Rose worms leave that lacy look in my garden. They are sawfly larvae, not caterpillars so Bt doesn’t work on them. Squishing works, or knocking into soapy water or I think insecticidal soap. You could look up to see if something like summer oil might work.

Thanks, NHBabs. I looked for the FAQuestions link, but couldn't find it so posted this query. I take it that it's not a "fatal" conditions because we did have sawfly larvae on pines several years ago. We inspected all the pines for sawflies ... but didn't know about their loving roses, too.

It most likely isn’t the same species of sawfly as was on the pines, but I regularly get them on what I think is New Dawn rose and it hasn’t noticeably slowed down the rose which is quite vigorous.

Yes, you're right. These are much skinnier and greenish. Those on our pines were bigger. Ugly critters. I hope Dick comes back with vigor. I really do need to clean up the area around hi, though. Also need to put some monarda, etc., nearby.