The species of the genus Platycheirus Lepeletier & Serville, 1828 (Diptera, Syrphidae) from Taiwan, with a discussion on intersex specimens

Abstract Following an international Diptera expedition in 2016, two new species of Platycheirus Lepeletier & Serville, 1828 were found in Taiwan. A total of three species from three different species groups are now known from Taiwan. The two new species, Platycheirus ferrumitarsis sp. n. and Platycheirus perpes sp. n., are described and their respective placement within the peltatus and ambiguus species groups is discussed. The other species, Platycheirus formosanus Shiraki, 1930, is illustrated and its placement is discussed. It is argued that P. nigritus Huo, Ren & Zheng 2007 should be considered a nomen dubium as it is discussed to be described based on an intersex specimen.