Madagopsina gen. n. and Gracilopsina gen. n. (Diptera: Diopsidae) from Madagascar with description of four new species

Madagopsina gen. n. and Gracilopsina gen. n. are described as endemic Diopsidae taxa for Madagascar. Three Madagascan Diopsidae, earlier alternately placed in Diopsis, Eurydiopsis or Cyrtodiopsis (also as Teleopsis), are now referred to Madagopsina gen. n., while two of these three species proved to be conspecific. This gives rise to Madagopsina apollo (Brunetti) comb. n. and Madagopsina apographica (Séguy) comb. n. = anjahanaribei (Vanschuytbroeck) syn. n. The two species are redescribed. Madagopsina apographica proved to have a mixed type series. Three new species are allocated to the genus as Madagopsina freidbergi sp. n., Madagopsina parvapollina sp. n. and Madagopsina tschirnhausi sp. n. For Eurydiopsis vadoni Vanschuytbroeck (later also placed in Cyrtodiopsis and Teleopsis) the genus Gracilopsina gen. n. is erected, leading to Gracilopsina vadoni (Vanschuytbroeck) comb. n. Gracilopsina vadoni is redescribed and is shown to have a mixed type series. One new species is allocated to the genus as Gracilopsina sinespina sp. n. A key is presented to the two genera and seven species. Madagascar now counts five Diopsidae genera and 12 species, of which two genera and 11 species are endemic. The genus Cladodiopsis is no longer an endemic Madagascar genus as it also occurs in the Comoros. The phylogenetic position of Madagopsina gen. n. is discussed based on molecular data. The intra- and intergeneric phylogeny of both new genera is discussed based on morphology and geometric morphometrics analyses of wing shape. Data are presented on sexual dimorphism with respect to eye span in the genera. The resulting allometric lines (eye span/body length) are also included in the phylogenetic analysis. The allometric lines for the closely related M. parvapollina sp. n., and the much larger M. apollo are compared and discussed. Allometric slopes and intercepts are identical for females of both species, while in males allometric slopes are identical, but intercepts differ considerably. An identical phenomenon was found in two closely related East African Diopsis species with a small and a large species. Various morphological characters, including eggs, are discussed. The importance of intersternite 1–2 and synsternum 7+8 as differential characters is indicated.