DUVALIUS (PARADUVALIUS) PETROVICI SP. N. AND D. (P.) SOTIROVI SP. N. (CARABIDAE: TRECHINAE: TRECHINI): TWO NEW TROGLOBITIC GROUND BEETLES FROM EASTERN AND SOUTHEASTERN SERBIA

The following two new troglobitic trechine ground beetle species are described from two caves in eastern and southeastern Serbia: Duvalius (Paraduvalius) petrovici sp. n., from the Resavska Pećina Cave, village of Jelovac, near Despotovac, Kučajske Planine Mts., and D. (P.) sotirovi sp. n., from the Ogorelička Pećina Cave, village of Sićevo, near Niš, Svrljiške Planine Mts. The new species considerably differ from the related taxa. All important morphological characteristics of the species, along with the diagnoses and images of the taxa are presented. These represent relicts and endemics of eastern and southeastern parts of Serbia and are of great age (probably Tertiary or even before).

Several field trips in eastern and southeastern Serbia in 2012 and 2013, organized by the Institute of Zoology, University of Belgrade -Faculty of Biology, resulted in the discovery of two new cavedwelling trechine ground beetle species.The current study contains descriptions and diagnoses of the new beetle taxa.The diagnosis of Duvalius (Paraduvalius) petrovici sp.n. is based on a thorough analysis of the type series of one male and eight females collected in the Resavska Pećina Cave, village of Jelovac, near Despotovac, Kučajske Planine Mts., while the diagnosis of D. (P.) sotirovi sp.n. is based on a thorough analysis of the type series of two males collected in the Ogorelička Pećina Cave, village of Sićevo, near Niš, Svrljiške Planine Mts.

MATERIALS AND METHODS
The collected ground beetle specimens were analyzed in the laboratories of the Institute of Zoology, University of Belgrade -Faculty of Biology, Belgrade, Serbia.The male and female genitalia were removed from the bodies and fixed on microscope slides in a medium composed of Canada balsam and xylol.The beetle individuals were then glued on paper la-bels and analyzed as dry specimens ) stankovitchi by its smaller size (4.12-4.65 mm vs. 5.00-6.20 mm), length/width ratio of the head (wider than long vs. as long as wide), length of the antennae (exceeding somewhat over the middle of the elytra vs. almost reaching the mid-elytra level), length/width ratio of the pronotum (wider than long vs. longer than wide), maximum width of the pronotum (slightly above the anterior fourth vs. around the anterior third), shape of the lateral pronotal margins (rounded anteriorly, then almost straight, but slightly concave right above the hind pronotal angles vs. rounded anteriorly, somewhat concave pos- teriorly) and posterior pronotal angles (somewhat acute-angled vs. almost right-angled), position of the first pair of pronotal setae (slightly above the anterior fourth of the pronotum vs. at the anterior third of the pronotum), length/width ratio of the elytra (1.71 times as long as wide vs. 2.00 times as long as wide), position of the first pair of elytral discal setae (on third elytral striae, at the level between the third and fourth humeral setae vs. on fourth elytral interstriae, at the level of the fourth humeral setae), shape of the aedeagus (less convex dorsally around the basal third, basal bulb without an anterior narrowing, median lobe gradually narrowing apically, the apex less curved downwards vs. more convex dorsally around the basal third, basal bulb with an anterior narrowing, median lobe sub-parallel, the apex more curved downwards), number of parameral setae (4-5 vs. 4), and size and shape of the copulatory piece (as long as three-fourths of aedeagus length, sub-apically narrowing, apically pointed vs. slightly longer, apically narrowing, apex obtuse) (Jeannel, 1923(Jeannel, , 1928;;present study).
