Here in the PNW we have two types of cane borers--rose cane borers and raspberry cane borers. Rose cane borers are mostly annoying. They kill the top inch or two of the rose cane but new growth will emerge further down the cane and the rose will be fine. Some people will seal the cane but those of us who have lots of roses don't bother--it takes too much time! Raspberry cane borers are a differant matter. They will burrrow all the way down the cane and even into the crown of the plant and maybe kill the rose. Since you say your rose was killed I'm guessing that this is what you have. The good news is that roses are not the prefered food of raspberry cane borers--they prefer raspberries and if they can't get them they go for blackberries. If you have them on your roses it is usually a sign that somewhere in your neighborhood someone has taken out their raspberries or taken out blackberries and the hungry critters ate your roses. After a few years the cane borers will either die out or the raspberries or blackberries will come back and they will go eat those. In the meantime, you can control the borers by keeping an eye on your roses and if you see dieback on the canes below two inches, cut back the cane to below the dieback. You will see a catapillar-ish looking thing at the bottom of the tunnel. Dispose of it. The good news is that since these critters have a one year life cycle, once you have disposed of them, they will not come back for a year. I don't know if a systemic insecticide will work. Systemics cannot be used on edibles and since this is mainly a pest of raspberries, the insecticides will not be labeled for use on raspberry cane borers. But they might work for raspberry cane borers on roses. But it is probably less work to just cut them out when you see them rather than spraying.

hello Michael: The Ceratina Bee females WILL continue to tunnel into the plant to accommodate multiple rearing cells. They don't stop at just one cell. The general range is two to twelve cells, although many more than that have been observed. At a minimum size of 3 cm. per cell, twelve cells means the females will have excavated well over a foot into the plant. I'm not saying they will go that deep all the time on every rose they nest in, but as you have already discovered, they may certainly go more than just an inch or so down the cane. Please check out the article I provided and the references there. I'm glad that you don't see much Ceratina bee nesting where you are. Baldo lives in California where these bees are also apparently uncommon. However, Ceratina Bees are quite common around here, and they will nest in rose canes if one doesn't seal the cuts. To speak generally, if you don't get the bees where you are, you don't have to seal the cuts. If they are present in your area, it's a very easy preventative. Actually, garden roses aren't even their preferred nesting plants. They much prefer native species - roses and otherwise. So it doesn't take much to convince them to move on and look for better sites elsewhere.- just a blob of glue that disappears in a short time. And Susan - No these aren't leafcutter bees. In fact, they are so tiny that you might not even recognize them as bees at all. To the naked eye. they do look more like gnats They are considered beneficial pollinators, however, which is why I don't recommend insecticides. This post was edited by nickl on Sat, Aug 17, 13 at 13:19

Hi, Brandon. Thank you for writing from my region! I have also grown roses here since the mid 1990s, and I've never had rose borer problems either until recently. I checked my neighbors' roses today and notice that many also have borers. The buggers seem to have moved in during the last couple of years or so. I can identify old holes from (at least) last year in my rose canes. Things have been rather hectic at my house, so I haven't been paying a lot of attention to my garden over the last two years. This year, the critters seem to be legion! They even bored through the Elmer's Glue and nail polish I just pasted on my Penelope. I really should prune my OGRs after bloom, anyway, so I think that's what I'll start doing. Due to time constraints, I've always pruned all my roses except ramblers in late winter. If my HTs and floribundas survive this spring, I'll seal them with something more durable each year and do what you suggest, prune them a little later in the springtime. Do you know when rose borers are done with the egg laying stage? I'm researching that topic. I'll be curious to hear if my neighborhood is an anomaly or if rose borers are becoming more plentiful in the Willamette Valley. Raspberries have grown in popularity in my area, so I'm checking out raspberry borer sites as well. Thank you again for your local feedback and any new info you discover. Carol

The problem is that there are many bees and wasps that will use canes as homes for their babies. Plus there are other insects as well i.e. raspberry cane borers and others. It is not that bad for me since my winters tend to kill the canes anyway. There are more than 500 species of carpenter bees. So more than likely mine guys would not be the same as yours. In most cases the bee does not enter the canes as far as I know. It drills into the cane places a lump of food for the kids. Then deposits her eggs and seals the hole up. They love to use my phlox. At the beginning of October which is early for many. I cut them back then have to cut diagonally into cane till I find the bores. These are mostly the white wormlike ones. It is a pain for sure but it has to be killed or there will be even more of them. If I wait to long these types will enter the crown and eat all winter. My point is it would be all most impossible for us to find your culprit and you won't find the actual bee etc. in the cane. I have found them before by watching mommy bee continuing to return to the same plant. So I got up by the plant sat down on the ground and watched her work. That was interesting.