I first noticed it as my Bayse's Purple leaves turned purple and started to die back, an otherwise healthy rose. Other roses are starting to show damaged branches including non rugosa types. Below is a link. Seems the only thing to do is cut out the branches and burn or throw them out - then seal with elmers glue or vaseline (which I find becomes a little gross). I might have to cut Bayse's almost all the way down. Fortunately, it has put up some new canes and I started a new plant in the spring. Just thought I would give you all a heads up just in case.

Here is a link that might be useful: Pictures of stem girdler @ invasive.org