Duvalius (Paraduvalius) petrovici sp.n. is easily distinguished from D. (P.) trifunovici by its smaller size (4.46 mm vs. 4.78 mm), body color (paler vs. somewhat darker), presence/absence of hairs on the head except for cheeks (present vs. absent), depth of the frontal furrows (slightly deeper somewhat in front of the first two-thirds vs. of the same depth along its length), length of the antennae (more exceeding over the middle of the elytra vs. slightly exceeding over the middle of the elytra), maximum width of the pronotum (slightly above the anterior fourth vs. around the anterior fourth), shape of the anterior (less concave vs. more concave) and lateral pronotal margins (rounded anteriorly, then almost straight, slightly concave right above the hind pronotal angles vs. rounded anteriorly, somewhat concave posteriorly) and posterior pronotal angles (somewhat acute-angled vs. obtuse-angled), position of the first pair of pronotal setae (slightly above the anterior fourth of the pronotum vs. at the anterior third of the pronotum), maximum width of the elytra (between the anterior half and three-fifths vs. slightly below the mid level), shape of the shoulders (obtuse-angled, more elevated vs. not obtuse-angled, less elevated), position of the first (at the level between the third and fourth humeral setae vs. at the level of the fourth humeral setae) and second pairs of elytral discal setae (around three-fifths of elytral length vs. somewhat below the mid-elytra level), shape of the aedeagus (the median lobe thinner, slightly curved basally, then straight, basal bulb elongated vs. the median lobe thicker, slightly curved, basal bulb rounded), number of parameral setae (4-5 vs. 4), and shape of the urite (less elongated vs. more elongated) (Vrbica et al., 2013;present study).
Duvalius (Paraduvalius) petrovici sp.n. is easily distinguished from D. (P.) bogovinae by its body color (paler vs. somewhat darker), depth of the frontal furrows (slightly deeper somewhat in front of the first two-thirds vs. slightly deeper in the first third), form and size of the eyes (quite reduced, in the form of a line vs. atrophied, in rare cases visible, lenticular, 0.08 mm long and 0.03 mm wide, with a darkened border), presence/absence of the ommatidia (absent vs. present), length of the antennae (exceeding somewhat over the middle of the elytra vs. in the holotype male exceeding slightly over the middle of the elytra, while in females almost reaching the middle of the elytra), maximum width of the pronotum (slightly above the anterior fourth vs. around the anterior fourth), shape of the anterior (less concave vs. more concave), lateral (rounded anteriorly, then almost straight, but slightly concave right above the hind pronotal angles vs. rounded anteriorly and slightly concave posteriorly) and posterior pronotal margins (mostly straight vs. slightly concave) and anterior (less prominent vs. more prominent) and posterior pronotal angles (less pronounced acute-angled vs. more pronounced acute-angled), position of the first pair of pronotal setae (slightly above the anterior fourth of the pronotum vs. between the anterior fourth and third of the pronotum), shape and maximum width of the elytra (not sub-parallel, between the anterior half and three-fifths vs. sub-parallel, slightly above the mid level), length/width ratio of the elytra (1.71 times as long as wide vs. 1.86 times as long as wide), shape of the shoulders (obtuse-angled vs. not obtuseangled), number of well-depressed elytral striae (three inner ones vs. four inner ones), position of the first pair of elytral discal setae (around the anterior fourth of elytral length vs. between the anterior fifth and fourth of elytral length), shape of the aedeagus (strongly bent around the basal third, dorsally slightly convex in that part, median lobe curved basally, then straight, gradually narrowing towards the apex, abruptly narrowing sub-apically, basal bulb slightly elongated vs. somewhat curved, median lobe slightly curved in the basal half, then almost straight, slightly narrowing towards the apex, basal bulb rounded), number of parameral setae (4-5 vs. 4), shape and size of the copulatory piece (narrower, as long as threefourths of aedeagus length vs. wider, around as long as three-fifths of aedeagus length), and size of the urite (slightly longer than aedeagus vs. about of the same size as aedeagus) (Ćurčić et al., 2014; present study).
