We have a mature cherry tree in our backyard in Victoria. I'm not sure of the type since we didn't plant it, but it produces small, sweet red cherries. We were able to harvest a reasonable amount of fruit the the first couple of years we lived here, but the past couple of years, the cherries have withered and turned brown just as they were starting to set. The leaves are full of holes and there are tiny ants all over the tree (although I don't see any signs of aphids). Thinking that it must be a caterpillar, I sprayed the tree with BTK last year, but with no noticeable improvement. I am attaching photos - can anyone help??? Thanks so much!