Squash Vine Borer - Amy Stone and Curtis Young


Squash Vine Borer Adults, Photo Credit: Margie Black

Everyday in Extension, questions come in through our offices via telephone calls, emails, samples and/or photos. Ohioans seeking information turn to Extension as a source of research based information on a variety of topics. Here are some questions that BYGL writers commonly field across the state: 

  • What is this plant?
  • What are these insects?
  • What is happening in my garden? 
  • Should I be concerned about this damage on my tree?
  • Why is the turfgrass turning brown?
  • Should I test my soil? 

The list of questions can go on and on. We are grateful that Ohioans are "Leaning on Their Land Grant" and seeking the answers from an unbaised source who wants to empower and engage residents through these educational opportunities. 

While some questions can be answered and information provided at the local level, some questions require additional input from others with a certain speciality recognized across the state, or the assistance of OSU's Plant and Pest Diagnostic Clinic (PPDC). It is important to understand that some questions, might not have a clear-cut answer, or could have several possible answers. And some times, the answer isn't what the clientele may want to hear. 

Yesterday, I received a couple photos from a client and friend who observed and was able to capture some images of a couple insects in her perennial garden. The insects where just hanging out. While the photos were IDed by Curtis Young, I began to wonder if one resident was curious to know what the insects were, could there be others searching out the same information. Or if sharing the information via BYGL might just arm Ohioans with information and they will recognize the insect the next time they see it in the landscape or more importantly in their vegetable garden where this insect is a pest. 

So what is it you ask? 

Squash Vine Borer AdultsPhoto Credit, Margie Black 

The insects captured in the photos above are adult stage of the squash vine borer (Melittia satyriniformis). This insect is a significant pest of squash and pumpkins, but can be problematic to cucurbits and melons as well. 

The insect overwinters as a pupa, typically emerging as adults in mid-to-late June. The black and orange to red moths will lay eggs throughout July and August. The eggs are oviposited individually or in small groups on the stem of the host plant just above the ground surface. The eggs can take up to a week to 10 days to hatch. After hatching, the larvae enter the stem of the host plant, leaving a small hole surrounded by frass - a telltale sign. The larvae will feed while tunneling through the plant stems for about one month. This injury will cause wilting or sudden collapse of the leaves where the feeding occurs. Once the feeding is complete and they are ready to pupate, the larvae will burrow into the soil and spin a cocoon. They will remain in the soil until the following June. 

It seems once you have experienced the not so joyful encounter with SVB, the field or garden may be more likely to have problems in the future. When infestations are identified early and damage is minimal, plants can recover by carefully removing the larvae. I have friend and colleague who has become an expert at carefully cutting the stem, removing the insect, and doing a squash vine borer squish - whew! She had plenty of experience as she worked with community gardeners in gardens across Toledo earlier in her career, and now in her own garden.

For additional information about the "insect-extraction" process, and additional cultural controls to add to your management tool box, check out the Squash Vine Borer FactSheet from Penn State University below. It was a great surprise to see a photo taken by Jim Jasinski with OSU as part of their FactSheet. Go buckeyes!  

Let is know if you are seeing adult SVB activity, or have faced the challenge of this pest in your garden or field. Hopefully the timing of this alert you make you more alert to this boring insect.