Duvalius (Paraduvalius) petrovici sp.n. is easily distinguished from D. (P.) beljanicae by its bigger size (4.46 mm vs. 4.32 mm), body color (paler vs. somewhat darker), presence/absence of hairs on the head except for cheeks (present vs. absent), form and size of the eyes (quite reduced, in the form of a line vs. reduced to different degree, from lenticular, small, with a darkened border, 0.07 mm long and 0.01 mm wide, to almost atrophied, in the form of a line, or completely absent), shape of the anterior pronotal margin (scarcely concave vs. mostly straight), anterior (less rounded vs. more rounded) and posterior pronotal angles (more pronounced acute-angled vs. less pronounced obtuse-angled) and marginal pronotal furrows (narrow and shallow vs. wide and deep at the level of the anterior pronotal angles, then narrow and shallow), position of the first pair of pronotal setae (slightly above the anterior fourth of the pronotum vs. around the anterior fourth of the pronotum), maximum width of the elytra (between the anterior half and three-fifths vs. slightly below the mid level), shape of the shoulders (obtuse-angled, more elevated vs. not obtuse-angled, less elevated), number of welldepressed elytral striae (three inner ones vs. two inner ones), distance between the humeral setae (the shortest distance between the third and fourth setae vs. the shortest distance between the first and second setae), position of the first (around the anterior fourth of elytral length, at the level between the third and fourth humeral setae vs. somewhat above the anterior third of elytral length, somewhat below the level of the fourth humeral setae) and second pairs of elytral discal setae (around three-fifths of elytral length vs. around two-thirds of elytral length), shape of the aedeagus (more bent around the basal third, dorsally slightly convex in that part, median lobe curved basally, then straight, gradually narrowing towards the apex, more abruptly narrowing sub-apically, basal bulb massive, slightly elongated vs. less bent around the basal third, not convex in that part, median lobe slightly curved, at first gradually narrowing towards the apex, then less abruptly narrowing apically, basal bulb medium-sized, rounded), number of parameral setae (4-5 vs. 4), shape and size of the copulatory piece (with more acute apex, as long as three-fourths of aedeagus length vs. with less acute apex, around as long as two-thirds of aedeagus length), and size of the urite (less longer than aedeagus vs. more longer than aedeagus) (Ćurčić et al., 2014; present study).
Description -Medium-sized.Total body length (without mandibles): 4.12-4.65 mm.Body elongated, covered with dense hairs of moderate length.Body color reddish-light brown.Head and pronotum each with a polygonal microsculpture (Fig. 1).
Head stout, rounded, slightly wider than long.Frontal furrows deep, complete, arcuate, slightly deeper somewhat in front of the first two-thirds.Cheeks convex, covered with dense hairs of moderate length.The rest of the head covered with tiny, rare hairs.Eyes quite reduced, in the form of a line, without ommatidia.An arcuated pre-ocular furrow present.Mentum tooth bifid.Antennae of moderate length, exceeding somewhat over the middle of the elytra.Antennomere II shorter than antennomere IV.Antennal article XI about three times as long as wide (Fig. 1).
Pronotum small, wider than long, sub-cordate, widest slightly above the anterior fourth, slightly wider than head, narrowing towards the base.Anterior pronotal margin scarcely concave.Anterior pro-notal angles prominent and rounded.Lateral pronotal margins rounded anteriorly, then almost straight, but slightly concave right above the hind pronotal angles.Posterior pronotal angles prominent, somewhat acute-angled, sharp.Posterior pronotal margin mostly straight.Pronotal disc convex, with a median furrow.Marginal furrows narrow and shallow.Basal foveae wide, deep, and slightly punctate (Fig. 1).
Elytra elongated, ovoid, 1.71 times as long as wide, widest between the anterior half and threefifths of elytral length.Shoulders rounded, obtuseangled, somewhat elevated.Elytral apex rounded.Marginal furrows narrow and deep.Elytral disc slightly convex.The first three inner striae developed, well depressed.Outer striae present in a form of more or less pronounced rows of points.Inner interstrial spaces convex (Fig. 1).
Legs long and thin.Fore tibias with a longitudinal fissure each.Male protarsomeres I and II dilated (Fig. 1).
Chaetotaxy: Head with two pairs of supraorbital setae.Pronotum with two pairs of pronotal setae.The first pair located slightly above the anterior fourth of the pronotum, while the second pair situated in the posterior pronotal angles.Each humerus with four setae.The longest distance between the second and third setae, while the shortest distance is between the third and fourth setae.The second seta right next to the marginal furrow.The first, third and fourth setae away from the furrow, with the first one being closest to it, and the fourth farthest from it.With two discal setae on each elytron.The first pair of elytral discal setae situated on third striae, around the anterior fourth of elytral length, at the level between the third and fourth humeral setae.The second pair of elytral discal setae situated on third striae, around threefifths of elytral length (Fig. 1).
Bionomy and distribution -The new species was found in the lower level of the Resavska Pećina Cave, village of Jelovac, near Despotovac, Kučajske Planine Mts., eastern Serbia.It lives on vertical wet walls and speleothems in a few chambers of the cave and feeds on insects and other cave-dwelling invertebrates.For the moment, the species is known only from the type locality.
