I love Cherries and the trees are beautiful this time of year. Ours unfortunately, gets smothered in Blackfly very soon. Happens every year and I don't know/can't find out how to treat it effectively. And BTW ....... every part of a Cherry tree and its fruit is poisonous to dogs. Nothing to worry about this time of year though and tbh Mrs Biscuit mithers far more about it killing our 5 than I do. I would guess they'd need to ingest quite a bit before it gets serious? (except for the fruit pits of course).
We have trouble with Black Fly all over an Elderberry Tree we have. We can't get to all of it, and don't want to use nasty chemicals, but find we can keep the bits we can get to clear by spraying a weak solution of water with washing up liquid on them with a small handheld plant spray gun. Apparently the soap breaks down a coating they have and stops them breading.
Security Was it near a ferry port? Maybe showing the boot hadn't been opened since checked. Or When visiting a contract manufacturing supplier in Hungary many years ago that also made millions of mobile phones they sealed our bags with something similar to an event wristband to show we couldn't have slipped a mobile in there whilst nobody was watching. They also security tagged our own phones and Laptops to show we'd taken them in.
I just did a google search on aphids / Black fly & Cherry trees... I didn't know ants played a role... Preventive Action (Ant Management): Ants transport aphids and protect them from predators. Apply grease bands or a physical barrier (like Vaseline) around the trunk in early spring to stop ants from reaching the canopy.
