The Squash Vine Borer or simply “Vine Borer” is one of the most dreaded insects for Cucurbits. The Cucurbita family includes pumpkins, squash, cucumbers, and watermelon plants. An infestation of Squash Vine Borers (abbreviated SVB’s) spells a quick end to your season for these crops. And, it may hardly qualify as an “infestation”. As a matter of fact, all it takes is one or two SVBs per plant. The adult is a flying insect that leaves its eggs on the underside of plants like pumpkins. The squash vine borer eggs hatch into larva that travels down the leaf stems to the vine. It is the larva of Squash Borers that do the damage. The larva drills into vines, most often near the base of the plant. Once inside, they eat the vine away from the inside out, ultimately severing it.
If Squash Vine Borers exist in your area, then the use of insecticides is the only real method of prevention and control. Using insecticides specifically effective against them is all but a necessity when growing members of the Cucurbita family. They include pumpkins squash, watermelon, and cucumbers.
The female lays her eggs on the underside of leaves. The eggs hatch and the larva (grub-like insect) travels down the leaf stem. It then bores a hole to enter the vine. Once inside, the SVB is surrounded by food….your vine!
Here are the key signs that you have a borer infestation:
If you have a healthy crop, and it begins to wilt, borers could be the problem.
If the fruit is growing, then unexpectedly stops, you may have SVBs.
The undersides of leaves have squash vine borer eggs.
Upon close inspection, you find holes and/or sawdust-like material on the vine, you definitely have Squash Borers.
If borers are known to exist in your area, we highly recommend preventing these insects from affecting your crops. That means using insecticides.
Not all insecticides will be effective. Read the back of the insecticide label, to be absolutely certain that it is effective against them. Follow the instructions on the label carefully for application rates, method, and frequency of use.
Insecticides need to be applied early before the grub-like larva enters the vine.
Once a squash borer enters the vine, insecticides cannot reach it. The only thing you can do is to remove it “surgically” from the vine. Leaving the borer inside your vine is not an alternative. Of course, removing it can cause further harm to the plant.
To extract the squash vine borer, find the entry hole. Use a sharp knife and slowly slice lengthwise, up and down the vine, until you spot the vine borer. Remove the borer with the tip of your knife and destroy it. There could be more than one in the vine. So, search for more.
After “surgery”, apply a fungicide to the wound. Thus, with a little luck, your season has been saved!