Inotrechus usholtaensis Maghradze, Lohaj & Faille, 2025

Maghradze, Eter, Barjadze, Shalva, Lohaj, Roman & Faille, Arnaud, 2025, Two new Trechini (Coleoptera: Carabidae) from Georgian caves, Caucasus, Zootaxa 5609 (1), pp. 83-96 : 86-90

Inotrechus usholtaensis Maghradze, Lohaj & Faille sp. nov.

( Figs 3–6 , 11–13 )

Type material. Holotype male, labelled: “ GEORGIA, Racha-Lechkhumi and Kvemo Svaneti region, Racha karst massif, Usholta Cave , dark zone, 21.viii.2022, E. Maghradze leg.” ( IZISU).

Paratypes (21♂♂, 19♀♀): 1♂, 2♀♀: same data as holotype ( IZISU) ; 3♂♂, 2♀♀: same data as holotype, but 25.vii.2022, S. Barjadze leg. ( IZISU) ; 1♂, 1♀: same data as holotype, but 04.v.2023, E. Maghradze leg. ( IZISU) ; 6♂♂, 6♀♀: same data as holotype, but 23.vi.2023, E. Maghradze & A. Faille leg. (3♂♂, 3♀♀ - IZISU; 3♂♂, 3♀♀ - SMNS) ; 1♂, same data as holotype, with extraction code SMNS-L2354 ( SMNS) ; 1♀: same data as holotype, but 11.ix.2022, J. Grego lgt., with extraction code RL-89 ( CRL) . Spares in ethanol: 1♂ - EM68 (25.vii.2022, S. Barjadze leg. ( IZISU)) and 2♂♂, 1♀, E. Maghradze & A. Faille leg., 23.vi.2023 ( SMNS) .

Diagnosis. Medium-sized anophthalmous trechine beetle; body depigmented; coloration homogeneous, yellowish to light brown; body strongly flattened; microsculpture almost indistinct, except on the neck where a few transverse meshes can be distinguished. Head longer than wide; mandibles short and robust; frontal furrows complete; eyes reduced, without trace of ommatidia; submentum with 6 setae. Pronotum strongly cordate, wider than long. Elytra, and appendages elongate, narrow; elytral striae almost effaced; two discal setiferous pores and one preapical pore on each elytron. Abdominal ventrites mostly glabrous with a pair long paramedian and short irregulary sinuated setae around paramedian pair. Habitus as in Figs 3–6 .

Description. BL: 5.5–6.7 mm.

Head ( Figs 3–6 ): glabrous, longer than wide, longer and slightly narrower than pronotum, HL 1.21–2.4 mm, HW 0.96–1.24 mm, Index HL/HW 1.2–1.5. Temples convex, neck constriction distinct. Two pairs of supraorbital setae present, frontal furrows shallow, divergent anteriad, incomplete, reaching posterior frontal pore. Head with a strong depression behind the second supraorbital setae and reaching the base of the neck ( Figs 5–6 ). Eyes reduced to a small whitish area, without trace of ommatidia, two pairs of anterior supraocular setae ( Fig. 6 ). Clypeus quadrisetose; labrum concave, with six setae situated near the anterior margin, extreme ones being the longest and anterior lateral margins with 7–10 short setae. Mandibles short and robust, sharp; right mandible tridentate, left bidentate. Mentum bisetose, with a simple, protruding tooth; labial suture complete, not fused; submentum with 6 setae ( Fig. 5 ); maxillary palpi short, glabrous (some specimen with a tiny seta on palpomere II); labial palpi thin and long, glabrous except penultimate palpomere, which is bisetose. Antennae elongate, filiform, pubescent from antennomere II, scape with few setae; AL 4.5–5.4 mm, length of antennomeres (from scape to terminal segment, in mm): 1.00 / 0.78 / 1.50 / 1.47 / 1.5 / 1.39 / 1.33 / 1.22 / 1.17 / 1.06 / 1.19.

Pronotum: small and strongly cordate, slightly wider than long, PL 0.86–1.11 mm., PW 1.05–1.27 mm, Index PL/PW 0.71–0.9, with narrow protruding base, lateral margins strongly sinuate before hind angles, widest at anterior fourth. Pronotal base deeply foveolate near posterior angles, narrowed, the basal margin much shorter than the anterior; hind angles distinct, prominent, strongly and upwardly protruding; anterior angles widely rounded. Two pairs of long and thick pronotal setae present, antero-lateral pair situated in anterior sixth of pronotal length, basolateral setae near posterior angles ( Fig. 3 ).

Elytra ( Fig. 3 ): long and narrow, gradually widened towards apex, EL 3.1–3.6 mm, EW 1.85–2.24 mm, index EL/EW 1.55–1.69. Humeri rounded; elytral striae almost effaced, barely visible. Elytra slightly convex, with flattened disc. Scutellar striola absent, parascutellar seta present. Elytra with two pairs of long and thick discal and one similar preapical setiferous pore, preapical pair located near elytral base in stria 3, discal pores situated in the anterior half of elytral length of stria 2 and 3. Humeral group of umbilicate series aggregated, pores 1–4 slightly separated from marginal gutter; pore 2 equidistant from pores 1 and 3, distance between pores 2 and 3 longer than between pores 3 and 4.

