Thin Crowns on Maple this fall

We've fielded several questions about this from folks in upstate NY and Vermont. There is an interesting segment on thin maple crowns in Vermont this fall. https://fpr.vermont.gov/sites/fpr/fi...servations.pdf

What’s Causing Thin Crowns? Foliage Feeders, Fungi, Fruiting, and other Factors

As mentioned in our August update, we have been observing scattered areas of thin-crowned hardwoods, including some patches with generally brown foliage. Ground checks confirmed that a variety of factors is responsible. In many areas throughout the state, Maple Leaf Cutter is the culprit. These insects have now returned to the forest floor, a “fall migration at your feet” described (including video) in Bryan Pfeiffer’s recent blog. However, in some of the stands there is no sign of maple leaf cutter. We do see a heavy seed crop on sugar maple, which has now turned brown. Some trees with heavy seed had unusually small leaves in the upper crown, and some of these have dropped. In addition, some foliage that was infected by anthracnose in the spring has shriveled and/or fallen prematurely.

For the past few years most of my sugars (NE Ohio) go straight to brown, curl up, then fall. No colorful orange foliage.