Did you find your vining crops suddenly wilting and dying last summer? If so, you may be suffering from a squash vine borer. This clearwing moth is a serious pest of vine crops such as summer squash, winter squash and pumpkins.
In mid-June, the squash vine borer emerges from cocoons in the ground where they have overwintered. These moths lay eggs singly at the base of susceptible plants. About a week later, the eggs hatch and the larvae bores into the stem to feed, blocking the flow of water to the rest of the plant. The larvae, which grow up to an inch in length, have a brown head and a cream colored body, feed for four to six weeks. Then exit the stems and burrow into the ground to start the whole life cycle again next summer.
The first symptom of infestation is wilting of the effected plant. If you notice sudden wilting, check for holes near the base of the plant. There will also be moist greenish or orange sawdust-like material around the hole. The base of the plant may also become mushy. More than one borer can attack each plant.
Unfortunately, it can be difficult to control the borers once they are in the stem. So you can try to exclude the adults from laying their eggs on your vine crops by placing a floating row cover over your vine crops when they start to vine or in mid-June. Keep the barriers in place for about two weeks. Make sure the cover is securely placed so that the insects cannot crawl under the material. Just remember, do not use covers when plants are flowering, since bees will not be able to visit these plants.
Another option is to plant vine crops that are less likely to be attacked by this insect such as butternut squash, cucumbers, melons, and watermelons. Also, consider a second planting of summer squash made in early July which will mature after adult borers have finished laying eggs. Once you do see damage, pull and destroy those plants. Remember, the insects may overwinter near debris.
If you notice a borer in your vine, use a sharp knife to cut a slit in the affected stem until you locate the insect. Remove the borer, then mound moist soil over the cut area and keep the spot well-watered. While this is a last ditch effort, roots may grow along the cut stem which will allow the plant to survive.
Do you love tomatoes? How about growing them? Amanda Sears, Madison County Horticulture Agent, will be teaching a class called "Terrific Tomatoes". This class will discuss the good, the bad and the ugly details of growing tomatoes. This class is on April 16, and will be offered twice, at 12 noon and 6 p.m. at the Madison County Extension Office (you only need to attend on session). If you plan to attend, let us know by calling 859-623-4072.
Educational programs of the Cooperative Extension Service serve all people regardless of economic or social status and will not discriminate on the basis of race, color, ethnic origin, national origin, creed, religion, political belief, sex, sexual orientation, gender identity, gender expressions, pregnancy, marital status, genetic information, age, veteran status, or physical or mental disability.