A new species of Bocchus from upper Eocene Rovno amber (Hymenoptera, Dryinidae)

A new fossil species of Dryinidae (Hymenoptera, Chrysidoidea) from upper Eocene Rovno amber (Ukraine) is described: Bocchus rex sp. nov. It is compared with two other species of Bocchus known from European amber: B. primaevus Martins & Melo from Baltic amber and B. schmalhauseni Perkovsky, Olmi, Vasilenko, Capradossi & Guglielmino from Rovno amber. A new key to the Cretaceous and Paleogene species of Bocchus is presented. The Dryininae are the most common representatives in all the amber dryinid faunas since the mid-Cretaceous. The Rovno amber fauna is an exception; possible explanations for the abundance of Bocchus species within this amber are presented.