taxonID	type	description	language	source
8F2F2F2DA727FF9EFF1F4A163540FC32.taxon	description	urn: lsid: zoobank. org: act: B 690 DBEF- 51 BF- 449 A- 9 A 95 - F 4 F 91 CA 27 CD 6 Figs 2 – 6, Tables 1 – 3	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA727FF9EFF1F4A163540FC32.taxon	diagnosis	Diagnosis. Body length up to 1.5 mm. Diffuse-spotted reddish pigmentation or unpigmented. Eyes 1 + 1, distinct. Dorsum of head with 4 axial setae and, posteriorly, 4 + 1 axial + 4 slightly spiny setae. Antenna 2.5 × head length; Ant IV with 11 subsegments, bearing 17 – 18 whorls of setae. Trochanters I, II, III with 4, 5, 5 setae, respectively. Femora I, II, III with 14, 15, 14 setae, respectively. Claws I – III slender, without tunica; each with an inner tooth. Empodia I – II with corner tooth and long apical filament extending beyond claw tip; empodium III without tooth, apical filament reaching claw tip. Manubrium with 7 + 7 setae. Dens with 16 setae on posterior side, including 2 massive blunt external spines and 3 moderate internal spines with sharply pointed apices. Mucro with rounded, non-broadened tip; posterior inner lamella with ~ 40 small teeth; outer lamella mostly smooth. Trichobothria ABC forming ~ 160 ° angle, AB <BC. Abd VI in female with 5 broadened circumanal setae per side, finely denticulate basally, sometimes weakly lamellate; dorsal valve with 11 + 2 axial + 11 setae; each lateral valve with 19 setae. Appendices anales curved, deeply bifurcate, palmate, with secondary branching. Member of the Pygmarrhopalites principalis species group (sensu Bretfeld 1999).	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA727FF9EFF1F4A163540FC32.taxon	materials_examined	Type material. Holotype: slide C- 1076 a- 1 (Fig. 5 A), female, W Caucasus, Abkhazia, Gagra Mt. R., Arabika Massif, 2,266 m a. s. l., Sirota Cave, - 22 m, 6. ix. 2017, R. S. Vargovitsh leg. Paratypes (3 males and 10 females on slides): 2 males (C- 1076 - 5; one male dissected and mounted on 4 slides: C- 1076 a- 4 - 1: head; C- 1076 a- 4 - 2: furca; C- 1076 a- 4 - 3: Abd VI; C- 1076 a- 4 - 4: body and legs), 2 females (C- 1076 a- 2; one female dissected and mounted in 4 slides: C- 1076 a- 3 - 1: head; C- 1076 a- 3 - 2: furca; C- 1076 a- 3 - 3: Abd VI; C- 1076 a- 3 - 4: body and legs), collected together with holotype, same cave and collector. Male (C- 1027 a- 1), adult female (C- 1027 a- 3), juv. female (C- 1027 a- 2), W Caucasus, Abkhazia, Gagra Mt. R., Arabika Massif, 2,289 m a. s. l., Tochka Zh Cave, - 10 m, 12. vii. 2016, R. S. Vargovitsh leg. 3 females (C- 1081 a- 9, C- 1081 a- 10, C- 1081 a- 11), W Caucasus, Abkhazia, Gagra Mt. R., Arabika Massif, 2,354 m a. s. l., Nadezhda Cave, - 20 to - 25 m, on liquid surface of Barber traps, exposed 13. vii. 2016 – 08. ix. 2017, R. S. Vargovitsh leg. 3 females on slides (C- 1050 a- 1: 1 ex., C- 1050 a- 2: 2 ex.) W Caucasus, Abkhazia, Gagra Mt. R., Arabika Massif, 2,266 m a. s. l., Moskva Cave, - 10 m, on liquid surface of Barber traps, exposed 06. ix. 2017 – 07. ix. 2018, A. G. Koval and R. S. Vargovitsh leg.; numerous specimens preserved in alcohol. The holotype, 13 slide-mounted paratypes, and numerous alcohol-preserved specimens are deposited in the collection of the Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine, Kyiv.	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA727FF9EFF1F4A163540FC32.taxon	description	Description. Female: Body measurements and ratios as in Tables 1 and 2. Maximum body length without appendages 1.5 – 1.6 mm. Pigmentation in alcohol-preserved specimens absent (Fig. 5 A) or faintly reddish. In adults, reddish pigmentation as diffuse spots, more intense dorsally on head and thorax. Head. (Figs 2 A, 5 D – E). Eyes 1 + 1, relatively large (~ 16 μm), unpigmented or reddish, corresponding to general head pigmentation (Fig. 5 E). Clypeal area with six rows of setae: row a: 4 + 1 axial + 4 setae; rows b, c, e: 5 + 5; rows d, f: 6 + 6; median region M with asymmetrical 3 setae. Interantennal area: row α: 2 + 2; row β: 1 + 1 axial + 1. Frontal area: rows A, C: 2 + 1 axial + 2; row B: 1 + 1 axial + 1; row D: 2 + 2. Setae of rows A, B slender; 4 + 1 axial + 4 setae of rows C and D thickened, slightly spine-like (Figs 2 A, 3 D, 5 D). Row D setae longest in frontal area, ~ 3 × shorter than longest abdominal seta dI- 1 (Table 2). Head dorsum with 4 axial setae (Figs 2 A, 5 D). Chaetotaxy of mouth region. Labrum (Figs 2 A, C; 5 I): labral / prelabral chaetotaxy 