What’s eating my birch trees? 🌳

[Treesplease]

Help! What’s eating my birch trees?

I have two himalayan birch and one silver birch.

One himalayan birch is completely fine and looking really healthy.

The other himalayan birch is looking very limp and the branches have died in a straight line up the tree, so the tree has now bent over.

The silver birch was absolutely fine last year, but this year is more straggly, has some very bare looking branches, and the leaves have been eaten by something.

There are no visible pests on any of the trees.

Help please, oh great and wonderful gardening people.

(first 3 photos are the silver birch, last photo is the droopy Himalayan birch)

Sorry but your photos are rather blurry and distant! Can you do a close up of where the branches have broken off, and another of the nibbled leaves - with the sun behind you so they're not backlit?

I would support the one bending over with a stake.

I think caterpillars are eating your tree leaves. Agree you need a larger stake for your tree, that should stop it listing. New trees need lots of water, for much longer than you think, so that would help too.

Birch's like feeding too. They also prefer not too much grass around the trunk.

Thank you! Adding some more photos.

The grass is cleared around the trunks. They have been in for two years, were well staked and were very well watered with tree bags through the first year.

On the himalayan:

You are right, it’s caterpillars! But they are so so so tiny. I went out and inspected it with my glasses on and took the photos, and it was only when I zoomed right in on a photo of the leaf that I could see the caterpillars (the photo with the holey leaf).

I don’t think it’s the stake causing the problem on the one that is leaning. All the branches on one side died, and it is leaning towards the side that still has the branches - I assume because it is heavier on one side.

Would it be the caterpillars that caused the branches to die?

There is a 2nd himalayan right next to it, and it is perfectly healthy.

On the silver birch, I can’t see any caterpillars even in close up, it just has quite a lot of bare branches