Long-legged flies (Diptera: Empidoidea: Dolichopodidae) from Vitosha Mountain, Bulgaria: first contribution and overview

: The paper gives information about 41 dolichopodid species established in Vitosha Mountain. Twenty-one species are newly recorded for the studied area, and one of them, Thrypticus divisus, is new to the fauna of Bulgaria.


Introduction
The family Dolichopodidae belongs to the superfamily Empidoidea of the suborder Brachycera, order Diptera.Family Dolichopodidae is widespread in all zoogeographic regions/zones of the planet without Antarctic.Most species of the family Dolichopodidae are found in moist habitats: on vegetation around rivers, streams, forests, marshes, lakes, etc.A large number of representatives of the genus Medetera and some species of other genera can be found in dry places.Today approximately 8300 species from 261 genera are described worldwide (Grichanov, 2023).For the fauna of Bulgaria 213 species are known (Kechev & Koychev, 2021;Kechev et al., 2022a, b).
Family Dolichopodidae has not been subject of special investigation up to now and only isolated records have been made over the years in Vitosha Mountain.The main purpose of this study is to give new information about the distribution of the family Dolichopodidae in Vitosha Mountain, new data for Bulgaria and to summaries the old and new records of the species in the mountain.

Material and methods
The material for the present work was collected by means of sweep net by the authors from 19 localities in the Vitosha Mountain.The main characteristics of the localities are shown in Table 1 and Fig. 1.The material was collected in the period August-November 2023.After collecting, the adults were put in vials containing 95% ethanol.The species were sorted in the laboratory, using a stereo microscope, Carl Zeiss.For the determination of dolichopodids were used identification guides, mainly by Parent (1938), d'Assis Fonseca (1978), Grichanov (2007) and Negrobov & Stackelberg (1969).Hubenov (1990) was used for the physiographic characteristics of the studied area.The faunistic list includes the following information: name of the species, material (male and female) and sites of collection.Species new to the fauna of the Vitosha Mountain are marked with one asterisk (*) and species new to Bulgaria are marked with two asterisks (**).The material presented in this paper as new to the Vitosha Mountain is housed in Mihail Kechev's collection in the Forest Research Institute, Bulgarian Academy of Sciences, Department of Forest Entomology, Phytopathology and Game Fauna, Sofia, Bulgaria.

Studied area
Vitosha Mountain (Fig. 1) is located in Southwestern Bulgaria, south of Sofia.It is surrounded by the Pernik, Samokov and Sofia Valleys and the Lozenska, Plana, Verila, Golo Bardo and Lyulin Mountains.Vitosha belongs to the Temperate continental climate sub-region of the European continental region and is fully included in the Mountain climate region.Vitosha has 10 peaks above 2000 m a.s.l. and 27 peaks above 1500 m a.s.l., and the highest peak is Cherni Vrah (2290 m).
Vitosha refers to the Illyrian (Balkan) province of the European broad-leaved forest ecoregion.There are four vegetation zones in the mountain: 1. Belt of mixed oak-hornbeam forests.The average height is 1270 m, to which the upper limit of the belt reaches: it varies from 1100 to 1400 m depending on the exposition.Long-legged flies from Vitosha Mountain, Bulgaria: first contribution and overview 2. Belt of beech forests.The average height, at which the upper border of the belt passes, is 1650 m and varies from 1400 to 1840 m at different exposures.
3. Belt of coniferous forests.The average height is 1870 m and, varying from 1700 to 2050 m.
4. Subalpine belt.It covers the territory above the upper forest line.It is characterised by a strong development of psychrophile and mesophyte shrub and grass formations.(Beschovski, 2013).

Discussion
Forty-one species of the family Dolichopodidae known in Vitosha Mountain are recorded in the present paper.Twenty-one of them are new to the investigated area and one species, Thrypticus divisus, is recorded as new to the fauna of Bulgaria.T. divisus is widespread and known from Austria, Belgium, England, Finland, France, Germany, Ireland, Kazakhstan, Russia (European part, Leningrad Region), Sweden (Negrobov & Naglis, 2020).In the Balkan Peninsula it was found from Bosnia and Herzegovina and Croatia (Strobl, 1900).
Further research on the dolichopodids at this mountain will yield many more species, more than 100-120 dolichopodid flies for the area, which is due
Таble 1. Main characteristics of the localities.