Atlas of xerothermic weevils (Coleoptera Curculionoidea). Distribution in Poland

Abstract

The atlas includes 116 species of weevil, whose ranges have been presented in analytical maps. Both the distribution of localities and the author’s views on the migration of species can be read from these. The interpretation of ranges is the result of areographic analysis. It was carried out on the basis of a concept of migration routes (Mazur 2001) that refers to the history of Vistulian steppe tundra. This concept makes it possible to arrange contemporary localities by the specific migration route to which they probably belong. The occurrence of xerothermic weevils is dependent on the presence of specific habitats, which are not, however, in harmony with Poland’s modern climate. Accordingly, these habitats may only develop under particularly favourable edaphic conditions (chalky soils), and assuming an appropriate exposure of the locality (usually south-facing), which affects its microclimate. It is for this reason that the range of xerothermic species is of an island type. In terms of its phytosociology, the vegetation of xerothermic environments is diverse. Matuszkiewicz (2001) distinguishes 19 associations here, which he divides into 6 classes (Table 3). This compilation contains not only xerothermic grassland associations (class 1) but also thermophilous and xerophilous forest, scrub, ruderal, and segetal associations. These share similar physical properties of their environment, i.e. habitat. Many species of weevil also occur in other plant communities, which do not meet the criteria of the classification presented here (such as the initial and degradation phases of communities, succession stages). The maps were made using the Gnomon program, version 3.0. On most of these, localities are placed in two layers, called here the historic and the contemporary. The historic layer is composed of localities recorded pre-1950, which were not updated after this date. All other localities have been included in the modern layer. The time boundary between these is notional, though it coincides with a considerable fall in field work activity in the 1940s. For individual localities or their groups, the year of the most recent record has been given in the historical layer. Distinguishing this layer is not meant to suggest that the localities belonging to it no longer exist. It was only the author’s intention to draw the attention of the user of the atlas to regions and areas which require a new inventory of species (e.g. the Silesian Lowland and the Sudete).