This is a very tiny wasp which at first I was not going to photograph as it was in deep shade and would not keep still. But it struck me as being worth photographing after all, and fortunately it did not immediately fly away. This is an interesting little creature, characterized by its very enlarged hind legs, and its pitted thorax. It is a parasitoid of Buprestids in the genus Agrilus, including the notorious emerald ash borer. I saw a number of small Agrilus beetles in the general area.

Thanks to Bug Guide for ID to species level. I knew it was a Chalcidid wasp, but not which species.