It certainly sounds like galls but we can't tell you what kind without a picture. There are many species that affect ash.

Why was the tree treated with imidicloprid? This is a terribly over-used treatment anymore and it really bothered me when its appearance has been introduced to OTC products. Yes, it works great but won't someday soon because it's just everywhere and being used on everything.

As to galls........if it is a gall. They are a physiological response from the tree in response to various insects and of themselves are not harmful.

in other words.. all leaf bumps ... well maybe not all ..

ARE COSMETIC ....

and since its a deciduous tree.. they will be gone in fall ...

its one of those plagues.. that come and go .. over the decades ....

the systemic was probably a brave attempt to thwart EAB .... and i decided.. long ago .... the ash wasnt worth the cost in MI ... you ought to talk with your extension office.. and find out what the odds of long term success are in your county ...

consider the bumps an 'extra' show of mother nature ... relish it for it oddity.. rather than worry about the tree ...

when you get down to it.. i have seen trees basically made leafless by hailstorms.. and they never look back.. so your little bit of cosmetic leaf damage is nothing ... because the leaf is still intact.. and functioning ...

go zen on this type of stuff.. ooohhhmmmmmm

ken

OK, if it's just cosmetic, I don't care.

Yes, the treatment is for EAB. The tree has no borer infestation, but just in case... It was recommended by the extension office because I'm in a EAB area.

Paul

I hope it works for you, Paul. Our area was just included though I had a hunch it's been here awhile already. I can find no hard evidence it's effective, but then again this is a newbie pest and it would be hard to come by long-term data.

What are these green bumps on the leaf, please? Are they harmful to the tree (ash?)? if so, how can they be controlled?

Thanks, Ken