Palaearctic oak gallwasps galling oaks (Quercus) in the section Cerris: re-appraisal of generic limits, with descriptions of new genera and species (Hymenoptera: Cynipidae: Cynipini)

We discuss the taxonomy of oak gallwasps (Hymenoptera: Cynipidae: Cynipini) whose lifecycle involves only Palaearctic oaks (Quercus subgen. Quercus) in the section Cerris. Recent phylogenetic reconstructions support a deep split between such Cerris-associated species in the genera Aphelonyx, Dryocosmus, Plagiotrochus, Neuroterus, Pseudoneuroterus and species and genera associated with oaks in the section Quercus sensu stricto. We reappraise the generic limits of the Cerris-associated genera, proposing new limits for Dryocosmus, Pseudoneuroterus and Neuroterus, establishing a new genus Cerroneuroterus, elevating Latuspina to a genus level, reestablishing the genera Chilaspis and Trichagalma and proposed new species name combinations. We provide a new key to oak gallwasp genera of the Palaearctic and keys to all species of genera associated with Cerris section oaks. We describe five new species, Aphelonyx kordestanica, Trichagalma formosana, Dryocosmus jungalii, Pseudoneuroterus mazandarani, and P. nichollsi.