Darwin wasps (Hymenoptera, Ichneumonidae) in Lower Eocene amber from the Paris basin

Abstract

Despite their ecological importance, Darwin wasps (Ichneumonidae) are among the most poorly studied groups of organisms. It is therefore not surprising that their fossil record is even more poorly understood than their extant diversity. The early Eocene seems rather fossil-poor regarding Ichneumonidae in amber and only one species, Palaeometopius eocenicus Menier et al., 2004, was described so far from Oise Amber from the Paris basin. Here, two new ichneumonid genera and species, Madma oisella gen. et. sp. nov. and Pappous trichomatius gen. et. sp. nov. are described and the placement of Palaeometopius eocenicus is revised. The three fossils are well-preserved and might represent stem taxa of Tryphoninae and Phygadeuontinae. They are a highly important addition to the early Palaeogene fossil record of Ichneumonidae that otherwise mainly consists of compression fossils, which yield far less detail of the specimens' morphology than amber pieces. Among the more than 1,000 Oise amber pieces examined, only three Ichneumonidae specimens have been found, versus about 60 Braconidae, a ratio very different from other amber deposits. Identification of additional ichneumonid specimens from this period (lowermost Eocene) is of particular importance for a better understanding of the subfamily and species compositions of this family after the K-Pg mass extinction.