Cicadas in Switzerland: ascientific overview of the historic and current knowledge of apopular taxon (Hemiptera: Cicadidae) Author Hertach, Thomas Author Nagel, Peter text Revue suisse de Zoologie 2013 2013-06-30 120 2 229 269 journal article 10.5281/zenodo.10114996 0035-418X 10114996 Cicadetta montana s. str. (Scopoli, 1772) German common name: Pechader-Bergzikade ( Hertach, 2010 ) It seems obvious to keep the well-established name “Bergzikade” (= Mountain Cicada ) and add aprefix for all species of the complex in order to demonstrate their close relationship. Cicadetta montana s. str. often can be distinguished from all other Central European species of the clade by its black or very dark coloured basal wing venation (“Pechader” =pitch coloured venation). DISTRIBUTION (Fig. 8) It is difficult to present ahistorical overview of the distribution of C. montana s. str. , because until 2004 only records referring to the whole species complex have been published, with the exception of one record by Artmann (1987) . Nevertheless, we report here some historical data for C. montana s. l. with special focus on records originating from regions where only C. montana s. str. is expected although these are not presented on the map. In acoloured figure Sulzer (1761) drew an accurately shaped C. montana s. l. but named it C. orni .He did not provide any Swiss localities. Referring to this drawing, Fuesslin listed the taxon for Leuk (VS, Sierre region). Heer &Blumer (1846, p. 210) published asporadic occurrence up to the “Wart” for the Canton of Glarus at “ 2000 feet ” (≈ 600 m a.s.l., probably near Schwanden in the Sernf Valley). They call the species erroneously “Blutcicade ( Cicada haematodes )”, but the presence of T.haematodes can be reliably excluded from this region because of its harsh climatic conditions. Bremi (1849 , Bremi in Hagen, 1856b ) gives the most complete overview on the occurrence in the middle of the 19 th century stating that the species is widespread but not common in warm lowland areas including the Zurich region , and that it was found at high altitude locations near aglacier in the Valais . The following further sites have been published: Glarus and Bern ( Milde, 1866 ), afew exactly described places in the Canton of Zurich ( Dietrich, 1872 ; Stoll, 1901 ), in the lower parts of the Engadine Valley (GR) ( Hofmänner,1924 ; Günthart, 1987 ) and in the Finges Forest (VS) ( Bille, 1980 ; Artmann, 1987 ). Pillet (1993) published adetailed map of the Valais populations. FIG.8 Distribution map of Cicadetta montana s. str. including solely acoustically checked records. But since a second species of the complex occurs in this region, conclusions are difficult to reach and his data could unfortunately not been integrated into our map. Notable older voucher specimens for regions which are not well represented in the map, but probably only with this single species, originate in chronological order from Weissenburg(BE) (1849, NAAG), Frauenfeld (TG) (1892 and 1904, NMT), Gerzensee (BE) (1915, NHMB), Erstfeld (UR) (1916, NAAG), Davos Monstein (GR) (1935, ETHZ), Röthenbach i. E. (BE) (1961, NMBE), Hagneck (BE) (1979, NMBE), Isenthal (UR) (1986, NMLS) and Warth-Weiningen (TG) (1997, NMT). In Switzerland , C. montana s. str. is by far the most widely distributed species, although scarcely observed even by many entomologists. The previously published map ( Hertach, 2007 ) has now been complemented with new records mainly from northern Ticino , Grisons and the Lake Geneva Basin. C. montana s. str. occurs in almost all regions of Switzerland but is very rare in the hilly Swiss Plateau. In the entire Grisons except for the Mesocco Valley and for the Poschiavo Valley,in the northern Prealps (Nördliche Voralpen) and in northern Ticino it is the only representative of the family Cicadidae . In the Valais , the most elevated population is established up to 2010 ma.s.l. (Rosswald; Hertach, 2007 ), which as far as we know has not been surpassed by any other Central European Cicadidae . ECOLOGY AND THREAT The habitat requirements of this and the other three species in the C. montana complex have been described in detail ( Hertach, 2007 ). The rather broad habitat requirements have been confirmed within the last years, with a clear preference of sparse Scots Pine ( Pinus sylvestris ) woodlands and dry to mesophilous ecotone habitats. This species is the most difficult to observe due to its preference for singing in the treetops in combination with its rather faint almost ultrasonic song. The species has probably suffered due to habitat loss in the hilly Swiss Plateau judging by the description of Bremi (in Hagen, 1856b ) and some of the sites given by Dietrich (1872) . In Ticino , suitable habitats have been lost by the abandonment of traditional land use. Nevertheless, C. montana s. str. is widely distributed and currently only locally endangered. The European distribution is large but we do not know of other regions with comparable population densities. It is rare in the Italian Alps. Therefore, we assume that Switzerland has aresponsibility for the conservation and maintenance of large populations of this species. C. montana s. str. benefits at warm and sunny sites by thinning out forests on poor soils (especially pine forests) and by improving the structure of forest edges near dry and semidry meadows. Such measures have been conducted by regional authorities over the last decades.