These links have photos of Pelecinus polyturator.
Pelecinus polyturator is a living relative of the Cretaceous insect Henopelecinus pygmaeus. Both are in the family Pelecinidae. Pelecinus polyturator is often called the American Pelycinid Wasp.
Pelecinus polyturator is native to North, Central, and South America. It resides in forests, gardens, and crop fields. Adults of this species feed on nectar.
The coloration is black and shiny. Males are up to 25.4 mm. (1 in.) in length. Females are as long as 63.5 mm. (2.5 in.) in length. The female's abdomen has six segments. It is five times the length of the rest of her body. The abdomen of the male has a swollen tip. The hindwings of both genders are about one third as long as the forewings. Pelecinus polyturator is not a fast flier.
Females have an articulated metasoma that is elongated and cylindrical. They are parthenogenic; fertilization by males is not necessary for the females to reproduce. Females lay their eggs on grubs of the June beetles (species of the Phyllophaga genus) that are buried in the soil. When the eggs hatch, the young feed on the grubs. The larvae of Pelecinus polyturator spend the winter underground. Adults are seen during summer months.
These publications are references:
University of Wisconsin at Milwaukee - American Pelecinid Wasp (Family Pectinidae)