Key to the subgenus Bolbelasmus species from the western Palaearctic Region

(modified from Hillert et al. 2016)

1. Posterior margin of pronotum incompletely bordered, interrupted laterally of scutellum. …........................... 2

- Posterior margin of pronotum completely bordered. …........................................................ 6

2. Lateral margin of pronotum nearly semicircular between anterior angles and midline in dorsal view, anterior angles almost rounded; frontal horn and medial hornlike apophysis of pronotum distinct; scutellum triangular, approximately as long as wide; body length 11.0– 13.5 mm; southern parts of central Europe, France (Alsace), Italy, Balkan Peninsula, Poland, Russia and Ukraine; Asian part of Turkey ...................................... … B. (B.) unicornis (Schrank von Paula, 1789)

- Lateral margin of pronotum broadly rounded, regularly bent from anterior angle to middle, anterior corners of pronotum distinctly acuminate, lateral margin straight in front of anterior angles; frontal horn and medial hornlike apophysis of pronotum always indistinct; scutellum triangular, longer than wide; body length 9.5–12.0 mm; Cyprus, Greece (Rhodes), Iran, Iraq, Syria and Turkey. …....................................................................................... 3

3. Eye cantus weakly acuminate and distinctly exceeding eye laterally; scutellum rounded apically; Asian part of Turkey. ….............................................................................. B. (B.) tauricus Petrovitz, 1973

- Eye cantus regularly rounded and not exceeding eye laterally; scutellum acuminate apically. …....................... 4

4. Frontal horn weakly spaced from fronto-clypeal carina (viewed from above), pronotal punctation double and dense, small punctures sparser; frontal horn directed upwards to weakly backwards (Figs. 3A, 3 C–D, 4A–B, 4D).................… 5

- Frontal horn close to fronto-clypeal carina (viewed from above); pronotal punctation double and dense, small punctures denser; frontal horn directed obliquely forewards (Figs. 3B, 4C); aedeagus as in Fig. 5B; Cyprus ..... B. (B.) makrisi Miessen, 2011

5. Border of posterior margin of pronotum weakly interrupted laterobasally, but with only several single punctures; frontal horn directed weakly backwards (Figs. 3 C–D, 4D); aedeagus as in Fig. 5C; Greece (Rhodes), Iraq, Syria and Asian part of Turkey ............................................................................… B. (B.) nireus (Reitter, 1895)

- Border of posterior margin of pronotum distinctly interrupted laterobasally, single punctures absent; frontal horn directed upwardly (Figs. 3A, 4 A–B); aedeagus as in Fig. 5A; Iran ..................................................................................................... …. B. (B.) zagrosensis Sommer, Hillert, Hrůzová & Král, new species

6. Scutellum impunctate or finely, shallowly punctate; frontal horn simple or furcate apically. …........................ 7

- Scutellum densely punctate; apex of frontal horn simple..................................................... 11

7. Frontal horn simple; genae evenly rounded; oblique keel above eye longer than length of eye; head strongly constricted behind eye. ….............................................................................................. 8

- Frontal horn furcate apically; genae more or less angulate anterolaterally; oblique keel above eye reaching to anterior part of eye; head not strongly constricted behind eye. …............................................................ 9

8. Body surface blackish; pronotal punctation dense and distinct, separated by distance of 1–2 punctures combined; Algeria, Italy (Sicily) and Tunisia. …................................................ B. (B.) vaulogeri (Abeille de Perrin, 1898)

- Body surface brownish; pronotal punctation sparse but distinct, separated by distance of 3–4 punctures combined; Greece (Crete, Kasos). …....................................................... B. (B.) keithi Miessen & Trichas, 2011

9. Frontal horn short (not longer than wide), apex of horn approximately as wide as base of horn; pronotal punctation denser with exception of basal part, puncture separated by diameter of puncture; pronotal base with fine and regularly spaced punctures, puctures in shape of pinned points; elytral striae well impressed, completely developed; elytral intervals moderately convex; Spain. …............................................................... B. (B.) brancoi Hillert & Král, 2016

- Frontal horn long (longer than wide), tapering apically; pronotal punctation sparser, puncture separated approximately by three their diameters; pronotal base with fine, poorly visible and well separated punctures, punctures in shape of pinned points; elytral striae not impressed, punctures in row visible; elytral intervals flat; northern Africa. …............................. 10

10. Frontal horn parallel to anterior part of eyes; horn sharply keeled at basal half; middle hornlike apophysis of pronotum directed upwards, subapical protrusion situated basally; lateral hornlike apophyses of pronotum directed forwards; Algeria and Morocco. ….................................................................. B. (B.) bocchus (Erichson, 1841)

- Base of frontal horn parallel to level of posterior part of eyes; horn broadly keeled apically; middle hornlike apophysis of pronotum directed obliquely, subapical protrusion situated at apex; lateral hornlike apophyses of pronotum directed forwardly; Egypt, Libya and Tunisia .................................. … B. (B.) nikolajevi Hillert, Arnone, Král & Massa, 2016

11. Apex of frontal horn tapering apically, acute, weakly flattened in anterior part of horn; Spain and Gibraltar ................................................................................... … B. (B.) howdeni Hillert & Král, 2016

- Apex of frontal horn roughly as wide as base, apex broadly acute, strongly flattened in anterior part of horn; France (including Corsica), Portugal and Spain ................................................. … B. (B.) gallicus (Mulsant, 1842)