Red Oak Galls?

[ChampionTree]

Can someone please inform me on what is causing this on a Red Oak. Iv never seen it so bad. Tree is roughly 10 in in diameter.

 

[mrtree]

No big deal, cannot tell you the exact species but tree is reacting to the ovipositing of eggs by insects such as gall wasps. The eggs have been laid and there is nothing you can do.

Oaks are one of the host trees with the largest range of insects making use of it. Galls on oaks are so common that Audubon even painted galls on the leaves and twigs of oaks his some of his subject birds were perched on.

 

[ChampionTree]

I figured as much, would you recommend a mild insecticide prior to bud break in following years? The owners of the tree think this is something catastrophic. I told them otherwise, but they are peace of mind type of people. Also, I'm not sure if the two are related, but would high nitrogen attract or be a catalyst for the wasps? I am just trying to find a decent control and possibly over fertilizing the area is contributing to excessive insects. It's a bit of a long shot, but I would like to see less "damage" in future years.

 

[mrtree]

I am not sure that ovipositing is related to nitrogen levels in leaves in the way that feeding is.

As for insecticides, I would not, the galls are not really hurting the plant. Pesticide application may be useful to your wallet but not to the tree.

Also remember that there are lots of insects using the oak that are harmless or even beneficial and you do not want to kill these.

 

[ChampionTree]

I appreciate your input. I will relay the message. I will just help them come to grips on the reality that nature is in control.

 

[mrtree]

Part of any IPM and PHC program is setting thresholds. In this case I am not sure, other than visual appearance, that the galls are doing any harm. If you cannot identify, and to a large extent quantify, the harm you should not be treating.

 

[guymayor]

Excess nitrogen might be a factor. It stimulates excessive growth, in terms of size of the galls, and maybe the number of them.

 

[guymayor]

Excess nitrogen might be a factor. It stimulates excessive growth, in terms of size of the galls, and maybe the number of them.