A new species of Leonhardia Reitter, 1901 (Coleoptera, Leiodidae, Leptodirini) from Bosnia and Herzegovina, with a key to species of the genus

A new leptodirine leiodid beetle species belonging to the genus Leonhardia Reitter, 1901, L. solaki sp. nov., from a pit in Bosnia and Herzegovina (western Balkan Peninsula) is described and diagnosed. Important morphological features of the new species are listed and photographed. The new species is endemic to the Dinarides of Bosnia and Herzegovina. A key for identification of species and subspecies of the genus Leonhardia is also provided.


Introduction
The genus Leonhardia Reitter, 1901 (Coleoptera, Leiodidae, Leptodirini) contains the following six species: Leonhardia delminiumica Nonveiller, Pavićević, Rađa & Vujčić-Karlo, 2002 (from the Jama na Paklinama Pit and the Parampatuša Cave, comparison. For that purpose, we used a Stemi 2000 binocular stereomicroscope (Carl Zeiss, Jena, Germany), a SMZ 18 binocular stereomicroscope (Nikon, Tokyo, Japan) with a DS-Fi1c digital camera (Nikon, Tokyo, Japan) attached, and an Axioskop 40 light microscope (Carl Zeiss, Jena, Germany). Beetles were additionally illuminated under binocular stereomicroscopes by an Intralux 5100 cold light source (Volpi, Schlieren, Switzerland). Detailed morphology of the new species was observed using a Tescan Mira 3 XMU field emission scanning electron microscope (FESEM) (Tescan, Brno, Czech Republic) at the Faculty of Technology and Metallurgy, University of Belgrade. Before analysis, the samples were coated with gold for 45 s using a Polaron SC502 Sputter Coater (Fisons, VG Microtech, East Sussex, England). The high-vacuum mode was used at an acceleration voltage of 10 kV. The index of electron beam intensity was 8.00. The electron beam current was 364 μA, while pressure in the column was around 1.3e -3 Pa.

AL
total antennal length including the scape; A1L/A2L ratio of length of antennomere I to length of antennomere II; A2L/A3L+A4L ratio of length of antennomere II to length of antennomeres III and IV combined; A8L/A8W ratio of length of antennomere VIII to width of antennomere VIII; A9L/A9W ratio of length of antennomere IX to width of antennomere IX; A10L/A10W ratio of length of antennomere X to width of antennomere X; A11L/A11W ratio of length of antennomere XI to width of antennomere XI; EL/EW ratio of elytral length (as the linear distance measured along the suture from the elytral base to the apex) to maximum elytral width; HL/HW ratio of head length to maximum head width; M mean value for certain measurements; PB/AM ratio of pronotal base length to anterior pronotal margin length; PB/EB ratio of pronotal base length to elytral base length; PL/PW ratio of pronotal length to maximum pronotal width (as the greatest transverse distance); R range of total measurements performed; TL total body length (measured from the anterior margin of the clypeus to the elytral apex).  (Jeannel 1924;Nonveiller et al. 2002;Ćurčić et al. 2014.
Leonhardia solaki sp. nov. is easily distinguished from L. reitteri, from which it differs with respect to AL (antennae exceeding the middle of elytra in males and reaching the middle of elytra in females vs. antennae barely reaching the middle of body); A2L/ A3L+A4L (antennomere II shorter than the following two antennomeres combined vs.  antennomere II as long as the following two antennomeres combined); A8L/A8W (M in males 2.06, in females 1.58 vs. 1.50 in both genders); A10L/A10W (R in females 1.54-1.78 vs. more than 2.00 in both genders); shape of the hind pronotal angles (obtuse vs. right or weakly acute); shape of the mesosternal carina (almost right-angled, anterior margin convex, posterior margin regularly concave vs. obtuse-angled, anterior margin obtuse, posterior margin deeply incised); shape of elytra (inversely ovate vs. oval); shape of the median lobe in dorsal (wider in apical half, apically flattened vs. thinner in apical half, apically narrowed) and lateral (more elongate vs. less elongate) views; length of the median lobe (barely longer than parameres vs. markedly longer than parameres); and position of parameral setae in dorsal view (inner pre-apical seta somewhat separated from two remaining setae vs. all setae equidistant) (Figs 2-4) (Breit 1902;Jeannel 1924;Knirsch 1928;Müller 1937;Perreau 1999;Nonveiller et al. 2002).
