These peonies are the old fashioned Karl Rosenfeld, Sarah Bernhardt and Festiva 
Maxima. I purchased three new peonies this spring at Home Depot...blaze, miss america and do tell...I don't mind buying young, inexpensive plants and trying my success at them.
We live on 6 acres of land with quite a few trees, particulary a thick woods to our north. Basswood, a few oak, ash and boxelder make up the bulk of trees. This year we are having an unusually bad infestation of forest tent caterpillars. They have stripped bare most of our trees. At one point, I couldn't walk in the house without stepping on worms and carrying them in on my clothes. They mounded over the flower planters that I couldn't move inside. The rest of my many flower containers were moved into a cool dark shed, where some developed root rot. I should have left them out. They walked over my vegetable and perennial gardens, but didn't eat the plants, except for my three william baffin roses, which they relished. They also ate one apple tree, left the stems only!!
We have had these worms in the past, but tolerated them. We will have to aerial spary next year. I couldn't stand another spring like this one. They spray with bt which is supposedly a fairly safe option.
OK...here are pictures of the apple tree and a rose: They were fully leafed out. 
You 
can also see the bare trees behind the apple tree.
Forest tent caterpillars are "born" from moth eggs encased (no web or tent) around the stems of trees, preferably high in the tree. (Eastern tent caterpillars develop in webbed tents you can easily see in trees.) The newly hatched worms eat the leaves of a tree, drop and march to another tree (hence, often wrongly called armyworms) and eat until their cycle ends. Then they cocoon in remaining plant leaves and turn into small brown moths in about a week. And the cycle continues. 
The worms are now towards the end of their cycle and slowing down.
