A new genus of diapriid wasp (Hymenoptera: Diaprioidea) from mid-Cretaceous Kachin amber with plesiomorphic fore wing venation

The parasitoid wasp family Diapriidae, and the Belytinae subfamily in particular, are abundant in the fossil record, yet understudied. In this contribution, a new genus and species of belytine wasp is described and illustrated, based on two males from the Cenomanian Kachin amber: Eoaclista exquisita gen. et sp. nov. The new taxon is particular as it retains the 1cu-a and 2cu-a veins as tubular on the fore wing, a character previously only found in the Monomachidae for the Diaprioidea superfamily. Eoaclista exquisita gen. et sp. nov. shows that the 2cu-a vein was still present in early diverging Diapriidae, and that it has been lost at least three times in the family, and five times in the superfamily. It also highlights that the relationships within the Diaprioidea are still poorly understood and that wing characters should be treated with caution in a phylogenetic context.