When I see ants on the branches of my apple tree I know to go looking for blackfly. Question. Do they bring them to the tree from elsewhere or do they just re-arrange ones that are already on the tree? Can the blackfly flourish without the attention of the ants?
If it is that they bring them to the tree then I could maybe stop the ants from climbing the tree with a grease band or something sticky. However if the blackfly are already on the tree and just grouped by the ants stopping the ants would be a bad thing as I would never find the blackfly without them