Interesting! I had borers for the first time this year (the garden is 10 years old) in my queen-of-the-prairie and nearby sweet black-eyed susan. Not devastating, but a nuisance. The droopy plant-tops signaled the problem and I killed all the several borers I found. These insect things tend to be cyclical or occasional. In the case of the borer, the reasonable thing would be to remove/burn the plant material this fall or in early spring as a precaution.

Strange. Could be what I'm experiencing also. Otherwise healthy meadow blazing star turned limp and wilted over the past 3 days. Weather conditions, etc. aren't related since we've had good moisture and sunshine recently.

Starting to look like a Wisconsin/upper midwest phenomenon. My first clue was wilted over plant tops with heat and drought not an issue. Rod, try cutting the stem well below the limp part and examine its length for a small hole possible exuding some dusty "matter." I found stems to be eaten out hollow on the inside with a tiny grub doing its business.

johnp, I think you're right about being more of a nuisance than anything else.While individual stalks were infested, the rest of the plant was healthy. I think most borers overwinter in the nearby soil, so hopefully by removing this year's grubs there will be less next year.

I have borers in many types of plants. I am wondering if Bt would work on these and when to spray since they are inside the plant. Most were striped "worms" but the ones in my lilies looked different. I consider it a serious problem in my yard. The lilies were the greatest loss.