Squash Vine Borer, and Flowers But No Squash Yet

Ever have a squash plant, healthy and beautiful, suddenly wilt, and shortly thereafter die? You’re not alone, as your squash planting has been visited by the squash vine borer. The adult looks like a wasp, but it is really a moth, who lays eggs on the squash stems. The larvae bore into the center of the stem, eating the insides until the plant wilts and dies.

Visit one of our Extension urban IPM entomology blogs Exoskeleton Express – to find out a little more about this common pest and what can be done to prevent it and treat infested plants. While row covers would keep the adult moth away, they will also keep pollinators away, too. Without pollinators, no squash!

As a matter of fact, one of the most common complaints I get regarding squash is something like, “My plants have been blooming but I’m not getting any squash.” Or, “My squash gets about 2 inches long and then rots – what disease do my plants have?”

The answer is, no disease, but rather no pollination. Often the problem is that the flowers start off mostly male (yellow flowers attached to long, skinny stalks). Of course, the males do not produce fruit. The female flowers have what looks like a tiny, baby squash right under the yellow petals. And, if you have both male and female flowers present, then they are not getting pollinated. Watch your pesticide use, since many are quite toxic to bees. Squash flowers are only open the first part of one day, closing up in the afternoon. If the morning time was windy and/or rainy, then there might not be much bee activity.

You can play the role of the bee – take the male flower stamens (has all the yellow pollen on the anthers) and swish them onto the stigma on top of the pistil in the female flower – do this for a couple of days, and you’ll soon be in squash production.

Comments are closed.