Sergeev M.G.1,2, Efremova O.V.2.2020. [Distribution patterns of assemblages of Orthoptera on plains following an west-east gradient along the 55° N latitude in the south-eastern part of the West Siberian Plain] // Euroasian Entomological Journal. Vol.19. No.3: 117–123 [in Russian, with English summary].
1 Institute of Systematics and Ecology of Animals, Siberian Branch, Russian Academy of Sciences, Frunze Str. 11, Novosibirsk 630091 Russia. E-mail: mgs@fen.nsu.ru
2 Novosibirsk State University, Pirogova Str. 2, Novosibirsk 630090 Russia.
ABSTRACT. Orthopteran assemblages are analyzed for the first time the west-east (continental) gradient along 55° N latitude in the south-eastern part of the West Siberian Plain (Russia). 36 orthopteran species are found, including some potential pests, especially the lesser marsh grasshopper (Chorthippus albomarginatus (De Geer)). A weak trend of species richness decreases along this gradient is revealed. The orthopteran assemblages associated with the steppe meadows and meadow steppes may be explicitly divided in three groups; their distribution pattern may be explained by local landscape peculiarities, primarily drainage. The first group includes the assemblages with dominance of species preferring more or less xerothermic habitats (usually Glyptobothrus biguttulus (Linnaeus)) in the forest-steppes near the Ob River. The second group unites the assemblages on the right side of the Irtysh River; there are many mesohydrophilic forms including some katydids (Tettigonia cantans (Fuessly), Poecilimon intermedius (Fieber)) and grasshoppers (mainly Chorthippus parallelus (Zetterstedt)). The third group is distributed near watershed plains and are dominated by the lesser marsh grasshopper.
KEY WORDS: grasshoppers, katydids, Baraba Plain, forest-steppe, biological diversity, assemblage, classification, ordination.