Duvalius, Delarouzee, 1859

Maghradze, Eter, Barjadze, Shalva, Lohaj, Roman & Faille, Arnaud, 2025, Two new Trechini (Coleoptera: Carabidae) from Georgian caves, Caucasus, Zootaxa 5609 (1), pp. 83-96 : 93-94

Key to the Caucasian species of the genus Duvalius

Note: This key is modified from Belousov (1991).

1. Eyes strongly reduced, depigmented...................................................................... 2

− Eyes well developed, pigmented........................................................................ 11

2. Larger species, BL 7.2–7.5 mm. Colour reddish-brown, head slightly longer than wide, antennae long, stretching backward reaching middle of elytra. Georgia, Abkhazeti region, Souvenir Cave...... D. iljukhini (Dolzhanski & Ljovuschkin, 1985)

− Smaller species, BL not exceeding 6.8 mm ................................................................. 3

3. Pigmented, dark, reddish-brown species................................................................... 4

− Depigmented, pale, testaceous species..................................................................... 5

4. Pronotum cordate, longer than wide, as long as head. Elytra wider, with maximum width in their middle. Longer antennae, extending backwards beyond the middle of the elytra. BL 6.0 mm, Georgia, Abkhazeti region, Arabika massif, Trechus’ Cave............................................................................ D. sokolovi Ljovuschkin, 1963

− Pronotum trapezoid, slightly wider than long; Head longer, ca 1.3 times longer than pronotum. Elytra elongated, with maximum width before the middle of elytral length. Antennae shorter, stretching backwards to the middle of the elytra; 4.97–5.8 mm. Georgia, Racha-Lechkhumi and Kvemo Svaneti region, Kvedi II Cave.............................. D. gregoi sp. nov.

5. Smaller species, BL 3.0– 4.7 mm ......................................................................... 6

− Larger species, BL 4.9–6.8 mm .......................................................................... 8

6. Shoulders distinct and prominent. In lateral view, the median lobe of the aedeagus is wider and distinctly rounded. BL 3.8–3.9 mm. Armenia, Stepanavan, Medved Gora............................ D. stepanavanensis lablokoff-Khnzorian, 1963

− Shoulders broadly rounded. Median lobe of aedeagus in lateral view strongly elongated, narrow, slightly rounded......... 7

7. Smaller species, BL 3.0– 3.7 mm. Broader, rounded head. Azerbaidjan, Nakhichevan, Mount Ilandagh................................................................................................. D. antoniae (Reitter, 1892)

− Larger species, BL 4.4–4.7 mm. Head narrow, almost parallel-sided. Azerbaijan, Zakatali, Agkemal.................................................................................................... D. martensi Casale, 1983

8. Elytra narrower, almost parallel-sided, anterior angles of pronotum distinct, prominent, head wider, rounded. 4.9–5.2 mm. East Turkey, Çifteköprü Pass between Hopa and Borçka................................ D. armeniacus Casale, 1979

− Elytra oval, distinctly narrowed posteriorly, anterior angles of pronotum not prominent, head narrower................. 9

9. Smaller species, BL 4.9–5.5 mm. Pronotum distinctly wider than long, elytra widest before the middle of their length. Central Caucasus, Samegrelo-Zemo Svaneti region, Kvira Mountain ............................... D. megrel Belousov, 1991

− Larger species, BL 5.6–6.6 mm. Pronotum narrower, almost as long as wide, elytra widest behind the middle of their length. .................................................................................................. 10

10. Elytral striae 1–3 well marked by punctured grooves, striae 4–7 only punctate, head narrower. Parameres with 3 apical setae. BL 6.6–6.8 mm. Georgia, Abkhazeti region, Arabika massif, Krubera-Voronya Cave................................................................................................... D. abyssimus Reboleira & Ortuño, 2014

− Elytral striae 1–4 well marked by punctured grooves, striae 5–7 only punctate, head wider. Parameres with 4–5 apical setae. BL 5.6–6.6 mm. Russia, Sochi, Baribana Cave........................... D. miroshnikovi Belousov & Zamotajlov, 1995

11. Eyes distinctly prominent, as long as temples. BL 6.5 mm. Armenia, Idjevan............................................................................................... D. yatsenkokhmelevskyi (lablokoff-Khnzorian, 1960)

− Eyes flat or only slightly prominent, shorter than temples..................................................... 12

12. All elytral striae deep, distinctly punctate. BL 5.8–5.9 mm. Russia, North Ossetia .............. D. gusevi Belousov, 1989

− Internal elytral striae distinctly marked and punctate, external striae indistinct, finely punctate....................... 13

13. Larger species, BL 6.0 mm., shoulders rounded. Eyes smaller, twice as short as temples. Median lobe of aedeagus almost straight, without basal bend, the apex strongly curved on the ventral side. Georgia, Samtskhe-Javakheti region, Baniskhevi valley......................................................................... D. kurnakovi Jeannel 1960

− Smaller species, BL 4.6–4.9 mm. Eyes larger, 1.5 times shorter than temples. Median lobe of aedeagus strongly bent. Azerbaijan, Vartachen area, Chalchalčaj.................................................... D. vartashensis Belousov, 1989