Mountain Ash Tree Leaves Have Been Eaten And Left With Just Their Veins

Question From: Surrey, British Columbia, Canada
Q: I have two lovely mountain ash trees about 6 years old. They have grown beautifully, but I noticed about 10 days ago that there was a problem with the leaves. I realised that something was eating many of the leaves ( both trees-about 30feet apart) were being eaten, just leaving the veins of the leaf intact - do you know a reason for this - what can I do?? Many thanks.

A: Your tree's leaves are being eaten by some kind of larvae or bug. Take sample to your local independent garden center for an ID so you can select the best product to use. They may have done their damage and left to pupate to adulthood. If so, they may be back. But spraying now may be a waste of time. Best Nancy