Can someone please identify these strange growths on my Plum tree leaves. My tree leaves are infested with this and I think it is killing my tree. I've attached 3 photos. The trees are probably at least 20 years old. We have owned the property 10 years and they were mature when we moved in. We have two trees and they both have this problem, they are right next to each other. The "cottony" stuff you see in the pictures is just cotton from our Cottonwood trees.
Run for your life!!! Ye gods! Pretty scary looking. Take a look at this: http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=16235 And: Welcome to the Forum!
I'm no expert but they remind me of inchworms, or whatever those little green crawlies are called. I found one on my spearmint today, plucked it off. Maybe they're cocooned little guys? That may also explain what looks like webbing I see.
Those are leaf galls. Leaf gall mites snack on the leaves and what you see are the growths the leaves make to try to heal the area. They are ugly buy typically harmless to a tree. I've been told they are self-limiting, since the mites attract their own predators, but my trees have had them for several years running.
