AbstractsBiology & Animal Science

The Nearctic leafhoppers placed in the genus Sorhoanus Ribaut by Oman (1949) were found to belong to several genera, some of which are Holarctic in distribution. None is properly placed in Sorhoanus as presently defined. The genera Sorhoanus, Zelenius Emel'yanov, Boreotettix Lindberg, Lebradea Remane, and Acharis Emel'yanov are redefined and their distribution and relationships discussed. A key is presented for the differentiation of the genera from other related elements in the Nearctic fauna. The characterization of the genera and differentiation of species within the genera are primarily based on the inner genitalia of the male sex and the seventh sternum of the female. Of the 19 species assigned to Sorhoanus by Metcalf (1967), all were studied except acarifer (Lethierry) and fieberi (Metcalf). Twelve of them were placed generically: Sorhoanus contains assimilis (Fallen), schmidti (Wagner), medius (Mulsant and Rey), and hypochlorus (Fieber). Deltocephalus abiskoensis Lindberg, type-species of Arctotettix Linnavuori, is a synonym of Rosenus cruciatus (Osborn and Ball); thus Arctotettix is a junior synonym of Rosenus Oman, Zelenius Emel'yanov contains orientalis (De Long and Davidson), uhleri (Oman) and fidus (Knull). Boreotettix Lindberg contains caricis (Gillette and Baker); Acharis Emel'yanov contains ussuriensis (Melichar); and Lebradea Remane contains flavovirens (Gillette and Baker), and helvinus (Van Duzee). Sorhoanus bicornis Linnavuori is a junior synonym of flavovirens Gillette and Baker, bidentatus De Long and Davidson is the synonym of caricis Gillette and Baker. Three species, Deltocephalus debilis Uhler, Thamnotettix lenis Van Duzee, and Deltocephalus spicatus De Long, heretofore placed in Sorhoanus, appear not to be properly placed in any existing genera and remain of uncertain position. The type-species of Lebradea Remane, calamagrostidis Remane, and three Palearctic Sorhoanus borrowed from Dr. A. F. Emel'yanov; suncharicus Dlabola, tritici (Matsumura), and minutulus Vilbaste, although not occurring in the Nearctic Region are nevertheless discussed in this paper. One Holarctic distributed species, Deltocephalus xanthoneurus Fieber, originally included by Ribaut (1947) in Sorhoanus, and transferred to Cazenus by Oman (1949), is described and returned to Sorhoanus.