Parancistrocerus is a rather large genus of potter wasp

Potter wasp

Potter wasps are a cosmopolitan wasp group presently treated as a subfamily of Vespidae, but sometimes recognized in the past as a separate family, Eumenidae.-Recognition:...

s whose distribution spans over the Nearctic

Nearctic

The Nearctic is one of the eight terrestrial ecozones dividing the Earth's land surface.The Nearctic ecozone covers most of North America, including Greenland and the highlands of Mexico...

, Palearctic

Palearctic

The Palearctic or Palaearctic is one of the eight ecozones dividing the Earth's surface.Physically, the Palearctic is the largest ecozone...

, Oriental and Neotropical regions. Their species are notable for having a smopth depression acting as an acarinarium

Acarinarium

An acarinarium is a specialized anatomical structure which is evolved to facilitate the retention of mites on the body of an organism, typically a bee or a wasp. The term was introduced by Walter Karl Johann Roepke.-Evolution:...

 at the base of the second metasomal tergum and hidden under the first metasomal tergum. This acarinarium serves as shelter for symbiotic deuteronymphs of mites in the family Winterschmitiidae. Most of the species bear a transverse carina on the first metasomal tergum and the whole body of many neotropical species have a faint submetallic luster. A pair of medial pits on the anterior face of the pronotum and the expansion of the tegula

Tegula

Tegula can mean:* Teulada, Italy, called Tegula during Roman times* Tegula , a genus of marine snails* Tegula , a part of the wings attached to the mesothorax, in various insects...

e put this genus close to the genus Stenodynerus

Stenodynerus

Stenodynerus is a rather large genus of potter wasps whose distribution spans over the Nearctic, Palearctic, Oriental and Neotropical regions. Most of its species lack a transverse carina on the first metasomal tergum...

and many species of both genera are somewhat difficult to assignate to their respective genus.