Hi Amy,

Oh no , another destructive devil. I just spent a couple hours this morning trying to cut out borers from my squash.

https://www.cropquest.com/controlling-sunflower-borer/

There isn't a great solution. You have to examine the remaining plants regularly to catch them before it's too late. I would experiment with "sleeves" on the stems next year. Try too create a physical barrier so they can't get  lay their eggs. Since you know they will be back.

There may be some trap ....I would google around and see what others may have found helpful.

Sally Granath

St. Louis County MG