P. rubiginosus is, however, extremely similar to P. carolina, and can be found in the same regions; the key morphological difference being the malar area (the "cheek") seen from the side, but this works only for the female wasps. This area and the gena are covered in silvery pubescent hairs. P. rubiginosus is the only Polistes wasp in the P. fuscatus-group to have this characteristic, all other species have this area bare or almost so. Both sexes of P. perplexus can also be distinguished from P. carolina by the coarser transverse ridging of the propodeum. Distribution This species appears to be an endemic of the US. In 1979 Krombein states P. perplexus occurred from Maryland south to Georgia and from there west to southern Illinois, Kansas, Oklahoma and Texas. As of 2020 it has been recorded in the states of Arizona, Arkansas, Florida, Illinois, Kentucky, Louisiana, Missouri, Ohio, Oklahoma, Pennsylvania and Texas. The modern known distribution thus exceeds that given in Krombein in all directions because of problems with identification. The species very similar to P. carolina and may have been under-reported. The specimen from Arizona was collected in 1923 but only properly identified in 2016. The first records from Florida date to 1989. The record from Pennsylvania is from 2005. The distribution largely overlaps with that of P. carolina. Ecology The ecology is poorly known because of the aforementioned confusion with P. carolina. It is a eusocial insect, building nests in sheltered locations such as in hollow trees, or under wooden platforms and inside storage buildings. Adults have been seen feeding on Euthamia graminifolia and/or E. caroliniana in Florida. Conservation The IUCN has not evaluated this species' conservation status. It has been recorded as present in the following protected areas: Archbold Biological Station, Florida, US. Oxley Nature Center, Tulsa, Oklahoma, US. References rubiginosus Insects described in 1836 Taxa named by Amédée Louis Michel le Peletier