4, 5, 5 / 6. Labium: basomedian field (submentum) with 4 setae; basolateral field (mentum) with 5 setae. Labial palp (Fig. 2 B): 5 proximal setae; 5 papillae (A, B, C, D, E), each with long deeply embedded terminal sensillum; 13 guard setae (a 1, b 1 – b 4, d 1 – d 4, e 1 – e 4), a 1 blunt, Ƨ-shaped; lateral process (l. p.) in papilla E short, pointed; 3 hypostomal setae (H, h 1, h 2); papilla B with accessory papilla. Maxillary head as in Fig. 5 J. Maxillary outer lobe (Figs 2 C, 5 I) with 2 setae, including long apical seta with short, thin subparallel basal branch; sublobal plate with 3 sublobal hairs. Oral fold with 2 setae. Antenna (Figs 2 D, 5 F – H): ~ 2.4 × head length, 0.85 × total body length. Mean length ratio of antennal segments I / II / III / IV = 1 / 2.6 / 4.4 / 11.6. Total number of setae: 218 – 220. Ant I with 7 setae, p as microseta (10 μm). Ant II: 15 setae, including two longer interior setae (mean 76 μm). Ant III: 15 simple setae, 5 special setae in apical region (Figs 2 D, 5 H): Api and Ape thin, shorter than simple setae; 2 sense rods (Ant III organ) (mean 9 μm) in shallow pit; Aai as small (7 μm) blunt sensillum. Ant IV subdivided into 11 subsegments, distinctly separated from each other by simple suture (Fig. 2 D). Subsegmental formula: 1 + 9 + 1. Ant IV with 176 setae in 17 whorls: 4 on apical subsegment (AI – AIII + M 1: 33 setae), 9 on median subsegments (M 2 – M 10: 108 setae), 4 on basal subsegment (BA + BM 1 – BM 2 + BB: 36 setae). Each median subsegment with 12 setae (8 ordinary + 4 H - setae or 7 ordinary + 5 H - setae). Whorls M 10 and BA (apical whorl of basal subsegment) likely incomplete, with 11 setae (7 ordinary + 4 H - setae). Besides ordinary setae, apical subsegment with 4 H - setae, hooked AIIpe seta (Fig. 2 D), knobbed and deeply embedded subapical organite (Figs 2 D, 5 F), mossy microseta AIp (Figs 2 D, 5 G), and 11 ordinary microsetae at tip (Fig. 2 D). Legs. Foreleg (Figs 3 A, 5 K): precoxae 1, 2 and coxa with 1, 0, 1 setae, respectively (Fig. 4 A). Trochanter with 4 setae; i 2 strongly curved. Femur with 14 setae; a 4 spine-like, positioned perpendicularly to segment axis (Fig. 3 F); p 1 and p 3 much thinner and shorter than other setae. Tibiotarsus with 45 setae; tibiotarsal formula: 9, 8, 8, 8, 8, 4 (from apex to base); seta Ja (distal whorl I) curved, not spine-like; region F with primary setae e, ae, pe and secondary seta FSa. Pretarsus with single anterior microseta larger than single posterior one. Foot complex (Figs 3 A, 5 K). Claw: slender (max. length 89 μm), without tunica, with small inner tooth and two pairs of lateral teeth; ~ 5 × shorter than tibiotarsus. Empodium: thin, with corner tooth; subequal with claw (max. 86 μm); empodial filament extending beyond claw tip. Midleg (Figs 3 B, 5 L): precoxae 1 and 2 with 1, 1 setae, respectively; precoxal process present; coxa with 3 setae and spine-like microsensillum (Figs 4 A, 6 K). Trochanter: 5 setae; a 1 modified as trochanteral organ (Fig. 6 J). Femur: 15 setae; p 1 thin and short, p 3 thin but subequal with others. Tibiotarsus: 44 setae; tibiotarsal formula: 9, 8, 8, 8, 7, 4 (from apex to base); Ja (distal whorl I) unmodified. Pretarsus with single anterior microseta larger than single posterior one. Foot complex (Figs 3 B, 5 L). Claw: slightly broader and subequal in length to claw I (max. 87 μm), without tunica, with distinct inner tooth and two pairs of lateral teeth; ~ 5.2 × (mean) shorter than tibiotarsus. Empodium: slightly broader than in foreleg; with distinct corner tooth; slightly shorter than in foreleg (~ 1.1 – 1.2 × shorter than claw, max. 75 μm); tip of empodium typically extending beyond claw tip. Hindleg (Figs 3 C, 5 M): precoxae 1 and 2 with 1, 1 setae, respectively; precoxa 1 with process; coxa with 3 setae and spine-like microsensillum (Fig. 4 A). Trochanter similar to midleg: 5 setae, a 1 as trochanteral organ. Femur: 14 setae; p 1 and p 3 as very thin and short microsetae. Tibiotarsus: 44 setae; tibiotarsal formula (apex to base): 9, 8, 8, 8, 7, 4; Ja of whorl I somewhat thickened. Pretarsus with 1 anterior microseta larger than posterior one. Foot complex (Figs 3 C, 5 M). Claw: slightly broader and subequal in length to claw II (max. 85 μm), without tunica, with distinct inner tooth and two pairs of lateral teeth; ~ 6.3 × (mean) shorter than tibiotarsus. Empodium: broad, untoothed, smoothly shaped at its widest part; 1.4 – 1.5 × shorter than claw (max. 