I attended the Minneapolis Home and Garden show last week, and after viewing the gardens and checking out all the cool gadgets, I stopped in the MSHS room to buy a few lily bulbs. While there I visited with a young woman from the Minnesota Department of Agriculture who was handing out information on the Emerald Ash Borer, which has been discovered in two places in Minnesota. While there are several signs of the borer’s presence, what’s the first thing most people see? Woodpecker holes. Apparently ash borer larvae are woodpecker candy, so if you see an ash tree that’s getting a real going over by woodpeckers, you may want to look further.
Other signs of an infestation include die-back at the top of a tree, especially if several ash are planted together and they all look bad; D-shaped exit holes in bark; and sprouts of leaves and branches from the base of the tree.
Of course, the first thing to do when scouting for Emerald Ash Borer is to make sure you are looking at an ash tree. I put this guide up a couple of years ago, which might be helpful in determining if the tree you have is indeed an ash.