taxonID	type	description	language	source
03B6712AE526FF85FF09F8928694F85F.taxon	type_taxon	Type species: Steneotarsonemus panshini Wainstein & Beglarov, 1968, by original designation	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE526FF85FF09F8928694F85F.taxon	diagnosis	Diagnosis. As of Mitrofanov & Sharonov (1988).	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE525FF82FF09FF0B81FDFED7.taxon	diagnosis	Diagnosis. Female. Remnants of sejugal apodeme with long anterolateral part; prosternal apodeme well sclerotized posteriad juncture of prosternal apodeme and apodemes 2; apodemes 2 almost fused with prosternal apodeme; apodeme 3 without anterior projection; poststernal apodeme present, without distinct anterior bifurcation; setae 3 b needle-like.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE525FF82FF09FF0B81FDFED7.taxon	description	Description Female. Idiosomal dorsum (Figs 1 A, 4 A, 5 B). Body elongate, poorly sclerotized. Length of idiosoma 280 – 310, width 120 – 140. All dorsal shields with uniform small and hardly visible round puncta. Posterior parts of prodorsal shield and tergites C, D, and EF with delicate striae. Anterior margin of prodorsal shield with wide tongue-like elongation (Fig. 5 B). Stigmata located posterolaterad setae v 1. Tracheal trunks divided medially and with poorly sclerotized sacs. Setae v 1, sc 2, and c 2 pointed, other dorsal setae blunt-tipped; at least setae h weakly barbed; trichobothria sc 1 claviform, with slightly attenuate apex. Setae sc 2 situated in anterior half of prodorsal shield; pits v 2 located anteriad setae sc 2; setae c 1 situated posteriad imaginary line connecting bases of setae c 2. Lengths of dorsal setae: v 1 19 – 20, sc 2 70 – 77, c 1 11 – 12, c 2 18 – 19, d 7 – 8, e 8 – 9, f 8 – 9, h 9 – 11. Distances between setae: v 1 – v 1 28 – 31, sc 2 – sc 2 52 – 56, c 1 – c 1 48 – 55, c 2 – c 2 108 – 118, c 1 – c 2 33 – 38, d – d 56 – 57, e – e 75 – 80, e – f 26 – 27, f – f 25 – 26, h – h 39 – 42. Idiosomal venter (Figs 1 B, 4 B, 5 A, С, D). Soft cuticle between gnathosoma and anterior sternal plate aparantly smooth. Ventral plates with very small and hardly visible puncta. All ventral setae smooth; setae 3 a pointed, other ventral setae needle-like. Pits 1 b and 2 b small, round. Setae 1 a located on apodemes 1; setae 2 a located just posteriad and slightly overlapping middle part of apodemes 2. Apodemes 1 very short, fused with prosternal apodeme; apodemes 2 almost fused with prosternal apodeme; prosternal apodeme well sclerotized posteriad juncture of prosternal apodeme and apodemes 2 and diffuse posteriorly; remnants of sejugal apodeme with long anterolateral part (Figs 5 A, C); apodemes 3 without anterior projections; apodemes 4 thin and long and not fused with poorly developed poststernal apodeme; posterior part of poststernal apodeme weakly sclerotized, anterior bifurcation of poststernal apodeme not evident. Tegula length 10, maximum width 14 – 15. Anterior margin of posterior sternal plate and posterior margins of lateral and aggenital plates with delicate striae. Lengths of ventral setae: 1 a 4 – 5, 2 a 5 – 6, 3 a 27 – 30, 3 b 7 – 8, ps 11 – 13. Gnathosoma. Gnathosomal capsule subcircular in outline. Length of gnathosomal capsule 37 – 40, width 34 – 36. Dorsomedian apodeme present posteriorly. Gnathosoma with dorsal pair of setae ch 14 – 16 distinctly longer than subcapitular setae m 7 – 8; both setae pointed; setae ch weakly barbed, postpalpal setae not seen. Cheliceral levers well developed, nearly 2 / 3 length of cheliceral stylets. Palpi very short, with two pairs of blunt-tipped subequal in length setiform structures (dFe and dGe) distally and three pairs of tiny projections ventrally. Pharynx well sclerotized, almost horseshoe-shaped (Fig. 5 C). Legs (Figs 2, 3). Setae (u) of tarsus I and u ” of tarsi II and III not included in setal count. 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, φ 1, φ 2) + 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. 