Thanks, Jeri - that's good to know.

To me it looks like flat head apple borer damage. I think Kim pointed to that issue when I had a branch like that here. The plant was alright, but I had to trim the afflicted cane off.

Thanks Sheila -- That's something I've never seen here, so I am glad for the education.

With increased heat and decreased rainfall, I imagine that plants of any kind are weakened and diseases can more easily take a hold. I read that the forests of Oregon and Washington are experiencing increased dieoff and other problems because of this. Unfortunately, that also increases the speed and ferocity of wildfires when everything is tinder dry.

Sheila, I had a close look at the affected areas this morning, and can see no holes or dust. Do you think I should see holes, at least?

I did a dissection on mine and there was brown powder under the bark. I didn't know what to think when I first saw it, because it was so ugly! I think Kim told me about this problem.

Here are a couple more.

The plant is fine 2 years after surgery removing this horror.

Thanks for the photos, Sheila. It certainly looks similar. I'll check again, lift more bark. We had rain yesterday, so that may have washed any powder away. The growth is fine on that branch. Did you notice a decrease in growth? Also the branch comprises around two thirds of the plant, so I don't want to cut it away unless I have to. Also, did you see any holes when you cut it?

I only saw the powder after I did the "autopsy" and cut under the bark. In my plant, the peripheral growth on that branch started to wilt, so it needed to be cut off. I then did root the peripheral cane after cutting off the afflicted segment. I don't know that I really saw the borer hole. Kim explained they attack sunburned canes which this plant had. I'll try to find that thread, Trish.

Trish, search for my "Triple Threat" in Antique Roses and you can see what Kim thought.

Thanks, Sheila. I'll do that. I'm pretty sure my rose suffered sunburn, so it certainly seems possible that it's borers.