D3154: Together forever: New species of Pristocerinae preserved in amber with reproductive behaviors

With over 1,000 species in 26 genera, Pristocerinae are widespread across the world with more species than any other subfamily of Bethylidae. This subfamily of flat wasps is characterized by remarkable sexual dimorphism: Males possess robust bodies, wings, and conspicuous eyes and ocelli, while females are wingless, lack ocelli, and have eyes that are considerably reduced or missing. The vast majority of Pristocerinae species are known from only males or females, and conspecific associations between males and females are rare. In extinct taxa, such associations are almost unknown. However, we discovered two amber specimens that contain new species of Pristocerinae with both a male and female preserved. In the amber piece from the Dominican Republic, the male and female were entrapped while copulating, so it was clear they were from the same species. However, in the Baltic amber piece containing a different new species, the male and female were not preserved mating but instead were found in close association in the fossilized resin. We chose to assign them to the same taxa as conspecifics based on 1) our review of paleoentomological literature detailing the association of conspecifics in fossils, and 2) our knowledge of the reproductive behavior of living Pristocerinae. We believe this male and female may have been trapped in resin millions of years ago much in the same way that an extant male Pristocerinae occasionally transports his mate to her downfall.