I took the mystery picture on my black Walnut tree in my front yard this past week. When I first saw it I thought, "what in the world is that?" I blew on it and it moved so I knew something was alive.

After researching, I determined that they are Walnut Caterpillars. They look this way when they molt.

There’s some controversy about destroying them because of the valuable parasites that use them as a host. However, it can be devastating to your tree. So I took a glove and removed them into a bag.