First data on Dolichopodidae (Diptera) of the West Kotlin Nature Reserve (Saint Petersburg, Russia)

First data on Dolichopodidae from the West Kotlin Nature Reserve resulted from the short-term visit (June, 2017) are presented. All 25 collected species are firstly recorded for the Kotlin Island. Lamprochromus semiflavus (Strobl, 1880) and Syntormon filiger Verrall, 1912 are new species for the Leningrad Region and Saint Petersburg. The old records of Lamprochromus bifasciatus (Macquart, 1827) and Syntormon pumilus (Meigen, 1824) from the Region are doubted.


Introduction
The fauna of dolichopodid flies of the Leningrad Region and environs of Saint Petersburg is one of the best studied in Russia with about 220 known species (Stackelberg, 1962;Grichanov, 2006). Nevertheless, none species of long-legged flies was known from the Kotlin Island, located near the head of the Gulf of Finland, 32 km west of the center of Saint Petersburg in the Baltic Sea. In general outline, the island forms an elongated triangle, equal to about 11 km length by about 2 km breadth, with its base directed towards St. Petersburg. The eastern or broad end is occupied by the town of Kronstadt (now a district of St. Petersburg).
The West Kotlin Nature Reserve of regional conservation significance was established in 2012 and occupies the area of 102 hectares on the westernmost tip of the Kotlin Island. The natural objects of special value on the territory of the Reserve are the psammophyte communities on the sandy coasts ( Fig. 1) and the black alder forest. The terrain has natural elevations to 2-4 m above sea level, includes small-leaved forests, maritime marshes ( Fig. 1), peat bogs, and 4 small ponds (Khramtsov et al., 2013).
This paper presents the new species records in detail. Records of 25 species listed below are arranged alphabetically by genus. All specimens listed below have the following label: Russia: Saint Petersburg, West Kotlin Nature Reserve, 16.VII.2017. The authors of this paper make the habitat photos and collect all the specimens (this information is omitted from the species list). Information of each listed species world distribution follows . Type localities are provided and country lists are arranged alphabetically. Material of the newly-recorded species is deposited at the Zoological Institute, St. Petersburg, Russia. All specimens are mounted on pins and placed in the museum drawers. Synonyms are provided in the species list, if only they were mentioned in references related to the Leningrad Region.   REMARKS. This rare in Leningrad Region species was formerly collected only on the Karelian Isthmus by Finnish entomologists (Frey, 1915;Krogerus, 1960 REMARKS. First record of the species in Leningrad Region. According to Grichanov's key (2006), S. filiger females differ from those of close species of the genus in mainly dark fore coxa bearing mostly black hairs and setae; mid coxa with one black seta; fore tibia without serration; frons mat; lower calypter with black cilia. Until recently, some keys, catalogs and checklists (e.g., Negrobov, 1991;Grichanov, 2006) placed S. rufipes (Meigen, 1824) in synonymy to S. pumilus (Meigen, 1824) or considered it a valid species (now an unrecognized species of Rhaphium, see Grichanov, 2013), ignoring a new name Syntormon filiger Verrall, 1912 for Syntormon rufipes (Zetterstedt, 1849, et alii auct.), nec Meigen, 1824 (misidentification); therefore, old records of S. rufipes and S. pumilus from the Leningrad Region (Stackelberg, 1962) Stackelberg (1962).

Conclusion
The Kotlin Island was originally covered with many coniferous trees, which were entirely cut in the first half of 18 th century (Khramtsov et al., 2013). Till the end of 20 th century, the western part of the Island was an area of military activity of the Russian Navy and Army, and it had no access for professional botanists and zoologists. Consequently, the history of flora and fauna dynamics during that period is unknown. The latest trends in soil and flora dynamics on the territory of the West Kotlin Nature Reserve are described and mapped (Khramtsov et al., 2013). Generally, a large portion of the Reserve is covered with natural and semi-natural vegetation consisting of 360 vascular plant species, 53 species of bryophytic, and 154 lichen species.
Our short-term visit to the Kotlin Island has resulted in collection of 25 dolichopodid species. All they are new for the Island. It means that possible faunal composition of the family must be several times more diverse there. Most of the collected species are common and widespread across Europe or even across Palaearctic Region; nevertheless, Dolichopus nubilus, Gymnopternus assimilis, G. metallicus and Thrypticus cuneatus seem to be rare species in the Leningrad Region. Lamprochromus semiflavus and Syntormon filiger are new species for the Region. The Dolichopodidae fauna of the Leningrad Region and Saint Petersburg contains now 223 species (Grichanov, 2006;this paper).