Zoogeographic Characteristics of the Yakutian Tabanid (Diptera, Tabanidae) Fauna

Abstract

Twenty-one species and one subspecies of tabanids belonging to two genera have been established on cattle and horse pastures in Central Yakutia as follows : Chrysops (6 species) and Hybomitra (15 species and one subspecies). In addition, varieties (dark forms) of two types have been found, namely, Hybomitra bimaculata var. bisignata and H. montana var. flaviceps. In Central Yakutia, the Hybomitra genus is distinguished by the greatest species diversity. Hybomitra montana montana (DI 45.29%), H. lundbecki lundbecki (DI 24.97%) and H. ciureai (DI 11.20 %) have been the dominant ones, H. arpadi (DI 5.85%), H. nitidifrons (DI 4.03%) and H. nigricornis (DI 2.97%) subdominant. In total, these species accounted for 94.31% of the collections. Two more species H. lurida (DI 1.88%) and H. lundbecki sibiriensis (DI 1.13%) have been small in number, accounting for 3.1% in the collections. The remaining 13 species and one subspecies refer to the group of rare ones and make up 2.59% in the collections. The mixed zoogeographical structure of the tabanid fauna of Central Yakutia, which is part of the middle taiga subzone, consists of three types of Palearctic fauna : Boreurasian (19 species, one subspecies), arid Afro-Eurasian (one species) and East Asian (one species). The Boreurasian type is distinguished by the greatest species diversity. The Boreurasian fauna species belong to four faunistic complexes as follows : tundra two species taiga 14 species and one subspecies, East Siberian forest one species, and forest-steppe two species. The Afro-Eurasian arid type of fauna includes a steppe complex represented by one species. The East Asian type of fauna consists of the Sino-Japanese faunistic complex, including one species.