I was doing a report on the Chestnut Oak today, and remembered something I thought should be followed up on. At one point, I noted that more than 90% of the Chestnut oak trunks had dead caterpillars on them. All of them just dead, stopped in their tracks. Below is one example I photographed. Today I did a google search, and from what I'm seeing there is a fungus amongst us that kills the gypsy moth caterpillars (spongy moth to be politically correct).
biocontrol.entomology.cornell.edu