This year I found some extensive damage in my garden. Leave are dropping, looks like they were chewed on at leaf stems and just dropped after. It is on a wide variety of plants in multiple locations. On the maple, I can see some ants walking up the stems, but I would think this is too early for aphids? It effected my lace leaf maple, hardy impatiens, hydrangeas, astilbe and more. I have attached some photos, can someone give me some idea what I am dealing with here?
I suspect cutworms are climbing into various plants at night and randomly chomping on them. Sorry, I can't help with identification or treatment. If you were up to it, you might go out after dark with a flashlight to see if you can find any of the culprits and deal with them appropriately. You might find more information on Dr. Linda Gilkesson's website: Linda Gilkeson | West Coast Gardening | West Coast Gardening: Natural Insect, Weed and Disease Control