2 A). Tarsal claw small, slightly bent distally. Solenidion ω slightly clavate, φ 1 and φ 2 slightly capitate; seta k 5 rod-shaped. Lengths of solenidia: ω 6, φ 1 6, φ 2 4. Setae (tc) and (p) of tibiotarsus smooth, blunt-tipped, eupathid-like; tc ” situated between p’ and p ”; setae (tc) subequal with (p). Seta s of tibiotarsus truncated distally; setae d, l ” of femur, and l’ of genu spiniform; seta l’ of femur blunt-tipped, other leg setae pointed; at least setae l ”, v ” of genu, and d of tibiotarsus weakly barbed, other setae smooth. Seta d of tibiotarsus distinctly longer than other leg setae. Leg II (Fig. 2 B). Solenidion ω 5 – 6 weakly clavate. Seta u’ truncated distally; setae d of femur and pl ” of tarsus spiniform; setae l’ of femur and l’ of genu blunt-tipped, other setae pointed; at least seta l’ of genu weakly barbed. Seta l’ of genu more than twice longer than l’ of femur. Empodium longitudinally striated dorsally. Leg III (Fig. 3 A). Empodium and seta u’ as on tarsus II. All leg setae apparently smooth; seta v’ of femur weakly blunt-tipped, other setae pointed. Leg IV (Fig. 3 B). All setae smooth; setae v’Ge and v’Ti blunt-tipped, other leg setae pointed; seta tc ” of tibiotarsus long, whip-like. Male and larva unknown.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE525FF82FF09FF0B81FDFED7.taxon	materials_examined	Material examined. Syntype, 41 females: slide 3481 / 1, Crimea, Simferopol district, vicinity of Kizil-Koba cave, on cereals, 28 June 1981, collected by A. A. Sharonov.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE525FF82FF09FF0B81FDFED7.taxon	discussion	Remark. The examined syntype is in good condition. Most of the morphological structures are clearly visible.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE521FF8DFF09F9BC8574FE42.taxon	description	Figures 6 – 9	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE521FF8DFF09F9BC8574FE42.taxon	diagnosis	Diagnosis. Female. Prodorsum with a pair of small reniform apodemes in posterior part; remnants of sejugal apodeme with long anterolateral part; prosternal apodeme well sclerotized posteriad juncture of prosternal apodeme and apodemes 2; apodemes 2 not fused with prosternal apodeme; apodeme 3 without anterior projection; poststernal apodeme present, without distinct anterior bifurcation; setae 3 b filiform.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE521FF8DFF09F9BC8574FE42.taxon	description	Description Female. Idiosomal dorsum (Figs 6 A, 8 A, 9 A). Body elongate, poorly sclerotized. Length of idiosoma 215 – 220, width 115 – 120. All dorsal shields with uniform small and hardly visible round puncta. Posterior parts of prodorsal shield and tergites C, D, and EF with delicate striae. Anterior margin of prodorsal shield with narrow tongue-like elongation (Fig. 9 A). Stigmata located posterolaterad setae v 1. Tracheal trunks with divided medially poorly sclerotized sacs. Setae v 1, sc 2, and c 2 pointed, other dorsal setae blunt-tipped; at least setae e and h weakly barbed; trichobothria sc 1 claviform, with slightly attenuate apex. Setae sc 2 situated in anterior half of prodorsal shield; pits v 2 located anteriad setae sc 2; setae c 1 situated posteriad imaginary line connecting bases of setae c 2. Prodorsum with a pair of small reniform apodemes in posterior part. Lengths of dorsal setae: v 1 16 – 17, sc 2 41 – 44, c 1 9, c 2 13 – 14, d 7, e 8 – 9, f 6, h 9 – 10. Distances between setae: v 1 – v 1 24, sc 2 – sc 2 46 – 47, c 1 – c 1 50, c 2 – c 2 99, c 1 – c 2 32 – 33, d – d 46 – 47, e – e 69 – 70, e – f 24 – 25, f – f 21 – 23, h – h 34. Idiosomal venter (Figs 6 B, 8 B, 9 B – F). Soft cuticle between gnathosoma and anterior sternal plate aparantly with delicate transverse striae (Fig. 9 B). Ventral plates with very small and hardly visible puncta. All ventral setae smooth; setae 3 a and 3 b pointed, other ventral setae needle-like. Pits 1 b and 2 b small, round. Setae 1 a located on apodemes 1; setae 2 a located just posteriad middle part of apodemes 2. Apodemes 1 short, fused with prosternal apodeme; apodemes 2 not fused with prosternal apodeme; prosternal apodeme narrowed at level of anteromedial corner of trochanters II, with diffuse gap just after imaginary transverse line connecting proximal ends of apodemes 2, narrower but well sclerotized posteriad this gap (Figs 9 C, E); in two specimens posterior narrow sclerotized part of prosternal apodeme