Leonhardia solaki sp. nov. differs from L. delminiumica in regard to TL (R 3.40-3.65 mm in males, 3.55-3.93 mm in females vs. R 3.10-3.20 mm in males, 3.40 mm in a female); A8L/A8W (M 2.06 in males, 1.58 in females vs. antennomere VIII barely longer than broad); shape of the mesosternal carina (almost right-angled, posterior margin less concave vs. obtuse-angled, posterior margin more concave); shape of the median lobe in dorsal (apically flattened, with a rounded apex vs. apically narrowed, with a pointed apex) and lateral (more curved, wider vs. less curved, narrower) views; length of the median lobe (barely longer than parameres vs. markedly longer than parameres); size of the basal bulb in dorsal view (larger vs. smaller); and position of parameral setae in dorsal view (inner pre-apical seta closer to the two remaining setae vs. inner pre-apical seta farther away from the two remaining setae) (Figs 2-4) (Nonveiller et al. 2002).
Leonhardia solaki sp. nov. is easily distinguished from L. jajcensis, from which it differs with respect to AL in females (antennae reaching the middle of elytra vs. antennae ending before the middle of elytra); shape of the hind pronotal angles (obtuse vs. almost right); shape of the mesosternal carina (higher, anterior margin more convex, posterior margin more concave vs. lower, anterior margin less convex, posterior margin less concave); form of the elytra (more elongate vs. less elongate); shape of the median lobe in dorsal (apically flattened vs. apically narrowed) and lateral (more thickened in its basal half, less convex ventrally vs. less thickened in its basal half, more convex ventrally) views; length of the median lobe (barely longer than parameres vs. markedly longer than parameres); size of the basal bulb in dorsal view (larger vs. smaller); and position of parameral setae in dorsal view (inner pre-apical seta farther away from the two remaining setae vs. inner pre-apical seta closer to the two remaining setae) (Figs 2-4) (Ćurčić et al. 2014).
Leonhardia solaki sp. nov. differs from L. sebesicensis in regard to AL in females (antennae reaching the middle of elytra vs. antennae ending before the middle of elytra); shape of the hind pronotal angles (obtuse-angled in both genders vs. almost rightangled in males); shape of the pronotum and elytra (less elongate vs. more elongate); shape of the mesosternal carina (apically rounded vs. apically toothed); shape of the median lobe in dorsal (apically flattened vs. apically rounded) and lateral (more curved, narrower in apical half vs. less curved, wider in apical half ) views; length of the median Figure 3. SEM images of morphological features of Leonhardia solaki sp. nov. from the Golubnjača kod Skucana Pit, village of Skucani, close to the town of Glamoč, western Bosnia and Herzegovina A paratype male, habitus, dorsal aspect B paratype male, habitus, lateral aspect C paratype male, head, dorsal aspect D paratype male, microsculpture of head, dorsal aspect E paratype male, right antenna, dorsal aspect F paratype male, pronotum, dorsal aspect G paratype male, microsculpture of pronotum, dorsal aspect H paratype male, mesosternal carina, lateral aspect I paratype male, mesoventrite, ventral aspect J paratype male, scutellum, dorsal aspect K paratype male, elytra, dorsal aspect L paratype male, microsculpture of elytra, dorsal aspect. lobe (barely longer than parameres vs. markedly longer than parameres); and position of parameral setae in dorsal view (inner pre-apical seta somewhat separated from two remaining setae vs. all setae equidistant) (Figs 2-4) (Ćurčić et al. 2018).
Male genitalia: Aedeagus elongate, straight, thin, sclerotized (Figs 2C, D). Basal bulb small and rounded in dorsal view (Fig. 2C), moderately large in lateral view (Fig. 2D). Median lobe in dorsal view sub-parallel, rounded anteriorly, with a flattened apex, longer than parameres (Fig. 2C). Median lobe in lateral view curved, straight in basal half, sub-apically concave dorsally, almost straight ventrally in basal part, with an acute apex curved downwards (Fig. 2D). Parameres slender, narrow, arcuate, subapically curved towards exterior, each with a dilated rounded apex in dorsal view (Figs 2C, E), while gently narrowing distally in lateral view (Fig. 2D). Paramere bearing three setae: two strong, long, in apical and pre-apical position, respectively, and one inner, thin, short, in pre-apical position (Fig. 2E). Two long parameral setae close-set, short one somewhat separated, positioned somewhat below level of other two parameral setae (Fig. 2E). Endophallus elongate, tubular. Copulatory piece having a Y-shaped phanera and two lateral basal sclerifications, in front of which a weakly chitinized structure resembling teeth is present. In addition, two lateral bands are present in apical half of median lobe (Fig. 2C).
