Steneotarsonemus (Neosteneotarsonemus) patagoniensis Khaustov & Tolstikov, 2025, sp. nov.

Steneotarsonemus (Neosteneotarsonemus) patagoniensis sp. nov. (Figs. 7–12) http://zoobank.org/ urn:lsid:zoobank.org:act: EE316BED-28AB-4729-83B8-10EB7C86303B Description (female) Length of idiosoma 303 (292–305), width 184 (170–185). Idiosomal dorsum (Figs. 7A, 10A, 11A, C, E) – Idiosoma elongated in outline. All dorsal shields with uniform small round puncta (Figs. 11A, C, E). Posterior parts of prodorsal shield and tergites C, D, and EF with delicate striae. Anterior margin of prodorsal shield straight. Stigmata and associated tracheae not evident. All dorsal setae smooth; setae v1, sc2, and c2 pointed, other dorsal setae blunt-tipped; setae sc1 setiform. Setae sc2 situated in anterior half of prodorsal shield, slightly posteromesad sc1 (Fig. 11A); setae c1 and c2 situated on imaginary line connecting bases of setae c2 (Fig. 10A). Lengths of dorsal setae: v1 20 (18–20), sc1 10 (10), sc2 70 (57–60), c1 12 (11–12), c2 19 (17–19), d 11 (8–11), e 7 (7), f 9 (9), h 10 (9–10). Distances between setae: v1–v1 37 (36–37), v2– v2 38 (35–40), sc1–sc1 76 (74–76), sc2–sc2 65 (65–70), c1–c1 48 (44–48), c2–c2 125 (115–125), c1–c2 38 (36–40), d–d 81 (73–75), e–e 83 (83–84), e–f 21 (21–23), f–f 42 (38–40), h–h 38 (44–47). Idiosomal venter (Figs. 7B, 10B, 11B, D, F) – Ventral plates with very small and hardly visible puncta (Figs. 11B, D, F). All ventral setae smooth; setae 3a pointed, other ventral setae blunt-tipped. Pits 1b and 2b small, round. Setae 1a located on or near anterior margin of apodemes 1; setae 2a located well posteriad middle part of apodemes 2. Apodemes 1 fused with prosternal apodeme; apodemes 2 fused with prosternal apodeme (Fig. 11B) or in some specimens median ends diffuse near prosternal apodeme; sejugal apodeme represented by small reniform sclerites; apodemes 3 without anterior projections; apodemes 4 thin and long; poststernal apodeme strongly reduced and poorly visible (Fig. 11D), in some specimens not visible. Tegula length 11 (10–11), maximum width 28 (26–28). Anterior margin of posterior sternal plate and posterior margins of lateral and aggenital plates with delicate striae. Lengths of ventral setae: 1a 5 (5), 2a 6 (6–7), 3a 25 (22–25), 3b 7 (7–8), ps 8 (7–8). Gnathosoma (Fig. 12) – Gnathosomal capsule trapezoidal in outline. Length of gnathosomal capsule 42 (42–44), width 43 (43–47). Dorsomedian apodeme well developed and divided posteriorly. Gnathosoma with dorsal pair of setae ch 26 (25–26) distinctly longer than subcapitular setae m 10 (10–11); both setae pointed; setae ch weakly barbed, m pointed; postpalpal setae needlelike, situated lateroventrally. Cheliceral levers well developed, nearly 2/3 the length of cheliceral stylets. Palpi very short, with at least one pair of setiform structures distally and three pairs of tiny projections ventrally. Pharynx poorly sclerotized, thin-walled, almost horseshoe-shaped (Fig. 12A). A pair of very thin, long and hardly visible tracheae comes from posterodorsal part of gnathosoma into propodosoma (Fig. 12B). Legs (Figs. 8, 9) – Lengths of legs: I 60 (58–61), II 53 (50–54), III 56 (51–55), IV 54 (45–48). Setae (u) of tarsus I and u” of tarsi II and III not evident. Number of setae and solenidia on femur, genu, tibia, and tarsus, respectively: leg I: 4 (d, l’, l”, v”)-4 (l’, l”, v’, v”)-6(2)(d, l’, l”, v’, v”, k, φ1, φ2) + 8(l) (tc’, tc”, p’, p”, pl”, s, pv’, pv”, ω); leg II: 3 (d, l’, v”)-3 (l’, l”, v’)-4 (d, l’, v’, v”)-6(l) (pl”, tc’, tc”, u’, pv’, pv”, ω); leg