Key to the taxa of the genus Proleonhardella Jeannel, 1910

(modified after Jeannel 1924) (Figs 9–10)

1. Body more elongate, elliptical. Pronotum as wide as elytra, well constricted basally. Pronotal lateral margins well-rounded backwards. Mesosternal carina very low. Elytral punctuation rough and deep (subgenus Pholeuonillus Breit, 1913). Endogean, Mt Treskavica, southern Bosnia and Herzegovina ....................................................................... P. (Pholeuonillus) adolfi (Reitter, 1911)

– Body less elongate, oval. Pronotum narrower than elytra, weakly constricted basally. Pronotal lateral margins weakly rounded backwards. Elytral punctuation fine. Mesosternal carina elevated, angled (subgenus Proleonhardella Jeannel, 1910) ....................................................................................... 2

2. Elytra shorter, more convex, less than twice as long as pronotum (Fig. 10A) ................................. 3

– Elytra longer, less convex, more than twice as long as pronotum (Fig. 10B) .................................. 6

3. Body of oval shape, longer (TL 1.8–2.2 mm). Antennae short, not reaching middle of body. Antennomere III not longer than antennomere V. Antennomere VIII globular in males (Fig. 10C). Cavernicolous, Mts Bjelašnica and Igman, central Bosnia and Herzegovina [ P. (Proleonhardella) matzenaueri (Apfelbeck, 1907)] ....................................................................................................... 4

– Body of subglobular shape, shorter (TL less than 1.8 mm). Antennae long, reaching middle of body. Antennomere III longer than antennomere V. Antennomere VIII slightly elongate in males (Fig. 10D) ......................................................................................................................................... 5

4. Body of almost regular oval shape, longer (TL 2.0– 2.2 mm). Elytra not widened towards middle. Cavernicolous, Mt Bjelašnica, central Bosnia and Herzegovina ........................................................ ................................................. P. (Proleonhardella) matzenaueri matzenaueri (Apfelbeck, 1907)

– Body narrower anteriorly, shorter (TL 1.8–2.0 mm). Elytra clearly widened medially. Cavernicolous, Mt Igman, central Bosnia and Herzegovina ....................................................................................... ................................................................... P. (Proleonhardella) matzenaueri ottonis Müller, 1917

5. Body more elongate and convex, longer (TL 1.5 mm). Elytral punctuation finer and denser.Antennae shorter, with apical antennomeres thicker. Antennomere VIII barely longer than wide, antennomere IX as long as wide and antennomere X transverse in females. Cavernicolous, Mt Treskavica, southern Bosnia and Herzegovina ............................................ P. (Proleonhardella) leonhardi (Breit, 1913)

– Body less elongate and convex, shorter (TL 1.3 mm). Elytral punctuation stronger and less dense. Antennae longer, with apical antennomeres less thick. Antennomeres VIII, IX and X longer than wide in females. Cavernicolous, village of Trnovo, vicinity of the city of Sarajevo, central Bosnia and Herzegovina ...................................................... P. (Proleonhardella) apfelbecki Jeannel, 1924

6. Body longer (TL 3.0– 3.5 mm). Cavernicolous, Kamena Gora and vicinity of the towns of Prijepolje, Priboj and Pljevlja, southwestern Serbia and northern Montenegro .................................................. .......................................................................................... P. (Proleonhardella) remyi Jeannel, 1934

– Body shorter (TL less than 2.435 mm) ............................................................................................. 7

7. Elytra parallel in basal half (Fig. 10E) .............................................................................................. 8

– Elytra narrowed in basal half (Fig. 10F) ........................................................................................... 9

8. Pubescence long. Punctuation less fine. Apical antennomeres more widened. Pronotum less rounded. Apex of median lobe of aedeagus less bent ventrally. Elytral apex wide, obtuse and oblique. Cavernicolous, vicinity of the towns of Prijepolje and Priboj (southwestern Serbia) and Pljevlja (northern Montenegro) .................................................. P. (Proleonhardella) hirtella Jeannel, 1934

– Pubescence short. Punctuation finer. Apical antennomeres less widened. Pronotum more rounded. Apex of median lobe of aedeagus more bent ventrally. Elytral apex attenuated. Cavernicolous, Mt Sjemeć, eastern Bosnia and Herzegovina ......... P. (Proleonhardella) weiratheri (Reitter, 1913)

9. A1/A2 M 0.80. Mesosternal carina almost right-angled. Elytral lateral margins below humeral angles clearly sinuate. Maximum width of elytra prior to middle. Cavernicolous, village of Podromanija, near the town of Sokolac, eastern Bosnia and Herzegovina ............................................................... .......................................................................... P. (Proleonhardella) neumanni (Apfelbeck, 1901)

– A1/A2 M 0.76. Mesosternal carina obtuse-angled. Elytral lateral margins below humeral angles sub-parallel. Maximum width of elytra slightly after basal third. Cavernicolous, Mt Tara, western Serbia .................................................... P. (Proleonhardella) tarensis Ćurčić & Pavićević sp. nov.