Female abdominal sternite VIII: Large, transverse, with a thin anterior process, carrying pubescence (Fig. 2H). Intraspecific variability. A certain level of intraspecific variability is observed in the new species. Several morphological differences between males and females point to the occurrence of sexual dimorphism. To be specific: (i) males are on average slightly shorter than females; (ii) the antennae in males are longer than in females; (iii) antennomeres VIII-XI in males are more slender than in females; (iv) the head in males is larger than in females; (v) the pronotum in males is more elongate than in females; (vi) the elytra in males are more elongate than in females.
Geographic distribution. Thus far, the species is known only from its type locality -the Golubnjača kod Skucana Pit, situated in the village of Skucani, close to the town of Glamoč in western Bosnia and Herzegovina. This site represents the westernmost location of a Leonhardia species. We assume that the new species probably inhabits other subterranean sites in the surrounding areas of western Bosnia and Herzegovina, although one of us (TR) visited the Ledenjača Cave situated in the same village (Skucani), but found no specimens of the new species there.
Bionomy and habitat. All specimens of L. solaki sp. nov. were collected deep in the Golubnjača kod Skucana Pit. They were recorded at this subterranean site at a depth of 30 m under conditions of permanent darkness and high humidity, along with the presence of trickling water. All individuals of L. solaki sp. nov. were gathered manually from the floor and walls in the innermost part of the pit. Aside from the new species, Golubnjača kod Skucana Pit is inhabited by another subterranean leiodid, Parapropus ganglbaueri obenbergeri Mařan, 1943, which is recorded in the same habitat where individuals of the new species were found, so these two taxa can be treated as sympatric. The same pit is also the type locality of the recently described moth fly Psychoda glamocensis Wagner &Rada, 2020 (Wagner andRada 2020). (Figs 2-4) 1

Discussion
In the chapter on the family Leiodidae of the recent Catalogue of Palaearctic Coleoptera, Perreau (2015) mentioned L. delminiumica as an endemic of Mt. Pakljina Planina, but in fact the correct name of the mountain is Mt. Pakline. Furthermore, Perreau (2000Perreau ( , 2015 reported that L. droveniki inhabits Ilidža (without any additional data, this location refers to a municipality of the city of Sarajevo), but the given species lives in a cave on Mt. Kruščica, in the environs of the town of Vitez. Knirsch (1928) erroneously indicated several type localities of certain Leonhardia species collected by the speleologist Leo Weirather (Innsbruck, Austria). Weirather relied on the sale of beetle specimens to fund his research and tried to protect his discoveries from competition by hiding his collecting locations under assumed names and code numbers. Weirather's diaries were recently published by Giachino and Lana (2005) and Hauser (2011). Subsequently, Pretner (2011) decoded a list of caves and above-ground collecting sites visited by Weirather. As for Weirather's material of Leonhardia, the type locality of L. hilfi robusta is the Vuk Pit situated on Vilinac in the northern part of Mt. Čvrsnica [not soil from the Strmenica site on Mt. Plasa, as first stated by Knirsch (1928) and later followed by Perreau (2000Perreau ( , 2015 and Ćurčić et al. (2014)], a situation that was later clarified by Pretner (2011). Additionally, Knirsch (1928) stated that the type locality of L. reitteri mersa is Vrbanje in the environs of Banja Luka (in fact the settlement of Vrbanja is located within the city limits of Banja Luka). As was later indicated by Müller (1937) and Pretner (2011), the correct name of this type locality is the Pećina pod Orlovcem Cave in the village of Korićani on the northern slope of Mt. Vlašić. Perreau (2000) and Ćurčić et al. (2014) indicated that an unnamed ice cave at the Harambašina Voda site on Mt. Vlašić is the type locality of L. reitteri reitteri (in fact this site is the type locality of L. reitteri retusa Knirsch, 1924, a synonym of L. reitteri reitteri). However, this location [initially mentioned by Breit (1902) as an unnamed cave from the northern mountains of Bosnia] should correctly be referred to as an unnamed ice cave south of the town of Žepče, as was first stated by Reitter (1902) and later confirmed by Jeannel (1924) and Pretner (2011). Jeannel (1910) placed the genus Leonhardia in the "Apholeuonus" phyletic series, which was later followed by Jeannel (1924) and Perreau (2000). This series is characterized by the great variety of genera belonging to the group, with form of the body varying from globular and vesicular to narrow and elongate (Jeannel 1924). The body pubescence is scattered, erect, and short, each hair placed at the bottom of a large puncture. Combs on the fore tibias are reduced and the femora are narrowed in the apical third in most cases. Armature of the endophallus includes one ventral Y-shaped piece, two dorsal parts, and two lateral parts. Dorsal parts of the armature of the endophallus are fused along the median line and constitute a tooth that is apically pointed in the genera Leonhardia, Adelopidius Apfelbeck, 1907, and Apholeuonus Reitter, 1889, suggesting that the mentioned genera are closely related (Jeannel 1924).
