So, I got a load of firewood this winter and as I was helping the guy unload it from his truck, he pointed out some emerald ash borer markings –
Emerald ash borer larvae go through four instars before leaving the tree as an adult. In the photos, you can see different sized trails and the largest ones exit via a hole, the famous D-shaped hole that is about the only external evidence of infestation before a tree dies.
Now, it would have been nice if he told me about this before he brought it over, but I guess it doesn’t matter anymore. Most of the ash trees in northeast Indiana are dead. Anywhere you walk in the woods it is very easy to spot them. They still have the bark on, but it looks patchy and dying. They’ve looked that way for the last two years. It’s not like when an elm tree dies, presumably from Dutch elm disease. In that case, the woodpeckers peck the bark to pieces to get the yummy invertebrates underneath the bark and within a season the tree has no bark. Apparently emerald ash borer larvae aren’t so yummy, so the bark stays on. I suppose in a couple of years the bark will slough off and the woods will be full of tree skeletons. Of course the tree skeletons will provide homes for many critters and eventually all of the energy that went into making that tree will be released for any number of reasons.
A forester friend of mine told me that some ash trees in China, where the emerald ash borer came from, have a resistance to it. He suspects that there may be a few North American trees with this property, and of course they will be the ones that will survive and reproduce and that in the long run the ash trees will come back. However, this will take hundreds of years.
The cycles of life take many fascinating twists and turns!