Remarks -The new species belongs to the "stankovitchi" group of species based on the shape of the elytra, presence of unpronounced shoulders (rounded, not angled), absence of laid hairs on the vertex, presence of a longitudinal fissure on the fore tibias and the first elytral discal setae located below the level of the third humeral setae (Guéorguiev, 1971).It is worth mentioning that the discovery of the new troglobitic trechine species was unexpected in the Resavska Pećina Cave since it has long been known to scientists, is well explored and has been described in detail.It was quite surprising to find the species there considering that the cave is lighted and open to tourist visits (Petrović, 1971).During our visits, additional arthropod species were recorded in the cave as well: Plusiocampa christiani Condé & Bareth, 1996 (Diplura: Campodeidae), Serbosoma kucajensis (B.Ćurčić & Makarov, 1998) (Diplopoda: Anthroleu-cosomatidae), Centromerus serbicus Deltshev, 2002, Porrhomma convexum (Westring, 1851) (Araneae: Linyphiidae), and Neobisium cf.carpaticum Beier, 1935 (Pseudoscorpiones: Neobisiidae) (Djurović, 1998;Ćurčić and Makarov, 2000;Deltshev and Ćurčić, 2002).
(Figs. 6-9) Etymology -The new species is named after the welknown Serbian biologist Prof. Dr. Spas Sotirov (Faculty of Science, University of Niš, Serbia), who investigated the whole area of southeastern Serbia for a long time.
Diagnosis -Duvalius (Paraduvalius) sotirovi sp.n. clearly differs from its closest congeners from caves and pits in southeastern and eastern Serbia.These are Duvalius (Paraduvalius) winkleri, D. (P.) rtanjensis, and D. (P.) milutini.However, there are numerous distinctions between the new species and the other three species and these are presented below.Duvalius (Paraduvalius) sotirovi sp.n. is easily distinguished from D. (P.) winkleri by its smaller size (4.12 mm vs. 4.20 mm), form of the eyes (lenticular, with a darkened border vs. in the form of a whitish elongated ring, with no trace of pigment), length/ width ratio of the pronotum (wider than long vs. longer than wide), presence/absence of hairs on the pronotum (present vs. absent), position of the first pair of pronotal setae (slightly above the anterior third of the pronotum vs. around the anterior fourth of the pronotum), shape of the shoulders (somewhat elevated vs. fairly prominent), depth of the marginal elytral furrows (shallow vs. deep), number of well-depressed elytral striae (two inner ones vs. three inner ones), position of the first (slightly above the anterior sixth of elytral length vs. around the anterior fifth of elytral length) and second pairs of elytral discal setae (around the mid-elytra level vs. somewhat below the mid-elytra level), and size and shape of the aedeagus (small, constricted proximally, convex dorsally from around the middle to its sub-apical part, then narrowing towards the apex, apex acute, basal bulb slightly elongated vs. massive, constricted proximally, convex dorsally from around the basal twothirds to its sub-apical part, apex obtuse, basal bulb rounded) and copulatory piece (as long as around a half of aedeagus length, less widened, elongated, without spines, less incised proximally vs. as long as a third of aedeagus length, wide, less elongated, with a large number of fine spines apically, deeper incised proximally) (Jeannel, 1923(Jeannel, , 1928;;present study).