62 μm); apical filament very short, tip approximately reaching claw tip. Lengths ratio of tibiotarsi I / II / III = 1 / 1 / 1.2 (Table 2); tibiotarsus of foreleg 1.2 – 1.3 × shorter than head. Ventral tube (Fig. 4 A) with 1 + 1 subapical microsetae on lateral flaps. Tenaculum (Fig. 4 C): each ramus with 3 teeth and basal process; anterior lobe with 2 small apical setae. Furca (Figs 4 B, 6 C – I). Manubrium with 7 + 7 posterior setae. Dens with 23 setae in total: 16 posterior; 7 anterior, formula (apex to base): 3, 2, 1, … 1. Posterior side with Ie (Figs 3 H, 6 G) and IIpe (Figs 3 I, 6 H) as subequal, massive spines with blunt apices; Ii, IIIpi, and IVpi (Figs 3 J, 6 I) as moderate spines with sharply pointed, setaceous apices. Mucro (Figs 4 B; 6 E – F): inner posterior lamella with ~ 40 teeth, outer — with mostly untoothed margin; anterior lamella smooth and moderately developed; tip rounded, not broadened. Dens 1.7 – 1.8 × mucro length, ~ 1.1 × (rarely 1.2 ×) manubrium length. Great abdomen (Figs 4 A, 6 A). Th II with single small sensillum (7 – 8 μm) in row a; 3 setae in row m, with m 1 slightly spine-like (Fig. 3 E), longer than other Th II setae and ~ 3 × shorter than longest setae of posterior dorsal complex (Fig. 3 G). Th III with sensillum in row a (12 – 13 μm) and 3 setae in row m. Anterior part of abdomen: row a with 5 short setae; row m with 4 short setae anterior to trichobothrial complex. Trichobothrial complex (Figs 4 A, 6 A): trichobothria ABC forming very obtuse angle (~ 160 °); AB ~ 1.2 × shorter than BC; seta p located below level of trichobothrium B; seta b 1 almost on line BC, slightly closer to C; c 1 as ordinary seta (~ 30 μm, not microseta), positioned in front of C and seta c 2 — below C. Posterior lateral complex with 6 setae in two rows (3 + 3). Furca base complex with 9 setae in two rows (5 + 4); neosminthuroid seta absent. Central dorsal complex with seta 2 slightly longer than 1 and 3 (Fig. 4 A). Posterior dorsal complex with ~ 25 long setae in 3 longitudinal rows (dI: 9, dII: 9, dIII: 7); longest setae (most posterior in rows dI – dIII) = 95 – 113 μm (Fig. 3 G), ~ 1.4 × longer than hind claw (Table 2). Ventral complex with 3 (rarely 2) setae (Fig. 4 A). Small abdomen. Abd V (Fig. 4 A) with 2 setae and trichobothrium D in row a (a 2 very thin and short), and 2 longer setae in row p. Genital field with 5 (4) + 5 (4) microsetae along anterior margin of genital opening. Abd VI (Figs 4 D, 6 B): dorsal valve with 11 + 2 axial + 11 setae, ms 5 present; each lateral valve with 19 setae. Five setae of circumanal row (mps 1 – mps 3 and mpi 1 – mpi 2) broadened and finely denticulated in basal half, some of them weakly lamellate; relatively long (longest = 80 – 97 μm, ~ 1.2 × shorter than longest posterior seta of great abdomen) (Figs 3 K, 6 B). Appendices anales (Figs 3 L, 5 B): long, deeply bifurcate and palmate in distal half with secondary branches; length ~ 50 μm, width ~ 3.6 μm (basal part) and ~ 20 μm (palmated area in dorso-ventral view); sitting on subglobular somewhat elongated and bilobed basal papilla. In total, normally 62 setae on Abd VI present. Male. Body length ~ 1.2 mm, slightly smaller than female. Chaetotaxy identical to female, except for sexually dimorphic small abdomen (Fig. 4 E). Abd V with ~ 12 + 12 short setae associated with genital opening. Abd VI: dorsal anal valve of with 7 + 2 axial + 7 setae; each lateral valve with 14 setae. Setae of Abd VI unmodified, shorter than in female. Ant IV: subsegment separations strongly pronounced, distinctly more visible than in female; basal subsegment with numerous annulations (Fig. 5 C). Differences in body part sizes and proportions shown in Tables 1 and 2. Variability. Chaetotaxy of posterior surface of dens generally consistent, with 16 setae per dens. However, some variations observed: in one male 16 + 15 setae (Vpe missing); in one female and one juvenile female 16 + 17 setae, both with 4 interior spines instead of usual 3. In the same aberrant female, separations between subsegments of Ant IV indistinct or absent, and one seta on trochanter III bifurcate. In single juvenile female, all spines sharply acuminated rather than blunt.	