feelie75
Newly Registered
Posts: 2
Joined: Tue Jul 06, 2010 3:20 am
Location: Oregon

Red bulbous blisters on tree leaves. Disease??

So I was just walking past the mystery tree that sprung up last year. Thought it was a weed, cut it back a ton last summer until I finally looked up the leaf and found that it might be some sort of Willow.

ANYhow, I thought I saw fruit on it! Little berries. But then I looked closer and saw that almost all of the leaves had red blister-like things all over the leaves.

I've taken a picture here:

[img]https://i23.photobucket.com/albums/b388/feelie75/Misc2/leaf_red_bumps_IMG00022-20100705-20.jpg?t=1278386318[/img]

Anyone know if that is some sort of Leaf Disease??? What can I do to cure it? And is it some type of Willow? I think two trees might be growing in the same spot; you'll notice long skinny leaves in the picture as well.

Thanks for any help!![/img]

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Kisal
Mod Emeritus
Posts: 7648
Joined: Tue Jun 24, 2008 5:04 am
Location: Oregon

Welcome to the forum! It's nice to have you with us! I'm always happy to see another Oregonian come on board. :D

Those are leaf galls caused by an insect, possibly the Willow Redgall Sawfly, Pontania proxima, although there are others.

Unless a tree is a small sapling, or diseased and unhealthy, gall insects don't normally cause any damage. They're just somewhat unsightly.

If your tree is small enough and has few galls, you can just remove the infected leaves. It's usually recommended that very heavily infected plants be destroyed, but I suggest you contact your nearest Extension Service office and check with them before you do that. The phone number should be under the county listings in the White Pages. :)
"Isn't it enough to see that a garden is beautiful without having to believe that there are fairies at the bottom of it too?" - Douglas Adams

feelie75
Newly Registered
Posts: 2
Joined: Tue Jul 06, 2010 3:20 am
Location: Oregon

Ah, thanks for the information, Kisal! :) Hmm, yeah I don't recall seeing a lot of insects on it, but I don't really pay that much attention to it that closely I guess.

I'll keep an eye on it and see how it's doing. I did notice after I posted that the side of the tree facing the house is pretty un-touched by the blemishes. It was mostly just the sidewalk-side I looked at that had them.

The tree is quite tall now. From about 4-foot last summer, it's probably about 20-feet in height now so hopefully it'll survive fine.

I'll do some research on the bug and see if I can detect evidence of them around the tree.

Thanks again!

yay oregon! ;)


Kisal wrote:Welcome to the forum! It's nice to have you with us! I'm always happy to see another Oregonian come on board. :D

Those are leaf galls caused by an insect, possibly the Willow Redgall Sawfly, Pontania proxima, although there are others.

Unless a tree is a small sapling, or diseased and unhealthy, gall insects don't normally cause any damage. They're just somewhat unsightly.

If your tree is small enough and has few galls, you can just remove the infected leaves. It's usually recommended that very heavily infected plants be destroyed, but I suggest you contact your nearest Extension Service office and check with them before you do that. The phone number should be under the county listings in the White Pages. :)

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