This may be the oddest post yet to the problem of ants farming aphids on fruit trees. Has anyone ever considered sticky fly strips? The idea randomly popped into my head when I was taking stock of our insect-control stash. One strippy thing left. Hmm... Google turned up zero results on anyone trying this method, but the logic is that nobody ever likes stepping on gum, or anything that'll stick to the soles of their feet, so why not apply that to ants?
So far what few that have tried to go up are stopped in their tracks, and those that wanted to come down are caught at a dead end. The one or two that managed to crawl under and escape (the tape is a dual-sided sticker) were either trapped in the middle or caught at the second road block. The good thing about this is that I'm not using chemical sprays, and the tape is pretty effective as long as it doesn't rain. I'm not an expert on insects but it also makes sense that I only have to use the strips during the period in which ants are most likely to farm the aphids (spring/summer). If I can thwart them, and give the tree and potential peaches a chance, that's a better outlook on harvesting fruit, right? We have one each of peach, plum, persimmon, pear and cherry, so it isn't impractical to tape them all.
The one downside is if ladybugs get stuck, but up here at this altitude we don't see much of them around. The bees I'm not worrying about because all they want to do is buzz about and get drunk on the flowers. This morning I checked the trees and the only ants visible are caught on tape.
Average daytime temperature: 19°C / 66°F