If you see ant, you prolly have aphids. Otherwise a caterpillar might be doinng the damage. I doubt its a cuke btl.

Could it be pear slug? I saw the first ones on one of my quince yesterday. The tree is small enough I squished them with my fingers that just happened to be gloved at the time.

They are a form of sawfly and apparently very fragile and, in spite of their name, pretty indiscriminate about what species they'll eat.

Here is a link that might be useful: pear slug damage?

Thanks. I think it could be aphids eating the new growth of the Hosui because of the way the new growth is dissapearing. The freckled holes(not see thru but brown on both sides of the leaf) on my multigraft seem like something bigger. It's not slugs on either. I would see those for sure.

Aphids are sucking insects. There's a caterpillar somewhere.

Thanks. Going caterpillar hunting.