Pholeuonopsis (Pholeuonopsis) sljivovicensis, sp. n. (Figs. 1–9) Etymology. After the village of Šljivovica (near Čajetina, Mt. Zlatibor, western Serbia), where the type locality of the new species is situated—the Cave by the Užice-Mt. Tara road. Material examined. Holotype male, seven paratype males, and 17 paratype females collected from pitfall traps with rotten meat as bait in the Cave by the Užice-Mt. Tara road, village of Šljivovica, near Čajetina, 642 m a.s.l., Mt. Zlatibor, western Serbia, 18.09 - 02.11.2013, leg. M. Petković & F. Bosco; a paratype male and a paratype female collected by hand, idem, 18.09. 2013, leg. D. Antić & S. Ćurčić. The type specimens are deposited in the collection of the Institute of Zoology, University of Belgrade - Faculty of Biology, Belgrade, Serbia (IZFB- 14 / 77- 103). Diagnosis. The new species clearly differs from all existing Pholeuonopsis taxa from underground habitats and deep soil in Serbia, Bosnia and Herzegovina, and Montenegro. It is phenetically closest to the three species from Serbia, Pholeuonopsis (Pholeuonopsis) magdelainei, P. (P.) cvijici and P. (P.) zlatiborensis. However, there are numerous distinctions between the new species and these three species, and they are presented below. Pholeuonopsis (Pholeuonopsis) sljivovicensis sp. n. is easily distinguished from P. (P.) magdelainei by its longer body size (3.92 mm in males, 4.08 mm in females vs. 3.80 mm), the antennal length in males (extending beyond the mid-elytra level vs. reaching two-thirds of the elytra), form of the antennomere VIII (more elongate vs. less elongate), shape of the lateral pronotal margins anteriorly (more rounded vs. less rounded), maximum width of the pronotum (slightly before the mid-portion vs. at the hind pronotal angles), shape of the hind pronotal angles (short, less protruding backwards vs. elongate, more protruding backwards), height of the mesosternal carina (high vs. low), shape of the elytra (inversely ovate vs. oval), size of the scutellum (large vs. small), shape of the parameres apically (more widened vs. less widened), position of the parameral setae (almost equidistant vs. the two upper setae being close-set), form of the gonostyli (less curved vs. more curved), position of the outer gonostyl seta (at the level between the two inner setae vs. at the level of the second inner seta), and form of the spermatheca (more curved vs. less curved) (Jeannel 1924; Ćurčić et al. 2006; current paper). Pholeuonopsis (Pholeuonopsis) sljivovicensis sp. n. is easily distinguished from P. (P.) cvijici by its somewhat longer body size (3.62–4.04 mm in males, 3.86–4.42 mm in females vs. 3.81–3.90 mm in males, 3.76–4.09 mm in females), the antennal length (extending beyond the mid-elytra level in males, while not exceeding the mid-elytra level in females vs. extending beyond the mid-elytra level in both sexes), form of the antennomeres VIII (more elongate vs. less elongate) and XI (ovoid vs. sub-elliptical), combined pronotum and elytra/antenna length ratio (1.36 in males and 1.53 in females vs. 1.33 in males and 1.46 in females), the pronotum length/width ratio (0.81 vs. 0.75), shape of the lateral pronotal margins anteriorly (more rounded vs. less rounded), maximum width of the pronotum (slightly before the mid-portion vs. at the hind pronotal angles), shape of the hind pronotal angles (short, less protruding backwards vs. elongate, more protruding backwards), shape of the posterior pronotal margin in males (somewhat convex medially vs. straight), height and shape of the mesosternal carina (high, more rounded, with slightly convex anterior edge vs. low, more acute, with more convex anterior edge), shape of the lateral elytral margins anteriorly (almost straight vs. somewhat impressed), the elytra length/width ratio (1.53 vs. 1.49), length of certain protarsomeres (protarsomere I slightly shorter than the following two protarsomeres combined vs. protarsomere I longer than the following two protarsomeres combined), form of the median lobe (dorsal view) distally (thickened, with more rounded apex vs. not thickened, with more pointed apex), length and shape of the parameres (slightly shorter than the median lobe, more widened distally, sigmoidly curved in lateral view vs. much shorter than the median lobe, less widened distally, regularly arcuate in lateral view), form of the basal bulb in dorsal view (more elongate vs. less elongate), shape of the median lobe in lateral view (less curved, more widened basally vs. more curved, less widened basally), form of the