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 : 257-258

Subgenus Lyrothorax Chaudoir, 1838

Type species: Feronia caspia Ménétriés, 1832 , by monotypy.

Recognition of the P. caspius complex. Body subconvex ( Figs 1 , 2 ), medium sized (10–16 mm); pronotum lyreshaped ( Fig 2 ); dorsal and ventral side and appendages mostly black, sometimes brown, males slightly shiny, females dull. Strongly brachypterous, hind wings reduced to small scales of about length of antennomeres 2 and 3 together. Suture of elytra not fused. Appendages robust.

Head subparallel; frontal impressions superficial; eyes small but convex; tempora about straight, about half as long as eye diameter, seen dorsally; mandibles robust; antennae short, reaching base of elytra; antennomere 1 robust, about as long as antennomere 3; base of antennomere 3 slightly depressed; antennomere 1 with one seta dorsally, antennomere 2 with one seta ventrally, antennomere 3 with a few apical setae; palpi long; ultimate labial palpomere fusiform; submentum with an anterior ridge, with two setae on each side. Microsculpture consisting of suppressed irregular meshes and micropores.

Pronotum transverse, sides converging to base; with two setigerous pores, one pore in hind angle and one distinctly before middle; median line fine, reaching base; fore angles rounded, apical margin concavely excavated. Hind angles of pronotum right-angled, or weakly obtuse-angled and blunt at tip, or acute-angled and distinctly directed outwards.

Elytra ovoid-elongate, humeri rounded; with parascutellar stria and pore puncture; striae distinct; three setigerous pores in interval 3, first adjacent to 3nd stria, next two ones adjacent to 2nd stria (sometimes 2nd pore adjacent to 3nd stria); first pore situated at about one fifth from base, 2nd one just behind middle, 3rd one at about one fourth from apex. 7th interval with two small pores near apex. Series umbilicata with 15–20 punctures, which are more distant from each other in the middle.Apical plica of epipleura present. Sutural angle simple, apex regularly rounded in both sexes.

Ventral side. Proepisterna, lateral sides of mesosternum, ventrites 3–5 densely punctured, ventrite 6 and 7 less densely punctured; metepisternum slightly longer than wide; metacoxae with two setae; abdominal ventrites with a pair of paramedian setae. Males with two setigerous pores, females with four such pores at apical margin of ventrite 7.

Legs of normal condition for a Pterostichus ; male protarsomeres 1–3 strongly broadened, protarsomere 4 about as long as wide; mesofemora with three setae on hind margin; metafemora with two setae, onychium without setae ventrally.

Median lobe of aedeagus robust, middle part bent at an angle of about 90 degrees to basal part. Endophallus is dorso-apically directed, not provided with a sclerotized plate as in the Japanese species, although some specimens of P. caspius have some slight sclerotization on the same position, the gonopore piece is clearly longer, the preapical lobe is small, in all species is an ostium lobe present, the apical lobe is large, branched, one branch directed to the base and the branch in the basal part directed apically and in the apical part dorsally hooked, the median lobe of the endophallus as described by Sasakawa (2009) is in all species absent.

Composition. The P. caspius complex includes three Western Palaearctic species: P. caspius , P. fritzei sp. n. and P. vagus sp. n. The relationships of these species with Japanese species require special study (see Nemoto 1998; Sasakawa & Kubota 2007; Sasakawa 2009). It is worth noting that in the Japanese species the endophallus is elongated dorsally, with the distal half distinctly turned to the left; the gonopore opening is oriented anteroventrally to anteriorly. Some Japanese species have no ostium lobe, other species have a median lobe of the endophallus ( Sasakawa & Kubota 2007; Sasakawa 2009). Further studies including molecular research should clear up if there is really a close relationship of the Japanese species to the West Palaearctic Lyrothorax .

Distribution. Species of the P. caspius complex are flightless forest species associated mainly with Hyrcanian-type forests located in the Talysh region in Azerbaijan and in the provinces bordering the Caspian Sea in Iran. These forests are isolated by arid territories from the rest of Transcaucasia and Turkmenistan and by high mountain areas of the Elburz in Iran. In recent years one of the species ( P. vagus sp. n.) was introduced in the Czech Republic.

Remarks. In the P. caspius complex which members are all brachypterous, external characters such as shine on dorsum and features of pronotum vary widely between populations. We also assume that populations in the Czech Republic, representing an introduced species are based on few individuals, whereby founder effects could be expected. Certain specimens (especially females) of P. caspius and P. vagus sp. n. from Gilan and West Māzandarān are difficult to distinguish in some cases. For species identification, see identification key.

Old material from the P. caspius species group includes specimens from “Transkaspia, Saramsakli” (without collector name, but maybe collected by F. Hauser). The locality Saramsakli occurs in different entomological works; in most papers Saramsakli is situated in Turkmenistan, Majer (1988: 135) placed Saramsakli in Iran near Gorgan, but always as untraced, without an exact location. It is quite possible that “Saramsakli” means Saram sakli, where Saram is the name of the village in Māzandarān and sakli (from the Georgian სახლი [sakhli] “house, building”), the name of a stone structure of the inhabitants of the Caucasus and the Middle East. Thus we suppose that “Saramsakli” (= Saram) is located in Māzandarān (Estakhr-e Posht Rural District, Hezarjarib District, Neka County) with coordinates: 36°28′29″N 53°28′56″E, about 100 km west of Gorgan. The record of P. vagus sp. n. from “env. Kushka” in South East Turkmenistan is probably based on mislabelling (see below under this species). Therefore, the occurrence of species of the P. caspius complex in Turkmenistan requires confirmation.

Figures

FIGURE 1. Habitus of lectotype and paralectotypes of P. caspius (Ménétriés, 1832), with labels including the handwritten bottom label by Ménétriés. Scale bar =10 mm.

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.