Grasshoppers in steppe areas of the south-eastern West Siberian Plain: Centennial transformations of biodiversity

Abstract

The goal of this paper is to evaluate some general trends of species range shifts in the steppe areas of the south-eastern West Siberian Plain. Two sets of distribution data of grasshoppers are compared: (1) for the first half of 20th century and (2) for 1972 – 2019. A series of digital maps was generated by Map Info. Shifts of species distribution patterns are discussed. All grasshopper species may be split into three groups: (1) acridids without evident changes in their distribution; (2) species with local range boundaries shifted northwards and northeastwards; new colonies of such forms are usually found in the northern steppe and even in the forest-steppe and/or on the right side of the Ob River; (3) grasshoppers which became rare. Among them is the Siberian grasshopper, the very common pest in the first half of the 20th century. Some changes into grasshopper distribution may be associated with global warming, but others can be explained by regional and local variations in human activities. Extension, intensification, and changes of human activities may result in continuous elimination of some local populations. This means that the general strategy of management of acridid assemblages and populations should incorporate both data and technologies concerning rare species populations and new approaches to pest control and monitoring.

The Handsome Cross Grasshopper Oedaleus decorus (Germar, 1825) (Orthoptera: Acrididae) as a Neglected Pest in the South-Eastern Part of West Siberian Plain

“…Hence, O. decorus has become one of the most widely distributed grasshopper over the south-eastern parts of West Siberian Plain and occupies all steppe areas, the southern parts of the forest-steppes between the Irtysh and Ob Rivers, and the forest-steppes on the eastern side of the Ob River where it colonized some transformed habitats [1,2].…”

“…The south-eastern part of West Siberian Plan lies in the central section of the range of Oedaleus decorus (Germar, 1825) or the handsome cross grasshopper [1,2]. This acridid species is widely distributed over the Eurasian semi-arid areas (mainly across foreststeppes, steppes, semi-deserts, Mediterranean and mountain dry grasslands), from the Atlantic coast to the Pacific one [3][4][5][6][7][8].…”

“…Later, in the end of the 20th century, the general area of arable fields significantly decreased from about 11 million to 10.2 million ha (for two regions) [27]. In the second half of the last century, such ecosystems' transformations and, perhaps, global climatic variations as well resulted in species distribution changes [1,2,28]. The aims of this publication are to show how the distribution of O. decorus over West Siberian Plain has shifted, to estimate what climatic factors are essential for the species, how its distribution can change in the coming years, and to discuss some forecasts of its dispersal until 2040.…”