III: 1 (v’)+3 (l’, l”, v’)-4 (d, l’, v’, v”)-5 (tc’, tc”, u’, pv’, pv”); Leg IV: 1+1 (v’Fe, v’Ge)-1+1 (v’Ti, tc”). Leg I (Fig. 8A). Tarsal claw small, hooked. Solenidion ω digitiform, φ1 and φ2 slightly capitate; seta k 5 (5) rod-shaped. Lengths of solenidia: ω 7 (7), φ1 6 (6–7), φ2 4 (4). Setae (tc) and (p) of tibiotarsus smooth, blunt-tipped, eupathid-like; tc” situated between p’ and p”; setae (tc) shorter than (p). Seta s of tibiotarsus truncated distally, sometimes slightly bifid (Fig. 8 A’); setae d, l’, l” of femur, v’, v” of genu, and pv” of tibiotarsus blunt-tipped, other leg setae pointed; at least setae l” of femur, v’ and v” of genu weakly barbed, other setae smooth. Seta d of tibiotarsus distinctly longer than other leg setae. Leg II (Fig. 8B). Solenidion ω 5 (5) digitiform. Seta u’ truncated distally (Fig. 8 b’); setae d, l’ of femur, pl” and pv” of tarsus spiniform; seta v’ of genu weakly blunt-tipped, other setae pointed; at least setae l” of genu, d, l’ of tibia and tc” of tarsus weakly barbed, other setae smooth. Empodium striated dorsally. Leg III (Fig. 9A). Empodium and setae u’ and pv” as on tarsus II. All setae smooth; setae v’ of femur, l’, v’ of genu, and l’ of tibia weakly blunt-tipped, other setae pointed. Leg IV (Fig. 9B). All setae smooth; seta tc” pointed, other leg setae blunt-tipped; seta tc” of tibiotarsus long, whip-like. Type material Holotype: female, slide ZISP T-Tar-005, Chile, vicinity of Punta Arenas, swamp, in Sphagnum sp., 53° 38′ 02.8″ S, 65° 31′ 01.6″ W, 18 November 2014, coll. V.A. Stolbov; paratypes: 3 females, Chile, Patagonia, Tierra del Fuego island, 54° 29′ 550′′ S, 068° 43′ 103′′ W, from Sphagnum sp. in the swamp, 3 November 2015, coll. A.A. Khaustov. Type deposition The holotype is deposited in the collection of the Zoological Institute of RAS, Saint Petersburg, Russia; other paratypes are deposited in the mite collection of the Museum of Zoology, University of Tyumen, Tyumen, Russia. Etymology The specific epithet of the new species refers to geographical distribution in Patagonia. Differential diagnosis Based on the key to species of the subgenus Neosteneotarsonemus provided by Lin & Zhang (2005), female of the new species is most similar to S. (N). ramus Lin & Zhang, 2005 in having setae c2 longer than c1 and setae 2a situated well posteriad apodemes 2. The new species differs from S. (N). ramus in having setae c1 and c2 located on imaginary transverse line connecting bases of setae c2 (setae c1 located well posteriad imaginary transverse line connecting bases of setae c 2 in S. (N). ramus); apodemes 2 fused with prosternal apodeme (apodemes 2 not fused with prosternal apodeme in S. (N). ramus); setae v1 pointed (setae v1 blunt-tipped in S. (N). ramus); and in having four setae on femur I (three setae on femur I in S. (N). ramus). Female of the new species also similar to S. (N.) kerguelenensis (Fain, 1976) in having apodemes 2 fused with prosternal apodeme. The new species differs from S. (N.) kerguelenensis in having setae 2a located well posteriad apodemes 2 (setae 2a located near posterior margin of apodemes 2 in S. (N.) kerguelenensis); setae c1 and c2 located on imaginary transverse line connecting bases of setae c2 (setae c1 located well posteriad imaginary transverse line connecting bases of setae c 2 in S. (N.) kerguelenensis); and setae v1 distinctly longer than sc1 (setae v1 and sc1 subequal in length in S. (N.) kerguelenensis). Remark The genus Steneotarsonemus is recorded from Chile for the first time.