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA727FF9EFF1F4A163540FC32.taxon	biology_ecology	Ecology and distribution. Pygmarrhopalites arbaicus sp. nov. has so far been recorded in only four of the 17 caves sampled on the Arabika Massif. Its distribution appears to be restricted to the ‘ Central Plateau’ of the Arabika Massif, situated in the Gagra Mountain Range of the Western Caucasus. The species has not been found in other areas of the massif, including the deepest caves such as Krubera and Veryovkina. Most specimens were collected using Barber traps in Nadezhda Cave (at depths of 20 – 25 m; t = 2.1 ° C) and Moskva Cave (at - 10 m; cave temperature ranges from 2.0 to 5.8 ° C). Unlike other troglobiont Collembola species, P. arbaicus sp. nov. was not observed on water surfaces, wet walls, or in other traps in deeper cave sections (down to - 200 m in Nadezhda Cave). A few specimens in Sirota Cave were captured near seeping water among pebbles on the cave floor. Based on its morphology and predominantly terrestrial habitat, the species is classified as an atmobiont troglomorph (Vargovitsh 2022).	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA727FF9EFF1F4A163540FC32.taxon	etymology	Etymology. The species name arbaicus is derived from Arbaika, the historical name for the Arabika Massif. This name itself is a distorted form of the original Abkhaz toponym Arbaika, which translates to “ ridge (of the mountain) Arbaa ”, where aika means “ ridge ” (Kvarchia 2019).	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA727FF9EFF1F4A163540FC32.taxon	discussion	Taxonomic remarks. Pygmarrhopalites arbaicus sp. nov. is clearly placed within the principalis species group sensu Bretfeld (1999), characterized by distinctly palmate appendices anales. Within this group, eight species are known to possess elongated antennae (~ 2 times or more the head length), and five of these also exhibit thickened (spine-like) setae on the head dorsum. A key distinguishing feature of P. arbaicus sp. nov. is the exceptionally high number of subsegments (11) on Ant IV, which sets it apart not only from the aforementioned five species (as outlined in Table 3), but also from all other known members of the genus Pygmarrhopalites. The new species shares the closest resemblance to the Caucasian P. dbari and P. kovali, but can be differentiated by its larger body size, Ant IV divided into more subsegments, and a foot complex in which empodia I and II surpass the tips of their respective claws (see Table 3).	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA72EFF86FF1F4A3835AEFB36.taxon	description	urn: lsid: zoobank. org: act: F 454 BDA 0 - 432 C- 40 DD- 8 D 40 - D 5 FAE 6 A 510 AF Figs 7 – 11, Tables 1 – 2, 4	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA72EFF86FF1F4A3835AEFB36.taxon	diagnosis	Diagnosis. Body length up to 1.4 mm. Diffuse reddish pigmentation. Eyes 1 + 1, indistinct, covered by granulated cuticle and with diffuse reddish pigmentation. Dorsal head setae not spine-like, 3 axial setae present. Antenna 2.8 × head length; Ant IV with 6 subsegments and 13 whorls of setae; several intercalary pseudosubsegments without setae inserted between normal subsegments. Trochanters I, II, III with 4, 5, 5 setae, respectively. Femora I, II, III with 11, 13, 12 setae, respectively. Claws slender, without tunica; claw I without inner tooth (or with extremely reduced one), claws II – III with distinct inner tooth. Empodia short, without apical filaments, tips not reaching claw tip; empodia I and II with small corner tooth, empodium III without tooth. Manubrium with 6 + 6 setae. Dens with 15 (rarely 14) posterior setae, including Ie as blunt spine, IIpe as moderate spine with pointed apex, Ii weakly spine-like and setaceous. Mucro with spoon-like broadened tip; ~ 40 – 45 small teeth on posterior inner lamella, ~ 30 on outer lamella. Trichobothria ABC forming ~ 150 ° angle, AB <BC. Abd VI in female with regular, not broadened circumanal setae, sometimes weakly denticulate basally; dorsal valve with 10 + 2 axial + 10 setae (ms 5 absent); each lateral valve with 18 setae (mi 1 absent). Appendices anales palmated in distal quarter. Member of the Pygmarrhopalites principalis species group (sensu Bretfeld 1999).	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA72EFF86FF1F4A3835AEFB36.taxon	materials_examined	Type material. Holotype: slide C- 1076 a- 6 (Fig. 10 A), female, W Caucasus, Abkhazia, Gagra Mt. R., Arabika Massif, 2,266 m a. s. l., Sirota Cave, - 22 m, 6. ix. 2017, R. S. Vargovitsh leg. Paratypes (2 males, 6 females on slides): 2 males (C- 1081 a- 7, C- 1081 a- 8), 6 females (C- 1081 a- 2, C- 1081 a- 3, C- 1081 a- 4, C- 1081 a- 5, C- 1081 a- 6; one dissected and mounted in 3 slides: C- 1081 a- 1 - 1: head and leg I; C- 1081 a- 1 - 2: legs and great abdomen; C- 1081 a- 1 - 3: Abd VI and furca), W Caucasus, Abkhazia, Gagra Mt. R., Arabika Massif, 2,354 m a. s. l., Nadezhda Cave, - 20 to - 25 m, on liquid surface of Barber traps, exposed 13. vii. 2016 – 08. ix. 2017, R. S. Vargovitsh leg. The holotype and 8 paratypes are deposited in the collection of the Schmalhausen Institute of Zoology, National Academy of Sciences of Ukraine, Kyiv.	