A checklist and areography of longhorn beetles (Coleoptera: Cerambycidae) in Rila Mountain

Abstract Background The complex of longhorn beetles in Rila Mt. in Bulgaria was studied by literature data and original biological materials. As a result, 126 taxa from six subfamilies were established, as follows: Prioninae (four taxa), Lepturinae (43 taxa), Necydalinae (two taxa), Spondylidinae (seven taxa), Cerambycinae (31 taxa) and Lamiinae (39 taxa). New information In this study, two new records for Rila Mt. (Stenurellanigranigra and Xylosteusspinolae) and new localities or additional information for 24 cerambycid taxa were reported. The longhorn beetles belong to 18 zoogeographical categories and seven complexes. The European complex occupies a dominant position (37.3%), followed by the Palaearctic (23.8%), Eurosiberian (13.5%), Mediterranean (11.1%), European-Iranoturanian (7.1%), Balkan endemic (4.0%) and Holarctic (3.2%) complexes.


Introduction
Rila is the highest and one of the largest mountains in Bulgaria. The average altitude is 1487 m a.s.l. and the total area -2629 km . The highest peak of the mountain, Musala (2925 m a.s.l.), is the highest on the Balkan Peninsula and in Eastern Europe (Ivanov 1966).
The aim of this study is to sumarise data in entomological literature about longhorn beetles in Rila Mt., to report new records of longhorn beetles and to make zoogeographical analysis of cerambycid fauna in the mountain.

Materials and methods
The longhorn beetles of Rila Mt. were studied by literature data, original records and unpublished materials in entomological collections. The original material was collected on flowers and host plants.
The zoogeographical characterisation of longhorn beetles was made on the basis of recent taxa distribution (Danilevsky 2021). According to Georgiev and Hubenov (2006) and Sakalian and Langourov (2007) conceptions, the established taxa are arranged in 18 chorotypes (areographic categories).
In this study, the taxa of the European complex occupy a dominant position. They are connected with deciduous forests, which cover most of the mountainous territory of Rila. The second place is taken by the species and subspecies belonging to Palaearctic complex. These more euribiont taxa with broad areas of distribution normally are better presented in the high mountains, because of the harsh climatic conditions there. The third and fourth positions take taxa belonging to Eurosiberian and Mediterranean complexes. The high territories, mostly covered by coniferous trees and shrubs, are favourable for distribution of the Eurosiberian taxa. In the lower parts and along the rivers, conditions in Rila Mt. allow penetration of Mediterranean taxa. The refugial character of the region is underlined by the presence of five (4%) Balkan endemic cerambycids.
Similar aerographic characteristics of cerambycid fauna were established in Vitosha Mt.
In conclusion, it should be noted that the finding of 126 taxa (approximately 45% of longhorn beetles in Bulgaria) indicates that this taxonomic group is not yet well-studied and about 50 species and subspecies are expected to be found in future investigations in Rila Mt.