A rare Plecia Wiedemann, 1828 (Diptera: Bibionidae) from the Paleocene of Menat, France

Abstract

The fly family Bibionidae is extremely frequently found in the lacustrine insect assemblages between the late Eocene and the latest Miocene of France. For instance, the Bibionidae represent 25% of the fossil insects collected at Cereste (total 7,466 specimens, Oligocene, Lubéron, France) (Nel, 1991). It is not the case in the Paleocene lacustrine Konservat-Lagerstätte of Menat (Puy-de-Dôme, France). In this outcrop, we could find only four specimens of Bibionidae in a collection of ca. 6,768 insects. Two of these were previously described by Nel (2007) and Nel & Kundura (2023), respectively in the genera Plecia and Bibio. They are so rare, around 0.1% of the total number of insects in the collections we could study, that it is worth describing the two others herein. These specimens were in the studied collection but we did not notice them before now.