I am located in N Calif and have more that 75 Rhodes. Many of the plants are infected by some kind of pest. A new shoot will wilt and when I break it off there is a small whitish worm, about 1/8 inch long, inside. I have not found anyone who knows what this is or how to control. I do have some weevil damage on the leaf edges. However, the symptoms discribed here don't seem to match those for the weevil larve. Any ideas?
Sounds like Synanthedon rhododendri but thought that was just an eastern problem. There are other bores that will attack rhodies -- it is a borer. http://www.umassgreeninfo.org/fact_sheets/wood_attackers/rhododendron_borer.html
Possibly new to the area. Take samples to nearest Extension office, where they can tell you what it is, as well as make a note of it in case it is new there.
