Squash Borers . . .

One day . . . . beautiful and healthy vines.
Next day . . .  withered and detached from the ground.
'Borers' had eaten the vines from the inside.  (Though they are not supposed to attack cucumbers, we have lost them, too.)


From the University of Minnesota :

The adult borer resembles a wasp. It is about 1/2 inch long with an orange abdomen with black dots . The first pair of wings is metallic green while the back pair of wings is clear, although that may be hard to see as the wings are folded behind them when they at rest. Eggs are flat, brown, and about 1/25 inch long. The larvae are white or cream-colored with brown heads, growing to almost an inch in length .


The tragedy begins with squash vine borer adults emerging from cocoons in the ground.
Squash vine borer adults are good fliers for moths and resemble wasps in flight. These moths are unusual because they fly during the day while nearly all other moths fly at night.

Soon after emerging, squash vine borers lay eggs singly at the base of susceptible plants. Approximately one week after they are laid, the eggs hatch and the resulting larvae bore into stems to feed. The larvae feed through the center of the stems, blocking the flow of water to the rest of the plant. The larvae feed for four to six weeks, then exit the stems and burrow about one to two inches into the soil to pupate. They remain there until the following summer. There is one generation per year.

Often the first symptom of a borer attack is wilting of affected plants. Wilting may occur only in strong sun at first,   but if the problem is left unchecked, the plants eventually collapse and die. Closer observation of a wilting plant often reveals holes near the base of the plant filled with moist greenish or orange sawdust-like material called frass.  Over time, the base may become mushy or rot away altogether. Several borer larvae may attack a single plant.


Squash vine borers are challenging to prevent or manage. Use integrated pest management (IPM) methods for the best results. Most management options are limited to control the hatching larvae before they enter the plant. Once the larvae invade the stem, it is difficult to treat squash vine borers. Home gardeners can take a proactive stance against squash vine borers by monitoring your squash for the presence of adult borers starting the last week of June. Monitoring tells you if and when squash vine borers are present. This information helps you determine what further management measures may be necessary. There are two methods for detecting squash vine borer adults. The first is actual observation of adult activity in the garden. These moths are conspicuous insects when flying and easy to detect; watch for them when you're in your garden. In addition, the adults make a very noticeable buzzing sound when flying that is easy to detect while in the garden.



You can also use yellow trap pans to detect squash vine borer adults. This can be any container (e.g. pan, pail, bowl) colored yellow and filled with water. Because squash vine borer adults are attracted to yellow, they will fly to the container and be trapped when they fall into the water. Place traps by late June, checking your traps at least once a day. When you notice squash vine borer adults in your traps you know they are active and it is time to take further action.

Plant vine crops that are usually not attacked by squash vine borers, such as butternut squash, cucumbers, melons, and watermelons.

A second planting of summer squash made in late June or arly July will mature after adult borers have finished laying eggs.


Promptly pull and destroy any plants killed by squash vine borers.

You can physically exclude adult borers by placing floating row covers over your vine crops when they start to vine (or for non-vining varieties, starting late June or early July) or when you first detect squash vine borer adults. Keep the barriers in place for about two weeks after the first adult borer has been seen. Be sure the row covers are securely anchored to prevent adults from moving underneath it.



Caution: Generally do not use floating row covers anytime crops are flowering. This prevents bees from pollinating your vegetables which will have a negative impact on plants. An exception to this would be if you pollinate your crops by hand while the floating row cover is erected.


(I'm replanting the cucumbers and squash this week & hope for success !)