Where Have All the Cottonwood Leaves Gone? Into Caterpillers Tummys, Every One (To the Tune of "Where Have All the Flowers Gone")

What the hell is this on Mikey's leg?

Over the last few weeks, we noticed that some of the cottonwood trees around the Cañon land, even the ones close to the Arkansas River, were turning brown. Were they dying?

These were bright green this spring.

Sunday we went down to Cañon so Mikey could caulk the gap between the house and the gutters. We took some time to go down to the ponds, and found that scores of cottonwood trees had been stripped of their leaves or were in the process of turning brown from stress. Who was doing this? We think the culprit is the Western Tent Caterpillar.

This young cottonwood shows a bit of new leaf growth despite all of the old leaves having been nommed by something. There are several somethings on the branches.

This doesn't really look like the tents of the western tent caterpillar - it looks more like the nest of the fall webworm. But fall webworms aren't known for completely defoliating trees.

See the tree on the left? May or June 2011

Same group of trees from a different angle - August 2011.

From what I've been able to learn so far, even the complete defoliation of a tree at this time of year will not be fatal unless there are other stressors present, like drought or a repeated defoliation. But it sure feels bad to look at all those previously lush trees and now see this. And all the little creepy crawlies on the ground. They are everywhere. Ick.