copulatory piece in dorsal view (with two basal short straight structures and one apical sub-triangular structure vs. with two basal and two median long, straight structures, without apical sub-triangular structure), shape of the male abdominal sternite IX (urite) (more oval vs. sub-ovate), form of the gonostyli (less curved vs. more curved), and shape of the spermatheca (more elongate, somewhat narrower vs. less elongate, somewhat thickened) (Ćurčić & Brajković 2002; Ćurčić et al. 2006; current paper). Finally, Pholeuonopsis (Pholeuonopsis) sljivovicensis sp. n. is easily distinguished from P. (P.) zlatiborensis by its longer body size (3.92 mm in males, 4.08 mm in females vs. 3.60 mm in males, 3.90 mm in females), the presence/absence of eye-spots (absent vs. present), the antennal length (extending beyond the mid-elytra level in males, while not exceeding the mid-elytra level in females vs. extending beyond the mid-elytra level in both sexes), form of the antennomere VIII (more elongate vs. less elongate), combined pronotum and elytra/antenna length ratio (1.36 in males and 1.53 in females vs. 1.33 in males and 1.43 in females), shape of the pronotum both anteriorly (more rounded vs. less rounded) and posteriorly (less constricted vs. more constricted), height and form of the mesosternal carina (somewhat lower, more rounded vs. somewhat higher, more pointed), shape of the elytra (inversely ovate vs. ovate), maximum width of the elytra (somewhat anterior to the mid-level in both sexes vs. at the mid-level in males and somewhat anterior to the mid-level in females), the female/male elytral width ratio (1.07 vs. 1.11), shape of the lateral elytral margins anteriorly (almost straight vs. inconspicuously impressed), form of the median lobe (dorsal view) distally (sub-parallel vs. gradually narrowing proximally), shape of the median lobe apex dorsally (shorter, more rounded vs. longer, more pointed), form of the parameres in dorsal view (somewhat curved, more widened distally vs. almost straight, less widened distally), position of the parameral setae (almost equidistant vs. the two lower setae being close-set), form of the basal bulb in dorsal view (more elongate vs. less elongate), form of the copulatory piece in dorsal view (with two basal short, straight structures and one apical subtriangular structure vs. with two basal short, curved structures, without apical sub-triangular structure), form of the male abdominal sternite IX (urite) (more elongate vs. less elongate), form of the gonostyli (somewhat curved vs. almost straight), number of the inner gonostyl setae (two vs. three), distribution of the outer gonostyl seta (situated at the level between the two inner setae vs. situated at the level between the second and third inner setae), and shape of the spermatheca (more curved, somewhat narrower vs. less curved, somewhat wider) (Ćurčić et al. 2006; current paper). Description. Medium-sized. Body length: 3.92 mm (3.62–4.04 mm) in males, 4.08 mm (3.86–4.42 mm) in females. Body pholeuonoid, elliptic, elongated, from yellowish-brown to reddish-brown (Fig. 1). Integument shiny, pubescent, microsculptured. Head elongate, slightly longer than wide, without eyes or eye-spots (Fig. 1). An inconspicuous occipital carina present. Head dorsally covered with numerous densely distributed small punctures and small yellowish erect setae. Vertex with a shallow impression. Labrum emarginate, with a few long setae. Penultimate maxillary palpomere well widened apically, the ultimate one being narrow, short, narrowing apically. Antennae moderately long, slender, widening distally (Fig. 1). Combined pronotum and elytra length to antenna length ratio: 1.36 (males) and 1.53 (females). Antennae inserted at about mid-head level, shorter than the body (Fig. 1), extending beyond the mid-elytra level in males, while not exceeding the mid-elytra level in females. Antennomere I widened apically, shorter than antennomere II. Antennomere II longer than antennomere III. Antennomere VIII the shortest, elongately sub-spherical. Antennomeres I–VI moderately thickening apically, and antennomeres VII and IX–XI well broadened. Distalmost antennomere ovoid, longer than the penultimate one. Pronotum small, sub-bell-shaped, wider than long (length/width ratio 0.81), widest slightly before the midportion, covered with dense, short, yellowish laid setae and impressed punctures (Fig. 1). The lateral margins bordered, sigmoidly shaped. Posterior pronotal margin shorter than the base of elytra. Both anterior and posterior pronotal margins