The taxocene of lichen-feeding darkling beetles (Coleoptera, Tenebrionidae: Helopini) in a forest-steppe ecotone

Abstract

The taxocene of lichen-feeding darkling beetles from the tribe Helopini is studied in the steppes of the south of Rostov Province. The species of lichens grazed on by the representatives of this tribe are identified for the first time and dependence of circadian activity and spatial distribution of adults on temperature and air humidity is shown. Global warming and human activities may have caused degradation of steppe lichen communities that formed the dietary base for the lichen-feeding darkling beetles in natural ecosystems. As a result, 3 out of 4 beetle species completely left steppe biotopes for tree shelterbelts. This caused a change in the trophic relationships (transition from epigeic to epiphytic lichens) and in the spatial distribution of darkling beetles, promoted the establishment of competitive interactions, and increased the duration of circadian and seasonal activity due to the lengthening of the periods with optimum temperature and air humidity for each species.