The study deals with a taxonomic and faunistic revision of the orthopteran insects (order Orthoptera) in Bulgaria.
The data were gathered from all available literature sources, rich collection materials, a newly collected material (most of the latter gathered from poorly investigated regions in Bulgaria), and by field observations. For the first time in this country bioacoustic methods for investigation of insect taxonomy have been used. Combined with karyosystematic and morphological investigations they allowed complete taxonomic revision of the genus Isophya in Bulgaria. Phylogenetic analysis of the Isophya modesta species group, based on morphology and bioacoustics has been accomplished using PAUP*4.0, revealing the phylogenetic relationships between its taxa. The species group Poecilimon ornatus was also revised by means of bioacoustic and morphological methods and new systematic changes were proposed within the genera Platycleis, Pholidoptera, Eupholidoptera, Tettigonia, Ephippiger, Troglophilus, Tartarogryllus, Paracaloptenus, Oedipoda, Stenobothrus и Chorthippus.
As a result of the study, 25 synonymies were established, the status of four taxa was changed and the status of one species was restored. Four taxa are found to represent possible new species.
Based on critical analysis of the literature data, determination of rich collection material, newly collected material and field observations, two genera, one subgenus, 31 species and three subspecies were recorded for the first time for Bulgaria. The occurrence of 21 species and subspecies was not confirmed, therefore, they are deleted from the list of Bulgarian fauna. The horizontal distribution of all 218 species and subspecies found to occur in this country is defined and mapped in an UTM-grid on 214 maps. The data collected on the vertical distribution and phenology of the taxa are presented and discussed in relation to the species’ origin and the prevailed xerothermophily of the group. On the basis of their conservation status and distribution, priority species and subspecies were defined and 18 unique and representative communities of Bulgarian orthopterans were identified.
As a result of the study, significant levels of endemism and species diversity, which determine the high conservation value of this group, have been established for the Bulgarian orthopteran fauna.