Over the last 2 years I've had a lot of problems with vine boring worms in my squash plants, the larvae of some fly or something from what I've researched. We like to make zucchini cake, so I plant a lot of plants. The last two seasons I've lost every plant to these stupid things. The plants grow huge and get lots of blossoms, maybe start producing, and then in a matter of days they're laying dead on the ground. The stems have a hole in them at the soil level and it's like mush in that area. Cut them open and sure enough, there's the worm. I've tried using 7-dust and I've tried using a syringe to inject the stems. Anyone have a way to get rid of these things? Are they in the soil over the winter?
I know this post is older but wasn`t sure if you ever found the culprit. And I am not positive but could be squash bugs, they do the same thing and it may be the larvae you are seeing. As with many of these,, borers or squash bugs, you have to treat before they hit. By the time you notice it, its already too late. I treated my soil with Ortho Max a couple of years ago and will do it again this year for underground bugs and I always use the sevin dust or permethrin or pyrethrin spray regularly on the plants themselves from the time they are planted and do it weekly.
Sorry I didn't see this sooner, but keeping them covered with row cover until they are in blossom seems to help here.. That allows the stem to harden to the point of being more resistant to the borer.
