Peyerimhoffia vagabunda - new sciarid species (Sciaridae, Diptera) for the entomofauna of Ukraine

Peyerimhoffia vagabunda (Winnertz, 1867) is a widespread sciarid species (Diptera, Sciariadae) which occurs in 20 European countries and Asia (recorded in Kazakhstan, Altai, Primorsky Krai and China). Previously, P. vagabunda as well as the other species from the genus Peyerimhoffia Kieffer, 1903 was unknown to the Ukrainian entomofauna. hi the framework of taxonomic and ecological research on Sciaridae in Ukraine some chorological and faunistic peculiarities of P. vagabunda have been studied. We collected material during expeditions and excursions in different biotopes of Ukraine from 2013 to 2018 by the method of non-count sweeping with an entomological net. Collected imagoes were placed into 5 ml vials with 76% ethanol. In the laboratory, the fixed material was dehydrated in absolute ethanol and mounted on slides in Euparal. We have found five new localities of P. vagabunda in three regions - Kyiv (one locality in the National Natural Park "Holosiivskyi"), Volyn (four localities in the National Natural Park "Tsumanska Puscha") and Odesa (one locality in the National Natural Park "Tuzlovski Lymany"). All findings were registered in four biotope types: G1.A16 Sub-continental hombeam-oak forests, E5.22 Mesophile fringes - post forest-felling mixed-species grassland, G1.95 Birch fresh and dry forests and G1 .C3 Robinia plantations. Accordingly, in Ukraine we discovered three separate P. vagabunda populations located in Kyiv, Odesa and Volyn regions. Between the specimens from these populations we have detected some morphological differences. Male imagoes from Volyn and Odesa regions fully match previous descriptions of the species, but the specimen from the Kyiv population is somewhat different. Specifically this concern to the wing structure - the stM length of the Kyiv specimen is only a bit longer than the length of M-fork; one seta is present on the y; c is longer than was previously described and occupies 3/4w, but not 2/3w. Our discovery of P. vagabunda in Ukraine partially eliminates the disjunctive nature of the species' range and implies its continuity. Imagoes of this species occur mainly in wet and shaded forests, but can enter the nearest coastal or ecotone meadows or penetrate caves. Our discovery of P. vagabunda in Ukraine is the first record of any Peyerimhoffia representative in our county. In Europe nine Peyerimhoffia species are known and they can potentially be detected in the territory of Ukraine. Considering this, a key to identification of these species is given in the article.