What is this insect?
Your photo shows a Pelecinid Wasp, Pelecinus polyturator (Hymenoptera: Pelecinidae).
The family Pelecinidae is represented by this single species in North America. This bizarre wasp is a parasitoid of white grub larvae that live in the soil feeding on roots. The female thrusts her long tail into the soil to detect a host and then lays one egg on each. The larva then burrows into the beetle larva where it feeds until its development in completed.