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Squash vine borers are out now

Jeffrey Hahn, Extension Entomologist

Are you growing squash, pumpkins, cucumbers, or melons in your garden this year? If so, now is a great time to start monitoring for squash vine borers. In fact a gardener in Minneapolis has already spotted several adults flying around his plants. Squash vine borers are a potentially devastating pest as the larvae bore into the stems, causing plants to wilt and eventually die. The best management is well timed insecticide treatments when adults are active and laying eggs.
Are squash vine borer moths in your garden now?  Check now
so you can take action when they first show up.
Photo: Jeff Hahn, UMN Extension

Adult squash vine borers are day time flying moths that resemble wasps. 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 may not always be seen plainly) is clear. There are a couple of methods for detecting them in your garden - watch for them flying around while you are in your garden and/or 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 will fall in. It is then an easy matter to check the container for their presence.

As soon as you spot one squash vine borer, start treatment. There are a variety of insecticides that can be applied. If you don’t see any but have a history of these pests in your garden, begin treatment by late June or early July (the further north you are located, the later the moths will emerge).

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

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