Squash Vine Borer

Squash Vine Borer

Damage caused by borer

Squash Vine Borer

This pest is only a concern for summer squash, winter squash, and pumpkins. It is often not a problem with cucumbers, melons, butternut squash, and watermelons. The borer can be very devastating to your plants, causing them to wilt and eventually die. The larvae bore into the stem and feed through the center of it. This blocks the flow of water causing the plant to wilt.

 

Start looking for this pesty borer in the adult form in late June into early July. The adult borers are about ½ an inch in length and look similar to a wasp. They have an orange abdomen with black dots and the wings are metallic green. You will notice them in one of two ways, you will see them flying around during the day or they make a very noticeable buzzing sound when flying. 

 

There are several ways to help reduce the chances of your plants becoming infected with the borer. It is best when several methods are combined. One method is to plant early as soon as the risk of frost is over or wait to plant your squash until July after the adults have finished laying eggs. Wrap a collar of aluminum foil around the stem to prevent egg-laying. Another method is to use floating row covers, which are a special breathable fabric tented over the plant. The cover is light weight so a structure does not need to be created, it will float on top of the plants. Remove the cover after signs that the adults are gone so that the flowers may be pollinated. However, do not use the cover if you have had problems with the borer in the past, as it may trap them in with the plants. Diatomaceous Earth can be sprinkled around the base of the plants, creating a barrier for the larvae. Insecticides may be used and treatment should start as soon as vines begin to run or when adults are first detected. Applications should be made every 7-10 days until the end of July and should be done on the stems, especially near the base of the plants. Applying product to the leaves will not provide protection. Insecticides that can be used include Bonide Neem Oil, Bonide Eight Flower & Vegetable Granules, or Bonide Captain Jacks Deadbug Brew.

 

If your plant is still infected, you may be able to save them. Look for the point of entry near the soil on the stem. Once found use a sharp knife to make a slit in the stem until you find the larvae. Remove the larvae and burry the stem under an inch of soil, being sure to keep it well watered. Roots should form, hopefully saving the plant. If your plant still succumbs to the borer, remove it as soon as possible and throw it out in the garbage.