What is happening to my sunburst locust tree?
I live in Toronto Ontario, Canada (zone 5a-5b) and 8 years ago, I planted a 7 year old sunburst locust tree. It has done very well over the years, doubling in truck width and standing close to 20 feet tall. In the past few years, every spring, aphids (I think) would lay eggs on some of the new growth making the leaves curl back on themselves and form a small seed-like cocoon. It didn't damage the rest of the tree but just looked ugly so I would cut off the affected areas and everything went back to normal (even got a second growth about mid-summer). This year it's different - VERY different. A third of the new growth didn't develop and all the compound leaves fell of the main stem, leaving the branches with these little clumps of needle-like stems. I have no idea why. We did not do anything different this year to our garden (we don't even spray pesticides)so I am very puzzled. I have noticed that on my street, the white birch trees have slowly been destroyed (I'm thinking leaf miners) and had to be cut down. Could this be the same problem? What concerns me is that this is a very nice tree and I would hate to have it cut down. Moreover, I have a wonderful white birch not 15 feet away (no signs of disease or pests on it!) and I would hate it to spread to that tree as well. Can anybody help me find out what's happending? Thanks