Date of this Version
Szadziewski R, Grogan WL Jr., Sontag E, Bojarski B. 2022. A new genus of predatory midge in the Monohelea complex from Eocene Baltic amber (Diptera: Ceratopogonidae). Insecta Mundi 0919: 1–9.
Monogedania, a new fossil monotypic genus of predatory midge (Diptera: Ceratopogonidae) is described from Eocene Baltic amber and its position within the Monohelea complex is discussed. We discovered that the membranous portion of the aedeagus is extended in Monogedania clunipes (Loew), new combination, which suggests that the aedeagus of some extinct predatory midges can be penis-like. The Eocene Monohelea baltica Szadziewski, is transferred to the genus Schizohelea Kieffer, new combination, and, the previously unknown female is described, and key characters are included in color photographs of its entire habitus, head, distal hind tarsomeres and claws.
The Monohelea complex is a world-wide group of predatory midges that includes six genera in the tribe Ceratopogonini (Wirth and Grogan 1988). Their larvae are aquatic or semiaquatic in mainly small bodies of water and prey on aquatic larvae of a variety of insects. Adult females in this tribe are predators of mostly small nematocerous flies. This complex includes 232 extant species (Borkent and Dominiak 2020). Biting midges of this complex are rare in ambers worldwide (Szadziewski 2018). There are only two named species in the genus Monohelea Kieffer from Eocene Baltic amber (Szadziewski 1988). However, an enigmatic specimen of the genus Austrohelea Wirth and Grogan (sex unknown, no description or illustration) was reported by Schmidt et al. (2018) from Oligocene/Miocene amber of New Zealand; and a species from Eocene Australian (Anglesea) amber of an undetermined genus (Peñalver et al. 2021) may belong to this complex. It is worth noting that in Upper Cretaceous Canadian and Siberian ambers there are species in the fossil genus Peronehelea Borkent (Borkent 1995), that resemble species in the Monohelea complex. Females of Peronehelea have enlarged hind legs and hind claws, however, males in this genus have abdominal tergite 9 with distinct apicolateral processes which are absent or greatly reduced in males of the Monohelea complex. Females of Peronehelea have enlarged hind legs and hind claws, however, males in this genus have abdominal tergite 9 with distinct apicolateral processes which are absent or greatly reduced in males of the Monohelea complex (Szadziewski 1996). Two species from Eocene Baltic amber assigned to Monohelea by Szadziewski (1988) do not entirely resemble any of the genera in the revised Monohelea complex proposed by Wirth and Grogan (1988). Herein, we transfer these two extinct species from Monohelea, to Schizohelea Kieffer (Kieffer 1917), and, the new genus Monogedania, that we describe and illustrate.