The leiodid tribe Leptodirini is one of the largest and most diverse groups of subterranean insects (Ribera et al. 2010). Their distribution is restricted to the Palaearctic region, with the variety of forms being highest in the Mediterranean (Perreau 2000(Perreau , 2005. Both morphological and molecular studies have been applied in order to determine phylogeny of the tribe (Perreau and Pavićević 2008b;Ribera et al. 2010;Fresneda et al. 2011;Njunjić et al. 2017Njunjić et al. , 2018Antunes-Carvalho et al. 2019;Perreau 2019). Molecular phylogenetic studies treating the western Mediterranean (both Sardinian and Pyrenean) Leptodirini were initially conducted on the Sardinian taxa (Sbordoni 1980;Caccone and Sbordoni 2001). They were followed by analysis of the Pyrenean fauna (Ribera et al. 2010), which indicated that the principal Pyrenean subterranean lineages were split out prior to the Early Oligocene (Ribera et al. 2010). With 36 genera and 103 species inhabiting subterranean habitats, Leptodirina is one of the most diverse subtribes of the tribe Leptodirini (Njunjić et al. 2017). In regard to Dinaric representatives of the subtribe Leptodirina, studies devoted to the phylogeny of individual taxa or the entire group are very few, being either morphology-based (Perreau and Pavićević 2008a) or molecular-based (Njunjić et al. 2017(Njunjić et al. , 2018. Perreau and Pavićević (2008b) stated that the monophyly of Leptodirina is very questionable because a number of taxa are highly troglobiomorphic and because numerous morphological features are potentially homoplasic. Njunjić et al. (2018) maintained that the subtribe is in fact polyphyletic inasmuch as three genera of Leptodirina (Charonites Apfelbeck, 1907, Apholeuonus, and Parapropus Ganglbauer, 1899) constitute a well-supported clade, which represents a sister clade in relation to other Leptodirini, while two genera of the same subtribe (Remyella Jeannel, 1931 andRozajella S. Ćurčić, Brajković &B. Ćurčić, 2007) form a clade with Bathysciina+Bathysciotina, which is weakly supported in both molecular and morphological terms (Njunjić et al. 2018). It was estimated that the latter clade was formed about 32 million years ago, during the Early Oligocene, while the one which includes the genera Charonites, Apholeuonus, and Parapropus originated more recently (about 25 million years ago), during the Late Oligocene (Njunjić et al. 2018). According to this and on the basis of morphological similarities between those three genera and Leonhardia, we suggest that the latter genus originated during the Late Oligocene too. The subtribal assignation of Remyella, Rozajella and Nonveilleriella Perreau & Pavićević, 2008 is questionable and should be reassessed (Njunjić et al. 2017(Njunjić et al. , 2018. To clarify the phylogenetic status of the subtribe Leptodirina as a whole and of its genera, it is essential to study as many genera as possible in this manner. The differentiation of L. solaki sp. nov. and other species of Leonhardia in a limited part of the Balkan Peninsula was brought about by the Alpine Orogeny, successive evolution of the subterranean karstic relief in the Cenozoic, and specific palaeoclimatic events in the Neogene. These processes enabled the creation of a number of new epigean and hypogean habitats suitable for conservation of the old native Aegean fauna (Ćurčić et al. 2015). Finding of the new hypogean leiodid species described and diagnosed herein calls attention to the fact that the Dinarides represent a remarkable hotspot of subterranean biodiversity. Multiple colonization of subterranean niches of the Dinarides by different lineages of beetles in different chronological phases during the Tertiary was possible (Casale et al. 2004). It is apparent that the great number of endemics occurring in the Dinarides is related to the fragmentation of hypogean environments, which promoted the evolutionary drift in isolated populations allowed by the long-term persistence and higher stability of subterranean habitats compared to epigean ones (Gibert and Deharveng 2002). During cool and dry phases of the Pleistocene, subterranean sites (caves, pits, and the fissure network in bedrock) on the Balkan Peninsula might have become fewer and separated from each other, thereby enabling allopatric speciation of subterranean leptodirine leiodid beetles influenced by vicariant range fragmentation (Polak et al. 2016).