Lyrothorax, Chaudoir, 1838

Muilwijk, Jan, Kataev, Boris M. & Wrase, David W., 2024, Review of the subgenus Lyrothorax of the genus Pterostichus (Coleoptera: Carabidae) in the Western Palaearctic, with descriptions of two new species, Zootaxa 5468 (2), pp. 255-274 : 273

Key to Western Palaearctic Lyrothorax species based on habitus

Because of variation between populations all characteristics must be taken into account.

1 Specimens from Czech Republic. Habitus as in Fig. 2c . Inner and outer basal foveae of pronotum joined, outer foveae normally separated from lateral margin by a long keel, inner foveae deep and long, longer than outer foveae. Hind angles of pronotum as a rule right-angled, or weakly obtuse-angled, blunt at tip. Pronotal sides converging towards base. Elytra and pronotum slightly shiny. Basal margin of elytra more or less angularly merging into lateral margin. Base of elytra more or less hooked towards lateral margins. BL: 10.0– 12.5 mm ............................................................ P. vagus sp. n.

- Specimens from Iran and Azerbaijan...................................................................... 2

2 Basal foveae of pronotum without punctures or only with fine punctures. Inner and outer basal foveae of pronotum joined, outer foveae normally separated from lateral margin by a long keel, inner foveae deep and long, longer than outer foveae. Pronotal hind angles as a rule right-angled, or weakly obtuse-angled, blunt at tip. Pronotal sides converging towards base ( Fig. 2c ). Elytra and pronotum slightly shiny. Basal margin of elytra more or less angularly merging into lateral margin. Punctation of metepisternum clearly less dense than that of metasternum, punctures even coarse ( Fig. 4c ). On average larger; specimens from Golestan clearly larger than specimens from Māzandarān. BL: 12.5–16.1 mm. Iran, Māzandarān and Golestan .................................................................................................... P. vagus sp. n.

- Basal foveae of pronotum with at least some distinct punctures. Inner foveae less deep, shorter ( Figs 2a, 2b ). Basal margin of elytra continuing fluently into lateral margin. On average smaller. BL: 10.5–14.9 mm ............................... 3

3 Pronotal hind angles as a rule right-angled. Pronotal sides converging towards base. Elytra in comparison more elongated, less convex, with inner intervals more convex ( Fig. 2a ). Head in comparison wide. Punctation on pronotum as a rule restricted to basal foveae. Punctation of metepisternum less coarse than that of metasternum ( Fig. 4a ). Azerbaijan and Iran (Ardebil, Gilan)................................................................................. P. caspius (Mén.)

- Pronotal hind angles as a rule acute-angled, distinctly directed outwards. Pronotal sides strongly converging towards base. Elytra in comparison more oval and more convex, with inner intervals flatter ( Fig. 2b ). Head in comparison less wide. Basal foveae of pronotum as a rule densely punctured, also between them with scattered punctures. Punctation of metepisternum even coarser than that of metasternum ( Fig. 4b ). Iran, from Gilan to East Golestan .......................... P. fritzei sp. n.

Figures

FIGURE 2. Habitus in dorsal view and pronotum increased, (a) P. caspius (Ménétriés, 1832) from Talysh, (b) P. fritzei sp. n. holotype, (c) P. vagus sp. n., from different localities, c1 holotype, c2 from Bylnice, Czech Republic. Scale bar =10 mm.

FIGURE 4. Metepisterna and metasternum, (a) P. caspius (Ménétriés, 1832) from Gilan, South Siahkal, (b) P. fritzei sp. n. holotype, (c) P. vagus sp. n. holotype. c1 holotype, c2 from Asålem Pass.