Trees, Shrubs and Conifers: Any ideas on problem with my Chitalpa? , 1 by cactuspatch

cactuspatch wrote:
I have 2 trees. One is beautiful and the other is looking sad. They were planted at the same time about 40 feet apart, 5 years ago. I thought it was maybe that this one was not getting as much water as the second one is near to my fence and possibly can get water from the grass inside the fence. Today I went to look closer and found several small light grey insects scurrying around the leaves--what are left of the leaves. There are many new leaves coming on.
I don't know how to search for insects as the bug files seem to be organized where one would need to know a name? I tried to get a photo and the bugs are too fast and hide from the camera when I get it close enough to snap a shot.