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA72EFF86FF1F4A3835AEFB36.taxon	description	Description. Female: Body measurements and ratios in Tables 1 and 2. Maximum body length without appendages 1.4 mm. Pigmentation in alcohol slightly reddish (Fig. 10 A). Head (Figs 7 A, 10 B). Eyes 1 + 1, relatively large (~ 16 μm) but indistinct, poorly defined cornea covered by almost typical cuticular granulation (Fig. 10 B). Clypeal area with six rows of setae, and median region M with 2 setae; row a: 4 + 1 axial + 4 setae; rows b, c, e: 5 + 5; rows d, f: 6 + 6. Interantennal area: row α: 2 + 2; row β: 1 + 1 axial + 1. Frontal area: rows A, D: 2 + 2; row B: 1 + 1 axial + 1; row C: 2 + 1 axial + 2; all setae of frontal area slender; longest (median pair of D - row) slightly thicker (Fig. 8 D), ~ 2 × shorter than longest abdominal seta dI- 1 (Table 2). Head dorsum with 3 axial setae: A 0 (as in Fig. 7 A) or C 0 (as in Fig. 10 B) absent. Chaetotaxy of ventral side as in Fig. 7 A (dashed-line setae). Chaetotaxy of mouth region. Labrum (Fig. 7 A, C): labral / prelabral chaetotaxy 4, 5, 5 / 6. Labium: basomedian field with 4 setae, basolateral field with 5 setae. Labial palp (Fig. 7 B): 5 proximal setae, 5 papillae (A, B, C, D, E) each with long deeply embedded terminal sensillum; 13 guard setae (a 1, b 1 – b 4, d 1 – d 4, e 1 – e 4), a 1 blunt and Ƨshaped; lateral process (l. p.) in papilla E short, pointed; 3 hypostomal setae (H, h 1, h 2); papilla B with accessory papilla. Maxillary head as in Fig. 10 G. Maxillary outer lobe (Fig. 7 C) with 2 setae, including long apical seta with short and thin basal branch, sublobal plate with 3 sublobal hairs. Oral fold with 2 setae. Antenna (Figs 7 D, 10 C – F) ~ 2.8 × head length, 0.92 × total body length. Mean segment length ratio I / II / III / IV = 1 / 3.0 / 5.2 / 12.4. Total number of setae: 166. Ant I with 7 setae, p as microseta (8 μm). Ant II: 15 setae, two anterior setae longer (mean 75 μm). Ant III: 15 simple setae, 5 special setae in apical region (Fig. 10 E – F): Api and Ape thinner and shorter than simple setae; 2 sense rods (Ant III organ) (mean 10.2 μm) in shallow pit; Aai as small (7 μm) blunt sensillum. Ant IV subdivided into 6 subsegments. Basal subsegment separated from median by intercalary pseudosubsegment lacking setae as well as 3 median subsegments from each other (Figs 7 D, 10 C). Three apical subsegments separated from each other by simple suture (Figs 7 D, 10 C). Subsegmental formula: 1 + 4 + 1. Ant IV with 124 setae in 13 whorls: 4 on apical subsegment (AI – AIII + M 1: 33 setae), 4 on median subsegments (M 2 – M 5: 60 setae), 5 on basal subsegment (BA + BM 1 – BM 3 + BB: 31 setae). Each middle subsegment with 12 setae (7 ordinary + 5 thin H - setae or 8 ordinary + 4 H - setae). Chaetotaxy of whorl BA resembles that of M - whorls, with 8 ordinary setae and 4 H - setae. Apical subsegment, besides regular setae, with 4 H - setae, hooked AIIpe seta, knobbed and deeply embedded subapical organite, mossy microseta AIp, and 11 ordinary microsetae at tip (Fig. 7 D). Legs. Foreleg (Figs 8 A, 10 I): precoxae 1, 2 and coxa with 1, 0, 1 setae, respectively (Fig. 9 A). Trochanter with 4 setae; i 2 strongly curved. Femur with 11 setae; a 4 slightly thickened (Fig. 8 F), oriented perpendicularly to segment axis; p 1 and p 3 much thinner than other setae; p 1 as microseta about twice shorter than p 3. Tibiotarsus with 44 setae; tibiotarsal formula: 9, 8, 8, 8, 7, 4 (from apex to base); Ja of distal whorl I curved, not spine-like; region F with secondary FSa seta present. Pretarsus with single anterior microseta lager than posterior one. Foot complex (Figs 8 A, 10 I). Claw: slender (max. 80 μm), without tunica, without or with vestigial inner tooth, with two pairs of barely visible lateral teeth; ~ 5.3 × (mean) shorter than tibiotarsus. Empodium: thin, with small corner tooth; ~ 1.7 × shorter than claw (max. 52 μm); tip of empodium far not reaching claw tip. Midleg (Figs 8 B, 10 