The Leptophlebiidae of New Guinea (Ephemeroptera, Choroterpinae, Thraulini).

The first global account of the diversity of the Ephemeroptera family Leptophlebiidae in New Guinea is provided, based on collections of nymphs collected throughout the island and in some neighboring islands by Michael Balke (Munich) and his collaborators mainly between 2006 and 2011. All specimens belong to the subfamily Choroterpinae and to the tribe Thraulini. All species can be accommodated in three genera: Eaton, 1881, Grant & Peters, 1993, and The genus is divided into two subgenera, namely and Peters, Gilles & Edmunds, 1964, which is removed from synonymy with . Thirty-one new species are described herein. The subgenus Thraulus is reported with nine new species: Thraulus (Thraulus) eloisae, Thraulus (Thraulus) granti, Thraulus (Thraulus) longinquus, Thraulus (Thraulus) nabire., Thraulus (Thraulus) noe, Thraulus (Thraulus) ogea, Thraulus (Thraulus) timorensis., Thraulus (Thraulus) wemale., and Thraulus (Thraulus) sp. A. Five new species of the subgenus Masharikella are described: Thraulus (Masharikella) iteris, Thraulus (Masharikella) johannisluci., Thraulus (Masharikella) pascalae, Thraulus (Masharikella) samueli., and Thraulus (Masharikella) sp. B. Besides the seven known species placed in the genus , 11 new species are described: ., , ., , ., , , ., ., and two unnamed species. Similar to , the new genus is endemic to New Guinea and is currently restricted to the eastern part of Papua New Guinea. It is composed of six new species: ., ., , , , and (Peters & Tsui, 1972), the type species of the genus Grant & Peters, 1993 is redescribed, and the synonymy of with is followed but shown to be not completely satisfactory. A key for all currently known species of leptophlebiid nymphs occurring in the area is provided. Compared to the work of Cozzarolo et al. (2019) who investigated the genetic diversity of this fauna, our results appear to be more conservative, some molecular operational taxonomic units (MOTUs) being lumped together based on morphology. The affinities of this fauna with neighbouring areas of Southeast Asia and Australia are also discussed. Although this study reveals a large part of the hidden biodiversity of New Guinea, it is far from being complete and a huge number of new species of Leptophlebiidae await formal description.