Duvalius (Paraduvalius) sotirovi sp.n. is easily distinguished from D. (P.) rtanjensis by its smaller size (4.12 mm vs. 4.29-4.41mm), body color (somewhat darker vs. paler), hairiness of the body (with tiny, rare hairs vs. with more abundant hairs of moderate length), length/width ratio of the head (as long as wide vs. slightly wider than long), shape of the cheeks (less convex vs. more convex), size and form of the eyes (quite reduced, in the form of a line vs. 0.10 mm long and 0.03 mm wide, lenticular), presence/absence of the ommatidia (absent vs. present), shape of the marginal pronotal furrows (wide and deep at the level of the anterior pronotal angles, then narrow and shallow vs. narrow and shallow), anterior pronotal margin (slightly convex medially vs. slightly concave) and posterior pronotal angles (acute-angled vs. almost right-angled), position of the first pair of pronotal setae (slightly above the anterior third of pronotal length vs. around the anterior fourth of pronotal length), length/width ratio of the elytra (1.66 times as long as wide vs. 1.73 times as long as wide), shape of the shoulders (somewhat elevated vs. lowered), distance between the humeral setae and the position (the longest distance between the third and fourth setae; the first seta right next to the marginal furrow, the second, third, and fourth setae away from the furrow, with the second one being closest to it, and the fourth farthest from it vs. humeral setae equidistant; the first and second setae located at the edge of the marginal furrow), depth of the marginal elytral furrows (shallow vs. deep), number of well-depressed elytral striae (two inner ones vs. four inner ones), position of the first (slightly above the anterior sixth of elytral length, somewhat below the level of the second humeral setae vs. about at the anterior fifth of elytral length, at the level of the second humeral setae) and second pairs of elytral discal setae (around the midelytra level vs. slightly below the mid-elytra level), size and shape of the aedeagus (smaller, more bent, median lobe more elongated, constricted proximally, convex dorsally from around the middle to its sub-apical part, then narrowing apically, basal bulb more elongated, less rounded, apically narrowed vs. larger, less bent, median lobe less elongated, slightly convex dorsally around the basal third, of almost the same length towards the apex, with a slight sub-  -9.Duvalius (Paraduvalius) sotirovi sp.n. from the Ogorelička Pećina Cave, village of Sićevo, near Niš, Svrljiške Planine Mts., southeastern Serbia.7 -holotype male, aedeagus (lateral view); 8 -holotype male, aedeagus (dorsal view); 9 -holotype male, abdominal sternite IX (urite).Scales = 0.20 mm.apical widening, abruptly narrowing apically, basal bulb less elongated, more rounded, apically not narrowed), copulatory piece (as long as around a half of aedeagus length, unifid, apically pointed vs. as long as around a third of aedeagus length, bifid, apex in the form of two slightly pronounced lobes), and size of the urite (slightly longer than aedeagus vs. scarcely shorter than aedeagus) (Vrbica et al., 2013;present study).
Duvalius (Paraduvalius) sotirovi sp.n. is easily distinguished from D. (P.) milutini by its bigger size (4.12 mm vs. 3.95 mm), body color (somewhat darker vs. paler), hairiness of the body (with tiny, rare hairs vs. with dense hairs of moderate length), length/width ratio of the head (as long as wide vs. slightly wider than long), depth of the frontal furrows (slightly deeper somewhat in front of the first two-thirds vs. slightly deeper in the first half), shape of the cheeks and the hairiness (less convex, covered with rare hairs vs. more convex, covered with dense hairs), size and form of the eyes (quite reduced, in the form of a line vs. reduced, small, 0.09 mm long and 0.03 mm wide, lenticular, with a darkened border, the anterior margin convex, the posterior one scarcely convex, almost flattened), presence/absence of the ommatidia (absent vs. present), maximum width of the pronotum (widest at the anterior third vs. widest at the level between the anterior fourth and third), shape of the marginal pronotal furrows (wide and deep at the level of the anterior pronotal angles, then narrow and shallow vs. narrow and shallow), anterior pronotal margin (slightly convex medially vs. mostly straight) and anterior (more prominent vs. less prominent) and posterior pronotal angles (more pronounced acute-angled vs. less pronounced acute-angled), position of the first pair of pronotal setae (slightly above the anterior third of the pronotum vs. between the anterior fourth and third of the pronotum), length/width ratio of the elytra (1.66 times as long as wide vs. 1.73 times as long as wide), shape of the shoulders (obtuse-angled vs. not obtuse-angled), position of the humeral setae (the first seta right next to the marginal furrow; the second, third and fourth setae away from the furrow, with the second one closest to it vs. the second seta right next to the marginal furrow; the first, third and fourth setae away from the furrow, with the first one closest to it), depth of the marginal elytral furrows (shallow vs. deep), number of well-depressed elytral striae (two inner ones vs. three inner ones), position of the first (slightly above the anterior sixth of elytral length vs. between the anterior sixth and fifth of elytral length) and second pairs of elytral discal setae (around the mid-elytra level vs. slightly above the mid-elytra level), shape of the aedeagus (more curved, more constricted proximally, convex dorsally from around the middle to its sub-apical part, then narrowing apically, median lobe narrower, more elongated, apex acute, basal bulb more elongated vs. less curved, less constricted proximally, convex dorsally from in front of the middle to its sub-apical part, then narrowing apically, median lobe wider, less elongated, basal bulb less elongated), size and shape of the copulatory piece (as long as around a half of aedeagus length, narrower, gradually narrowing apically vs. slightly shorter than a half of aedeagus length, broader, abruptly narrowing apically), and shape of the urite (more elongated vs. less elongated) (Ćurčić et al., 2014; present study).
