The planthopper genus Stenocranus in Canada: implications for classification of Delphacidae (Hemiptera)
AbstractThe Canadian species of Stenocranus Fieber are keyed by external characters correlated with species concepts defined by known genitalic characters. Stenocranus is differentiated from Terauchiana Matsumura (Asian; here reported from the New World for the first time) and Embolophora Stål (from Africa) by the remarkable development of the female pygofers, which completely conceal the ovipositor. Based on both head and genitalic characters, the genus is divided into two subgenera: typical Stenocranus with many Old World species and two Canadian species, and subgenus Codexnov. for other New World species. The type of Delphax dorsalis Fitch, 1851 is a specimen of Stenocranus pallidus Beamer, 1946 syn. nov., and "S. dorsalis" sensu Beamer is S. unipunctatus (Provancher, 1872). A lectotype of Delphax vittata Stål, 1862 is designated for the taxon S. unipunctatus (sensu Beamer, nec Provancher); its paralectotypes are specimens of S. acutus Beamer. The apparent evolutionary relationships of this fauna to other species of the world Stenocranini and within the superficially similar Saccharosydnini reveal numerous homoplasies and dramatic autapomorphies, contrasted with only a few reliable synapomorphies. A hierarchical classification of Delphacidae, based on the most distinctive synapomorphies, defines subfamily Delphacinae as encompassing at least four tribes: Vizcayini, Stenocranini, Tropidocephalini, and Delphacini, with "Kelisiinae" reduced to subtribe of Stenocranini and "Saccharosydnini" placed within Tropidocephalini.