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Be on alert for squash vine borers

Jeffrey Hahn, Extension Entomologist

Male and female squash vine borers on a date.  But make no
mistake, they are looking for your garden when they're done. 
Photo: Jeff Hahn, University of Minnesota Extension
If you are growing squash or pumpkins in your garden be on the watch for squash vine borers. They are beginning to emerge and may be in your garden soon!

How to identify, detect a squash borer

Adult squash vine borers are wasp-like moths that are active during the day. They are about 1/2 inch long with an orange abdomen with black dots. The first pair of wings is an iridescent green while the back pair of wings, which is sometimes hidden, is clear.

There are a couple of methods for detecting them. Watch for them flying around while you are in your garden; they are conspicuous and easily noticed.

You can also place yellow containers (like pans or pails) half filled with soapy water. These moths are attracted to yellow; when they fly to the container, they fall in to the water. Then just check the container for moths.

How to manage this pest

As soon as you spot one squash vine borer, start management. If you don’t see any but have a history of these pests in your garden, take action by late June or early July (the further north you are located, the later the moths will emerge).

The larvae are a serious problem; they cause wilting and eventually death to plants. You can exclude the adults from laying eggs by using a floating row cover. There are also a variety of insecticides that you can apply, such as permethrin or carbaryl, to help discourage them.

For more information, including management, see Squash vine borer management in home gardens.

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