Head stout, rounded, as long as wide.Frontal furrows deep, complete, arcuate, slightly deeper somewhat in front of the first two-thirds.Cheeks slightly convex, covered with tiny hairs.Eyes quite reduced, in the form of a line, without ommatidia.An arcuated pre-ocular furrow present.Mentum tooth bifid (Fig. 6).
Pronotum small, wider than long, sub-cordate, slightly wider than head, widest at the anterior third, narrowing towards the base.Anterior pronotal margin slightly convex medially.Anterior pronotal angles prominent and rounded.Lateral pronotal margins rounded in the first half and somewhat concave posteriorly.Posterior pronotal angles prominent, S. ĆURČIĆ ET AL. acute-angled, sharp.Posterior pronotal margin slightly concave.Pronotal disc convex, with a median furrow.Marginal furrows wide and deep at the level of the anterior pronotal angles, then narrow and shallow.Basal foveae wide, deep, and slightly punctate (Fig. 6).
Elytra elongated, ovoid, 1.66 times as long as wide, widest around the mid level.Shoulders rounded, obtuse-angled, somewhat elevated.Elytral apex rounded.Marginal furrows narrow and shallow.Elytral disc slightly convex.The first two inner striae developed, well depressed.Outer striae present in the form of more or less pronounced rows of points.Inner interstrial spaces convex (Fig. 6).
Chaetotaxy: Head with two pairs of supraorbital setae.Pronotum with two pairs of pronotal setae.The first pair located slightly above the anterior third of the pronotum; the second pair situated in the posterior pronotal angles.Each humerus with four setae.The longest distance between the third and fourth setae.The first seta right next to the marginal furrow.The second, third and fourth setae away from the furrow, with the second one closest to it, and the fourth farthest from it.With two discal setae on each elytron.The first pair of elytral discal setae situated on third striae, slightly above the anterior sixth of elytral length, somewhat below the level of the second humeral setae.The second pair of elytral discal setae situated on third striae, around the mid-elytra level (Fig. 6).
Aedeagus small, almost regularly curved over the whole of its length, constricted proximally, convex dorsally from around the middle to its sub-apical part, then narrowing apically (Fig. 7).Apex acute, basal bulb medium-sized, slightly elongated (lateral view) (Fig. 7).Aedeagus almost straight, median lobe slightly narrowing towards the pointed apex, which is obtuse-angled (dorsal view) (Fig. 8).Paramerae moderately wide, narrowing towards the apices, with four setae each (Figs.7 and 8).Copulatory piece medium-sized, as long as around a half of aedeagus length, strongly chitinized, gutter-shaped, unifid, gradually narrowing apically, with a pointed apex.
Female genitalia unknown since no females were found.
Bionomy and distribution -The new species was found in the posterior part of the Ogorelička Pećina Cave, village of Sićevo, near Niš, Svrljiške Planine Mts., southeastern Serbia.It inhabits the channels belonging to the lower (pit) level of the cave and is a predator of cave-dwelling invertebrates.The upper level of the cave is inhabited by colonies of several bat species and its floor is covered by a great amount of guano deposits.This makes the upper cave level uninhabitable for the new trechine species and most troglobitic taxa.For the moment, the species is known only from the type locality.
Remarks -The new species belongs to the "winkleri" group based on the shape of the elytra, presence of unpronounced shoulders (rounded, not angled), absence of laid hairs on the vertex, presence of a longitudinal fissure on the fore tibias and the first elytral discal setae located above the level of the third humeral setae (Guéorguiev, 1971).Its type locality, the Ogorelička Pećina Cave, is inhabited by an additional 10 arthropod species and four bat species (Nešić et al., 2008).Among the arthropods, one species was recently described-a cave-dwelling pseudoscorpion Roncus crnobog B. Ćurčić, 2013 (Ćurčić et al., 2013).

CONCLUSIONS
The two new troglobitic trechine ground beetle species probably belong to old phyletic lineages of Tertiary or even pre-Tertiary origin (Guéorguiev, 1977).They are both relicts and endemics of the Carpatho-Balkan mountain system in eastern and southeastern Serbia.The endemic differentiation of the new species and the related 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 suit-able for preservation of the old and autochthonous fauna.