RONCUS JELASNICAE, A NEW EPIGEAN PSEUDOSCORPION OF THE GENUS RONCUS L. KOCH, 1873, FROM EAST SERBIA

A new endemic epigean species from the Jelašnička Klisura Gorge, near Niš, East Serbia, is erected, described and illustrated. Its main morphometric characters and important diagnostic features are analyzed and compared to those of its two closest congeners, Roncus jarilo Ćurčić and Roncus titilin Ćurčić, from East and Southeastern Serbia, respectively.


INTRODUCTION
A major breakthrough in the study of both epigean and cavernicolous species of the genus Roncus L. Koch, 1873 in Serbia has been carried out during the past 18 years by Ćurčić (1993), Ćurčić et al. (1993Ćurčić et al. ( , 2004Ćurčić et al. ( , 2006Ćurčić et al. ( ), and Dimitrijević (2000)).The known number of taxa assigned to this genus from seven in 1993 has risen to present 23.Of these, 13 species are cave-dwelling and 10 inhabit leaf-litter and humus.The majority of these species are relict and endemic forms for Serbia.
In this study, careful examination of the collected material from the Jelašnička Klisura Gorge, near Niš, East Serbia, resulted in establishing a new pseudoscorpion species, Roncus jelasnicae n. sp., probably an endemic and relict form that inhabits the area studied.Etymology .-The new species is named after its type locality, the Jelašnička Klisura Gorge.
Cheliceral galea low (Fig. 8).Cheliceral palm with six setae.Movable finger bears one seta.Fixed and movable cheliceral fingers with 11 and 10 teeth respectively.Flagellum eight-bladed.The proximalmost blade is the smallest, all other blades of same length.All blades are pinnate on the   anterior side.Chelicera is 1.45 times longer than broad (Table 1).
Apex of the pedipalpal coxa (manducatory process) with four long setae.Pedipalpal femur with a single small exterior tubercle.Interior and lateral granulations are found on the pedipalpal femur and chelal palm.All other pedipalpal articles smooth (Figs. 1, 2).The fixed and movable chelal fingers carry 50 and 46 small and contiguous teeth respectively (Fig. 1).
Trichobothriotaxy: Eight and four trichobothria are present on the fixed and movable cheliceral fingers respectively (Fig. 1).Trichobothrium ST closer to T than to SB; SB closer to ST than to B. Trichobothrium IST closer to EST than to ISB.Six microsetae present anterior to EB and ESB (Fig. 4).Chelal finger slightly longer than chelal palm (Table 1).The pedipalpal chelal length to breadth ratio is 1.05.Pedipalpal femur is 2.80 times longer than broad.The pedipalpal tibia is 2.04 times longer than wide.
Tibia IV, basitarsus IV, and tarsus IV each with a single long tactile seta (Fig. 3).Subterminal tarsal seta furcate, each branch with a few tiny spinules.
Tactile seta ratios, measurements, and morphometric ratios as presented in Table 1.
Distribution.-According to the present knowledge, the new species inhabits only the Jelašnička Klisura Gorge.It is regarded as an endemic neobisiid from Southeastern Serbia.Qualitative distinctions between females of these two species include: absence of tiny dorsal denticulations on trochanter (present in R. jarilo, absent in R. jelasnicae n. sp.); interior granulations on the pedipalpal femur and chelal palm (more developed in R. jarilo than in R. jelasnicae n. sp.); the shape of the pedipalpal tibia (more oval-like in R. jarilo than in R. jelasnicae n. sp); the form of the epistome (distinctly triangular in R. jarilo, knob-like with rounded top in R. jelasnicae n. sp.); and the relative disposition of the trichobothrium IST (in R. jelasnicae n. sp. it is closer to EST and in R. jarilo this trichobothrium is closer to ISB).
As in the case of the females of R. jarilo, females of Roncus jelasnicae n. sp.differ from females of Roncus tintilin from East Serbia in generally smaller body size (Table 1).Further differences include: the pedipalpal femur length to breadth ratio (2.80 in R. jelasnicae n. sp. vs. 3.22-3.58Remarks.-The establishing of new Roncus species in Serbia in recent years confirms the opinion of Ćurčić (1993) that the taxonomy of this genus is still far from being complete.On the grounds of the available data it is evident that this genus is in the process of an intensive radiation and divergent differentiation into new species in Serbia (as well as in regions bordering on Serbia) (Ćurčić and Beron, 1981;Ćurčić, 1984).

RONCUS JELASNICAE,
Specimen examined.-Holotype female from the Jelašnička Klisura Gorge, near Niš, East Serbia, collected by I. Karaman on 25 October 2008.Holotype female is deposited in the collection of the Institute of Zoology (IZB), Faculty of Biology, 11000 Belgrade, Serbia.
in R. tintilin); the pedipalpal tibia length to breadth ratio (2.04 in R. jelasnicae vs. 2.055-2.34 in R. tintilin); the pedipalpal chela length to breadth ratio (2.84 in R. jelasnicae n. sp. vs. 3.04-4.07 in R. tintilin); the ratio of the chelal palm length to chelal breadth (1.45 in R. jelasnicae n. sp. vs. 1.53-2.10 in R. tintilin); and the relative disposition of the trichobothrium IST (in R. jelasnicae n. sp.IST is closer to EST, in R. tintilin IST is equidistant from EST and ISB).Pedipalpal granulations are more developed on the interior side of the pedipalpal femur in R. tintilin than in R. jelasnicae n. sp.Pedipalpal trochanter in R. jelasnicae n. sp.lacks tiny denticulations present on the same article in females of R. tintilin.