Hybrid tea Roses have white waxy caccoon looking growths on several plants in new mexico (*zone 7). Never had this problem in 10 years until now and started late summer. Seem to be killing stems/leaves on three plants. Simular in size to spittle nests but not bubbles, more the consistancy of ear wax. What are they, how to control, and concern about spreading to other roses, that is will they kill. Will get pictures. here is pic -- cacoons on right more focused then cacoons on left. I really don't know roses and so can't help this person -- any help would be apreaciated!
In the many years I have been growing roses, I have never seen anything like this in our area. If it won't destroy the plant, I would prune the affected area away and get rid of it as quickly as possible. You may also wish to check with a local Rose Society to see if someone can give you better advise.
I've looked through my pretty comprehensive plant ailments literature and I can't find anything that matches. I hope someone can help. Not least to treat your plants, but also because I would like to know what this is myself!