Legs: Long and slender; protibiae without sulcus on dorsal side, antennal cleaning organ well developed; first two tarsomeres of male protarsi dilated at internal margins; tarsi pubescent, claws long and acute.

Abdominal ventrites ( Fig. 4 ): mostly glabrous, central part with a few (6–19) irregularly situated short, and a pair of long paramedian setae; last ventrite for both sexes with two pairs of setae, one pair longer and one relatively shorter, the difference between female and male is the arrangement of setae, for female they make transverse row (anterior is longer), male setae are longitudinal (posterior is longer).

Male genitalia: median lobe of aedeagus relatively narrow in lateral view, wide at base, broadly curved; apical part gradually curved upward, elongate, with an upturned apex ( Figs 11–12 ). Internal sac (endophallus) armature poorly sclerotized, paired and symmetrical, covered with a broad field of uniformly sized microtrichia, very similar to that of allied taxa. Parameres with four long, straight apical setae each.

Female genitalia: gonocoxite II triangular, distinctly sclerotized, slightly longer than wide, with 4 ensiform spines on the dorsal and lateral surface and small apical groove that harbours two short nematiform setae; gonocoxite I simple, wide, slightly sclerotized, with 4 to 5 long setae on the inner margin and 2 to 4 relatively short randomly distributed setae, on ventral projection; laterotergite less sclerotized with 13– to 15 setae on the inner margin and 10– to 16 on the basal half ( Fig. 14 ).

Differential diagnosis. Inotrechus usholtaensis sp. nov. differs from the other two Inotrechus species (see Identification Key) by the following combination of characters:

a) submentum with 6 setae in the new species, whereas 8 in I. injaevae and I. kurnakovi ;

b) head large, rounded in the new species, whereas narrow and relatively long in I. injaevae and I. kurnakovi ;

c) mandibles short and robust in the new species, while I. injaevae and I. kurnakovi have long and slender mandibles;

d) reduced eyes in the new species, with a small whitish area on top and no trace of ommatidia, similar to I. kurnakovi , whereas I. injaevae has reduced eyes with a short black line and no ommatidia;

e) pronotum distinctly wider than long in the new species and I. injaevae , while, in I. kurnakovi , it is almost as long as wide;

f) elytral striae barely visible, indistinct in the new species, while clearly visible in I. injaevae and I. kurnakovi .

Etymology. Named after the type locality, Usholta Cave.

Distribution. So far, the species is only known from its type locality, Usholta Cave in the Racha karst massif, Racha-Lechkhumi and Kvemo Svaneti regions, Western Georgia ( Map 1 ). Caves in this area are poorly sampled, and I. usholtaensis sp. nov. may be found in additional localities in the future.

Ecology. The species is troglobitic and found throughout the cave, typically near the subterranean river on gravel banks, wood debris brought from outside (incl. rests of old wooden ladder), or under stones. The fauna of Usholta Cave is poorly studied, with only seven species recorded to date: Triphosa dubitata (Linnaeus, 1758) (moth), Acanthophorella valerii Antić, 2023 (millipede), Deuteraphorura sp. and Plutomurus weinerae Barjadze, Kováč & Parimuchová, 2024 (springtail), Rilaena zakatalica Snegovaya & Chemeris, 2005 (harvestman), Neobisium cf. verae (Lapschoff, 1940) (pseudoscorpion), and Laemostenus (Antisphodroides) ljovushkini Vereschagina, 1985 (carabid beetle) ( Barjadze et al. 2015, 2024; Antić et al. 2023).

Based on above mentioned differences, all three representatives of the genus Inotrechus can be easily identified using the following key:

Figures

MAP 1. Distribution map of the Inotrechus and Duvalius species in Georgias. (1) D. abyssimus (Krubera-Voronya Cave); (2) D. gregoi sp. nov. (Kvedi II cave); (3) D. iljukhini (Souvenir Cave); (4) D. kurnakovi (Baniskhevi valley, Borjomi-Kharagauli National Park); (5) D. megrel (Samegrelo-Zemo Svaneti region, Kvira Mountain); (6) D. sokolovi (Trechus’ Cave); (7) I.injaevae (Sakishore Cave); (8) I. kurnakovi (Prometheus and Melouri caves); (9) I. usholtaensis sp. nov. (Usholta Cave).

FIGURES 3–4. Inotrechus usholtaensis sp. nov. (3) Habitus of the holotype, dorsal view. (4) Habitus of a paratype, lateral view. Note: setae are marked with white dots.

FIGURES 5–6. Inotrechus usholtaensis sp. nov. (5) Head of a paratype, lateral view. Note: setae are marked with white dots. (6) Head and ocular area of the holotype, dorsal view.

FIGURES 7–12. Aedeagi of Inotrechus species. (7–8) I. kurnakovi: 7. Lateral view, 8. Dorsal view; (9–10) I. injaevae: 9. Lateral view, 10. Dorsal view; (11–12) I. usholtaensis sp. nov.: 11. Holotype, lateral view, 12. Paratype, dorsal view.

FIGURES 13–14. Female genitalia (13) Duvalius gregoi sp. nov.; (14) Inotrechus usholtaensis sp. nov. Gonocoxite II: 1— apical nematiform setae, 2—ensiform spines; gonocoxite I: 3—long setae on the inner margin, 4—short randomly distributed setae on the ventral projection; 5—laterotergite setae.