You said "I've already removed a handful of particularly badly affected leaf clusters, but I'm concerned I'll shock or damage the tree and affect ripening."

How old is the tree? I ask because a big old tree won't ever notice whereas a young tree might be.

Beyond that, a harsh water spray can knock aphids off, possibly a few cherries too. Repeat as needed.

If the tree is young and/or small, simply squish the leaves -- just enough to kill the soft-bodied aphids.

I would spray summer oil on aphids. I find it is very effective for me and there are many kinds of summer oil that are completely non-toxic. Even if you don't treat them you will probably be OK, eventually the predators will show up for a feast.

Scott

The tree is at least ten years old and possibly older. It is a quite a hearty thing. As for the predators, I already see ants carrying off supper. I think I will continue surveillance and pinpoint leaf-removal, as I doubt the aphids will win the two-week battle against me during harvest. Then I'll spray the whole thing and hopefully avoid a repeat next year.

Many thanks.

Michael,

The ants aren't carrying off supper. Ants and aphids work together, the aphids drink the plant juice, and the ants carry them around. Ants are rewarded with the aphids honeydew. It's been my experience predators won't touch the aphids while the ants are there to protect them. Get rid of the ants by putting some barrier on the trunk (burlap coated with tanglefoot) and you should get rid of your aphids.

Wow, good one, thank you. I'll do the burlap and pinch leaves too.