J): precoxae 1 and 2 with 1, 1 setae, respectively; precoxal process present; coxa with 3 setae and spine-like microsensillum. Trochanter with 5 setae, a 1 as trochanteral organ (Fig. 10 H). Femur with 13 setae; p 1 and p 3 as thin, short microsetae. Tibiotarsus with 44 setae; tibiotarsal formula: 9, 8, 8, 8, 7, 4 (from apex to base); Ja of distal whorl I not modified. Pretarsus with single anterior microseta somewhat larger than posterior one. Foot complex (Figs 8 B, 10 J). Claw: slightly broader and subequal in length to foreclaw (max. 80 μm), without tunica, with distinct inner tooth and two pairs of lateral teeth; ~ 5.4 × (mean) shorter than tibiotarsus. Empodium: broader and shorter than in foreleg, with corner tooth; ~ 1.7 × shorter than claw (max. 48 μm); empodial filament not developed, empodial tip far from reaching claw tip. Hindleg (Figs 8 C, 10 K): precoxae 1 and 2 each with 1 seta; process on precoxa 1 present, coxa with 3 setae and spine-like microsensillum. Trochanter with 5 setae; a 1 as trochanteral organ. Femur with 12 setae; p 1 and p 3 very thin, short microsetae. Tibiotarsus with 45 setae; tibiotarsal formula: 9, 8, 8, 8, 8, 4 (from apex to base); Ja of whorl I slightly thickened. Pretarsus with 1 anterior microseta somewhat larger than posterior one. Foot complex (Figs 8 C, 10 K). Claw: shorter and broader than in fore- and midlegs (max. 69 μm), without tunica, with distinct inner tooth and two pairs of lateral teeth; ~ 7.4 × (mean) shorter than tibiotarsus. Empodium: broad, untoothed, shaped as in Fig. 10 K; 1.5 – 1.6 × shorter than claw (max. 44 μm); lacking apical filament, with tip far from reaching claw tip. Length ratio of tibiotarsi I / II / III = 1 / 1 / 1.17. Length of tibiotarsus I subequal to head. Ventral tube (Fig. 9 A) with 1 + 1 subapical microsetae (9 μm) on lateral flaps. Tenaculum (Figs 9 C, 11 I): each ramus with 3 teeth and basal process; anterior lobe with 2 apical setae. Furca (Figs 9 B, 11 C – H). Manubrium with 6 + 6 posterior setae. Dens with 22 (21) setae: 15 (14) posterior (IIIpi variable); 7 anterior, formula (apex to base): 3, 2, 1, … 1. Posterior side: Ie as blunt spine on projection (Figs 8 M, 11 G); IIpe as moderate spine with sharply pointed setaceous apex (Fig. 8 N); Ii basally thickened (Figs 8 O, 11 H); others unmodified (Fig. 9 B); IIIpi variable, absent in 50 % of individual dentes; IVpi absent. Mucro (Figs 9 B, 11 C – F): inner posterior lamella with 40 – 45 teeth, outer with 30 – 35 teeth; anterior lamella smooth, moderately developed; tip spoon-like, distinctly broadened. Dens 1.9 – 2 × mucro length, ~ 1.3 × (rarely 1.2 ×) manubrium length. Great abdomen (Figs 9 A, 11 A). Th II with single small sensillum (7 μm) in row a; 3 setae in row m, with m 1 unmodified (Fig. 8 E), ~ 3 × shorter than most posterior setae of posterior dorsal complex (Fig. 8 G). Th III with sensillum in row a (17.5 μm) and 3 setae in row m. Anterior part of abdomen: row a with 5 short setae followed by row m with 4 short setae anterior to trichobothrial complex. Trichobothrial complex (Figs 9 A, 11 A): ABC forming very obtuse angle (~ 150 °); AB ~ 1.5 × shorter than BC; seta p located below level of B; b 1 on line BC, midway between B and C; c 1 as ordinary seta (~ 28 μm, not microseta), in front of C; c 2 below C. Posterior lateral complex with 5 setae in two rows (2 + 3). Furca base complex with 9 setae in two rows (5 + 4); neosminthuroid seta absent. Central dorsal complex with seta 2 little longer than 1 and 3. Posterior dorsal complex with ~ 20 long setae in 3 longitudinal rows (dI: 8, dII: 7, dIII: 5); longest (posteriormost in rows dI – dIII) = 87 – 105 μm (Fig. 8 G), ~ 1.5 × longer than hind claw (Table 2). Ventral complex with 2 or 3 setae. Small abdomen. Abd V (Fig. 9 A) with 2 setae and trichobothrium D in row a (a 2 distinctly thinner and shorter than a 1), and 2 setae in row p. Genital field with 4 + 4 to 6 + 6 microsetae along anterior margin of genital opening. Abd VI (Figs 9 E – F; 11 B, J): dorsal valve with 10 + 2 axial + 10 setae, ms 5 absent; each lateral valve with 18 setae, mi 1 absent. Circumanal setae not broadened (Fig. 11 B), some of them with few denticles in subbasal part (Fig. 8 J – K), rarely with long outgrowth as in seta mps 3 in Fig. 8 I; longest circumanal seta (48 – 80 μm) ~ 1.3 × shorter than longest posterior seta of great abdomen (Fig. 8 G – H). Appendices anales (Figs 8 L, 11 J): moderately palmate in distal quarter; length ~ 35 μm, width ~ 3.6 μm (basal part) and ~ 11 μm (palmated area in dorso-ventral view); sitting on subglobular somewhat elongated basal papilla. In total, normally 58 setae on Abd VI present. Male. Body length ~ 1 mm, smaller than female. Chaetotaxy the same as in female apart sexually dimorphic small abdomen (Fig. 9 D). Abd V with ~ 10 + 10 short setae associated with genital opening. Abd VI: dorsal anal valve with 7 + 2 axial + 7 setae; each lateral valve with 14 setae. Separations between both normal subsegments and intercalary pseudosubsegments of Ant IV strongly expressed, much more distinct than in female (Fig. 10 D); basal subsegment often secondarily subdivided into up to 5 pseudosubsegments by 3 groups of annulations (5 – 8 annuli in each) (Fig. 10 D). Differences in size of body parts and proportions provided in Tables 1 and 2 respectively. Variability. Head dorsum with 3 axial setae, though their positions may vary slightly. Inner tooth in claw of foreleg extremely small or absent. Number of setae in ventral complex of great abdomen varies from 3 to 0. In one female seta mps 2 of Abd VI absent (marked as variable seta in Fig. 9 E). Some circumanal setae with or without few small teeth or long outgrow (Figs 8 I, 11 B).	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA72EFF86FF1F4A3835AEFB36.taxon	biology_ecology	Ecology and distribution. Pygmarrhopalites trisetosus sp. nov. has only been found in two of the 17 caves sampled within the Arabika Massif, where it co-occurs with P. arbaicus sp. nov. This limited presence suggests a restricted distribution, likely confined to the ‘ Central Plateau’ of the Arabika Massif, located in the Gagra Mountain Range, Western Caucasus. Eight specimens were captured using Barber traps at depths of 20 and 25 m in Nadezhda Cave, where the temperature was 2 ° C. Unlike some other troglobiont Collembola species, no specimen of P. trisetosus sp. nov. was observed on the water surface, wet walls, or in other traps set deeper within the cave, down to - 200 m. The only manually collected specimen was found in Sirota Cave, near seeping water amongst pebbles, together with a few specimens of P. arbaicus sp. nov. Based on its morphology and preferred habitat, P. trisetosus sp. nov. can be classified as belonging to the atmobiont troglomorph life form (Vargovitsh 2022).	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA72EFF86FF1F4A3835AEFB36.taxon	etymology	Etymology. The species name trisetosus refers to the presence of only three (not four or five as usual) axial setae on the head dorsum, within the interantennal and frontal areas, a rare characteristic within the Arrhopalitidae.	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA72EFF86FF1F4A3835AEFB36.taxon	discussion	Taxonomic remarks. The new species belongs to the principalis species group (Bretfeld 1999), characterized by palmate appendices anales. Among the known Caucasian species, P. trisetosus sp. nov. most closely resembles P. dbari from Psyrtskha Cave in Novy Afon, sharing several diagnostic features: elongated antennae (up to 3 × head length) with subsegments separated by intercalary bare pseudosubsegments on Ant IV (males also possessing annulating zones on the basal subsegment); shape of head dorsum setae (only slightly spiny in P. dbari); chaetotaxy of the great abdomen; shape of female circumanal setae; shape of the foot complex; presence of 2 external and 1 internal spine-like setae on the dens. Key differences between P. trisetosus sp. nov. and P. dbari include: larger body size (1.3 mm vs. 1 mm); reduced number of axial setae on the head dorsum (3 vs. 4); number of subsegments on Ant IV (6 vs. 7); number of setae on the dorsal valve of Abd VI (10 + 2 + 10 vs. 11 + 2 + 11; ms 5 absent in P. trisetosus sp. nov.); setae on lateral valves of Abd VI (18 vs. 20); dorsal setae on manubrium (6 + 6 vs. 7 + 7); number of posterior setae on the dens (15 vs. 16) with IVpi absent in P. trisetosus sp. nov. The presence of only three axial setae on the head dorsum is a particularly striking feature of P. trisetosus sp. nov., as most Arrhopalitidae have four or five. A similar reduction has only been documented in P. maestrazgoensis Jordana, Fadrique & Baquero, 2012 (Jordana et al. 2012 b) and in a P. principalis population from Fennoscandia (Fjellberg 2007: 190), though this character remains unknown or unclarified in many incompletely described species. The subdivision of Ant IV into 6 