A NEW SOIL PSEUDOSCORPION, RONCUS URSI N. SP., FROM WESTERN SERBIA (NEOBISIIDAE, PSEUDOSCORPIONES)

A new species of the pseudoscorpion genus Roncus L. Koch (Neobisiidae) from Serbia (Kulina, Mt. Medvednik) is described and its diagnostic characters are illustrated. Interrelations with phenetically close congeners are analyzed; in addition, the presence/absence of microsetae proximal to the trichobothria eb and esb and presence/absence of one or two outstanding tubercles on the interior lateral side of pedipalpal femur are established as important taxonomic characters.


INTRODUCTION
The low number of taxa of a particular group of arachnids in Serbia can be attributed to several possible reasons.The interest of specialists might be focused on other groups of animals: the small body size and cryptic way of life impedes the gathering of material needed for study, the low densities of specimens of a particular group (the troglobitic and troglophilic forms in particular), and the general inaccessibility of the habitats these animals populate.

Setal designations follow
Female genital area: unknown.
Cheliceral galea low (Fig. 6).Cheliceral palm with six setae.Movable finger bears one seta.Fixed and movable cheliceral fingers have 11 and 15 teeth, respectively.Flagellum 8-bladed.The proximalmost blade is the smallest, all other blades of the same length.All blades are pinnate on the anterior side.Chelicera is 1.42 -1.44 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 (Fig. 3).Interior and lateral granulations are formed on the pedipalpal femur and chelal palm.All other pedipalpal articles smooth (Fig. 1 and 3).The fixed and movable chelal fingers carry 59 and 59 -61 small and contiguous teeth, respectively (Fig. 1).
Trichobothriotaxy: eight and four trichobothria are present on the fixed and movable chelal fingers, respectively (Fig. 1).Trichobothrium st closer to t than to sb; sb equidistant to st and b.Trichobothrium ist slightly closer to est than to isb.Five microsetae present anterior to eb and esb (Fig. 1).Chelal finger longer than chelal palm (Table 1).The pedipalpal chelal length-to-breadth ratio is 3.315 -3.40.Pedipalpal femur is 3.14 -3.40 times longer than broad.The pedipalpal tibia is 2.20 -2.33 times longer than wide (Table 1).Tibia IV, basitarsus IV, and tarsus IV each with a single long tactile seta (Fig. 2).Subterminal tarsal seta furcate, each branch with a few tiny spinules.
Tactile seta ratios, measurements and morphometric ratios are presented in Table 1.
Differential diagnosis -Roncus ursi n. sp. is easily distinguished from Roncus krupanjensis B. Ćurčić, Rađa, S. Ćurčić, and N. Ćurčić in the following aspects: body length, carapacal length and breadth, carapacal length-to-breadth ratio, cheliceral lengthto-breadth ratio, pedipalpal length to body length ratio, pedipalpal femur length-to-breadth ratio, pedipalpal chela length-to-breadth ratio, length of chelal palm to breadth of chela ratio, length of chelal finger to length of chelal palm ratio, as well as in many oth-  er linear measurements and morphometric ratios of different body parts, including the appendages (Table 1).
In addition, it should be noted that the new species differs from its other congener, R. radji B. Ćurčić, Rađa, S. Ćurčić, and N. Ćurčić from western Serbia in almost all quantitative and qualitative characters, as is the case with R. krupanjensis.Distribution and remarks.-According to present knowledge (Ćurčić, 1972, 1984, 1988, 1992a, b;Ćurčić and Beron, 1981;Ćurčić et al., 1993, 2004, 2010a, b, c, d, e, f, g;2011a, b, c, d, e, f, g, h;Hadži, 1937), the new species of Roncus inhabits only the slopes of Mt.Medvednik in western Serbia.It is regarded as an endemic neobisiid from the central area of the Balkan Peninsula.It should be noted that R. ursi n. sp.carries a number of microsetae proximal to eb and esb; some other species of the genus carry one or two large tubercles on the interior and lateral side of the pedipalpal femur.Both characters, however, are lacking in other species of this taxon.Therefore, it is possible that they reflect some supraspecific relations, which are yet not clearly understood.