somewhat convex medially. Fore pronotal angles rounded, obtuse, and the hind ones acute, pointed, prominent, somewhat protruding backwards. Pronotal disc weakly convex, with two basal and two median shallow impressions. Mesosternal carina high, sub-triangular, obtuse, carrying a few teeth and a number of setae on the posterior edge (Fig. 2). The anterior edge slightly convex, while the posterior one somewhat concave. Metasternum without carina. Elytra elongate, inversely ovate (length/width ratio 1.53), wider in females than in males (female/male elytral width ratio 1.07) (Fig. 1). The maximum width reached somewhat anterior to mid-elytral level in both sexes. The lateral margins well-chitinized, almost straight anteriorly. Marginal furrows relatively wide, shallow, gradually narrowing towards elytral apex. Humeri obtuse, rounded. Elytral disc convex, gradually declining anteriorly, but steeply declining posteriorly, with numerous short, yellowish laid setae and impressed punctures. Scutellum large, triangular. Elytral apex rounded. Legs long, slender, with the femora thickened basally (Fig. 1). Tibiae somewhat curved, moderately thickening apically. Meso- and metatibiae with a few fine spines each. Protarsi 4 -segmented in both sexes. The first protarsomere nearly three times as long as wide, slightly shorter than the following two protarsomeres combined. Tarsal claws long, thin, sharply pointed. Male genitalia as presented in Figs. 3–5. Aedeagus medium-sized, well-sclerotized, stout (Figs. 3 and 4). Basal bulb well-developed, rounded in dorsal view (Fig. 3), while huge in lateral view (Fig. 4). Median lobe in dorsal view thickened and sub-parallel distally, somewhat narrowing proximally, sub-apically rounded, apically with a pointed apex that is somewhat rounded anteriorly (Fig. 3). Median lobe longer than parameres. Median lobe in lateral view curved in the anterior portion, gradually narrowing apically, with a pointed beak-like apex (Fig. 4). Parameres long, thin, somewhat curved exteriorwards dorsally and sigmoidly curved laterally, narrowing apically, but with a widened apex each (Figs. 3–5). Each paramere with three apical, almost equidistant setae (Fig. 5). Inner sac elongated, tubular. Copulatory piece consisting of a basal phanera, two basal sclerotized short, straight structures and one apical sub-triangular structure, along with two weakly sclerotized bands (Fig. 3). Male abdominal sternite IX (urite) well-developed, oval (Fig. 6). Female genitalia (Figs. 7 and 8). Gonostyli elongated, thin, gradually narrowing distally, somewhat curved (Fig. 7). Each stylus with a single apical seta, two inner setae and one outer seta. The outer seta situated at the level between the two inner setae. Spermatheca small, unique, hook-like, strongly curved, somewhat narrowing apically, well-sclerotized (Fig. 8). Female abdominal segment VIII large, transverse, with a short narrow anterior process, setose (Fig. 9). Bionomy and distribution. The new species was found under rocks and in pitfall traps in the posterior, totally dark part of the Cave by the Užice-Mt. Tara road, village of Šljivovica, near Čajetina, Mt. Zlatibor, western Serbia (Fig. 10). The species prefers wet clay cave walls and floor, where it probably feeds on filtrated organic matter from trickling water. The type locality of the new species is inhabited by the blind leiodid species— Leptinus testaceus Müller, 1817, which usually lives in nests of mammals, birds and hymenopterans, but is frequently found in caves as well (Perreau 2000). The new species probably belongs to an old phyletic lineage of Mesogeid (alpine ranges of southern Europe and Africa) origin, like some other Pholeuonopsis taxa from Serbia (Ćurčić & Brajković 2002; Ćurčić et al. 2006). It belongs to the eastern Mesogeid range (southern Balkan Peninsula and Asia Minor), with the initial activity in the Cretaceous and the main tectonic phase in the Eocene-Miocene (Guéorguiev 1977). The species is both relict and endemic to the Dinarides in western Serbia, like other Serbian congeners inhabiting some cave habitats (Jeannel 1924; Guéorguiev 1977; Ćurčić & Brajković 2002; Ćurčić et al. 2006). The endemic differentiation of Pholeuonopsis spp. and the relative taxa on the Balkan Peninsula was facilitated by the great Alpine Orogeny, paleoclimatic events, and subsequent evolution of the underground karstic relief, which yielded numerous new epigean and hypogean niches suitable for the preservation of the old and autochthonous fauna (Ćurčić et al. 2012, 2013, 2014 a).