subsegments in P. trisetosus sp. nov. is a trait shared with several other species of the principalis group. However, those species typically possess spine-like setae on the head dorsum (except P. ashcraftensis Zeppelini, Taylor & Slay, 2009) and a 2 + 3 spine arrangement on the dens, whereas the new species has only 2 + 1. Pygmarrhopalites trisetosus sp. nov. differs from North American P. ashcraftensis in several aspects, including longer antennae (Ant / head ratio 2.8 vs. 1.8), fewer axial setae on head dorsum (3 vs. 5), absence of a corner tooth on empodium III (present in P. ashcraftensis), and fewer spines on dens (2 + 1 vs. 2 + 3). Further comparative morphological data for other members of the principalis group with elongate antennae and thin dorsal head setae are provided in Table 4	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA735FF85FF1F4CB1377FFAA6.taxon	materials_examined	Material examined a) 3 females on slides (C- 1085 - 1, C- 1085 - 2, C- 1085 - 3): W Caucasus, Abkhazia, Gagra Mt. R., Arabika Massif, 1,805 m a. s. l., Trechus Grotto, 5 – 10 m from entrance, on liquid surface of Barber traps, 9. vii. 2016 – 12. ix. 2017, A. G. Koval and R. S. Vargovitsh leg.; numerous specimens from same locality, same collectors, same method, preserved in alcohol (9. vii. 2016, 12. ix. 2017, 14. ix. 2018). b) 2 females on slides (C- 1086 a- 1, C- 1086 a- 2): W Caucasus, Abkhazia, Gagra Mt. R., Arabika Massif, 1,980 m a. s. l., Treugolnaya Cave, 10 – 15 m from entrance, on liquid surface of Barber traps, 12. ix. 2017, R. S. Vargovitsh and A. G. Koval leg.; numerous specimens from same locality preserved in alcohol. c) 1 female on slide (C- 1084 a- 1): W Caucasus, Abkhazia, Gagra Mt. R., Arabika Massif, 2,223 m a. s. l., Zh- 13 Cave, - 5 m, on liquid surface of Barber trap, 11. ix. 2017, A. G. Koval and R. S. Vargovitsh leg.	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA735FF85FF1F4CB1377FFAA6.taxon	discussion	Taxonomic remarks. The examined specimens generally correspond to the original descriptions of P. sericus (Gisin 1947, 1960): body length ~ 0.7 mm; body and eyes with greyish pigmentation; head dorsum bearing ordinary setae, with 2 + 2 posterior setae thicker than anterior ones; Ant IV divided into 5 subsegments, basal subsegment ~ 1.3 × as long as apical; all claws with inner tooth; Abd VI with 13 broadened setae; appendices anales palmated (principalis type); dens chaetotaxy as in P. principalis, including 2 outer and 3 inner distinctly spine-like setae. Additional characters observed in the Caucasian material include: body length 0.7 – 0.8 mm; antenna 1.5 – 1.6 × head length; basal subsegment of Ant IV slightly shorter than Ant III; head dorsum with 4 unpaired axial setae and with lateral seta D 2 of the most posterior D - row thicker than others; seta m 1 of Th II thick (much thicker than all other setae on great abdomen) and relatively long; circumanal setae longer than posterior abdominal setae; all claws with tunica; empodium I with corner tooth, empodia II – III without; empodial filaments of legs I – II distinctly overtopping corresponding claw, and of leg III reaching or overtopping claw tip; tenaculum with 2 setae; manubrium with 6 + 6 setae; mucro with narrowed, almost pointed tip. The thickness of head dorsum setae varies among cave populations: thin in specimens from Trechus Grotto, and slightly spine-like — especially seta D 2 — in those from Treugolnaya and Zh- 13 caves. It should be emphasized that Gisin’s (1947, 1960) original descriptions, as well as some subsequent descriptions of the species, are brief and omit several key characteristics. Consequently, comparison with the type material is necessary for accurate identification of the Caucasian populations.	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
8F2F2F2DA735FF85FF1F4CB1377FFAA6.taxon	distribution	Distribution. Pygmarrhopalites sericus is a Western Palaearctic species, widely distributed in Europe; it has also been recorded in Morocco (Thibaud & Massoud 1980) and the Middle Ural region of Russia (Kuznetsova 2009). It has not been previously reported from the Caucasus.	en	Vargovitsh, Robert S. (2025): Antennal troglomorphy in Arrhopalitidae (Collembola: Symphypleona) with the description of two new cave Pygmarrhopalites Vargovitsh, 2009 species from the Arabika Massif in the Caucasus. Zootaxa 5673 (4): 523-556, DOI: 10.11646/zootaxa.5673.4.3, URL: https://doi.org/10.11646/zootaxa.5673.4.3
