Why those river birch leafs look like that?

[misuszatek]

Professional company delivered and installed 12' river birch I picked few weeks ago.

I noticed some leafs are chewed on. My suspicion is larvae of the Dusky Birch Sawfly but I'm not arborist. 

Is that something serious? should I do anything or the problem will go away?

 

Thank you for any advice.

Edited May 28, 2021 by misuszatek

[BonzerBob]

There's been a lot of alder beetle around this spring and the sawfly larvae are pretty easy to spot.

 

Having said that I can't see any alder beetle in your picture either, but they do move on.

[misuszatek]

31 minutes ago, BonzerBob said:

There's been a lot of alder beetle around this spring and the sawfly larvae are pretty easy to spot.

Having said that I can't see any alder beetle in your picture either, but they do move on.

Yeah, couldn't spot anything either when inspecting the tree. As I wrote..I picked the tree weeks ago and was just brought yesterday so I assume they had something on their farm that ws eating those leafs.