protect young plants. Floating row covers are made of superlight, spunbound polypropylene which allows light and water through but serves as an impenetrable barrier for insect pests. These may be found in garden catalogs and some garden centers.

Once that cover is removed, I highly recommend spraying a product containing Bt or pyrethrums along stems of plants. Recently I read in Rodale’s book titled “Garden Answers, Vegetables, Fruits and Herbs” an excellent way for preventing borer problems is to wrap a pair of pantyhose around the stem and the base of the plant. I haven’t tried it and it certainly would be labor intensive but it is worth trying.

There are some squash plants that are borer-tolerant cultivars and I have found them in seed catalogs. Generally speaking, catalogs offer detailed information on different seeds and their strengths and weakness to different diseases and insect problems.

So let’s get planting and start enjoying some delicious squash dishes.

Sudden wilting of stems is a common symptom on plants
infested with larvae of the Squash Vine Borer.
Larvae bore into the stem and feed on tissue that
disrupts the flow of water and nutrients.

Attack by squash vine borer is characterized by sudden
wilting of one or more stems on the plant.

Larvae are fat grub-like caterpillars with a white
wrinkled body and a brown head.