I have lots of maples leafing out in the hot(!), early spring in England. One has been up in the sun for a few days (in a pot) and was doing fine. Today, I've noticed most of it's leaves are either wilting or dying rapidly. It does not look well at all. It's a relatively young plant. I would like to know if anyone can identify what is wrong and if there is anything I could try. I have many other maples nearby, all seem in excellent shape and I would hate this problem to spread to the others. The symptoms are rapidly wilting and dying leaves (approx. 1/2 the leaves on the plant) with sometimes a whitish powder at the base of the leaves and in one small area on the trunk - possibly fungal. This tree has changed dramatically in the last 24-48 hours, and looked healthy then. There are some aphids on it, but not enough to cause this rapid change. I have attached some photos - sorry about the quality, it is getting dark here.