poorly visible (Figs 9 B, D); remnants of sejugal apodeme with long anterolateral part (Figs 9 B – E); apodemes 3 without anterior projections; apodemes 4 thin and long and not fused with poorly developed poststernal apodeme, anterior bifurcation of poststernal apodeme not evident. Tegula length 10, maximum width 17. Anterior margin of posterior sternal plate and posterior margins of lateral and aggenital plates with delicate striae. Lengths of ventral setae: 1 a 4, 2 a 5, 3 a 42 – 46, 3 b 12 – 13, ps 5. Gnathosoma. Gnathosomal capsule subcircular in outline. Length of gnathosomal capsule 28 – 29, width 30. Dorsomedian apodeme not evident. Gnathosoma with dorsal pair of setae ch 14 distinctly longer than subcapitular setae m 8; both setae pointed; setae ch weakly barbed, postpalpal setae located laterally. Cheliceral levers well developed, nearly 2 / 3 the length of cheliceral stylets. Palpi very short, with two pairs of blunt-tipped subequal in length setiform structures (dFe and dGe) distally and three pairs of tiny projections ventrally. Pharynx well sclerotized, almost horseshoe-shaped similar to that of S. azureus. Legs (Figs 6, 7). Setation of legs as in S. azureus. Leg I (Fig. 7 A). Tarsal claw small, slightly bent distally. Solenidion ω slightly clavate, φ 1 and φ 2 slightly capitate; seta k 3 rod-shaped. Lengths of solenidia: ω 5, φ 1 4, φ 2 3. Setae (tc) and (p) of tibiotarsus smooth, blunt-tipped, eupathid-like; tc ” situated between p’ and p ”; setae (tc) subequal with (p). Seta s of tibiotarsus truncated distally; setae d, l ” of femur, and l’ of genu spiniform; seta l’ of femur blunt-tipped, other leg setae pointed; at least setae l ” of genu and d of tibiotarsus weakly barbed, other setae smooth. Seta d of tibiotarsus distinctly longer than other leg setae. Leg II (Fig. 7 B). Solenidion ω 4 weakly clavate. Seta u’ truncated distally; setae d of femur and pl ” of tarsus spiniform; setae l’ of femur and l’ of genu blunt-tipped, other setae pointed; at least setae l’ of femur and l’, l ” of genu weakly barbed. Seta l’ of genu slightly longer than l’ of femur. Leg III (Fig. 7 C). All leg setae apparently smooth; setae v’ of femur and l’ of genu weakly blunt-tipped, other setae pointed. Leg IV (Fig. 7 D). All setae smooth; setae v’Ge and v’Ti blunt-tipped, other leg setae pointed; seta tc ” of tibiotarsus long, whip-like. Male and larva unknown.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE521FF8DFF09F9BC8574FE42.taxon	materials_examined	Material examined. Syntype, 4 females: slide 3335 / 7, Russia, Tverskaya Oblast, Vologoevskiy district, vicinity of Vypolzovo village, on cereals, 19 October 1980, collected by A. A. Sharonov.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE521FF8DFF09F9BC8574FE42.taxon	discussion	Remark. The examined syntype is in relatively good condition. Most morphological structures are clearly visible. However, the apodemes are poorly visible, and the characteristic well sclerotized posterior part of the prosternal apodeme is poorly visible in two specimens. In original description the authors mentioned 5 syntype specimens of S. cerinus. We found only four specimens.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE52EFF89FF09F9558110F8C0.taxon	diagnosis	Diagnosis. Female. Remnants of sejugal apodeme with very short anterolateral part; prosternal apodeme not sclerotized posteriad imaginary line connecting bases of setae 2 a; apodemes 2 reaching only to bases of setae 2 a; apodeme 3 with short anterior projection; poststernal apodeme absent; setae 3 b filiform; setae dGe almost twice longer than dFe on palps; distance between dorsal idiosomal setae e – f distinctly greater than f – f.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE52EFF89FF09F9558110F8C0.taxon	description	Description Female. Idiosomal dorsum (Figs 10 A, 12 A, 13 A, C). Body elongate, poorly sclerotized. Length of idiosoma 210, width 100. Posterior parts of prodorsal shield and tergites C, D, and EF with delicate striae. Anterior margin of prodorsal shield with semicircular elongation (Fig. 13 A). Stigmata located posterolaterad setae v 1. Tracheal trunks with divided medially poorly sclerotized sacs. Setae sc 2, and c 2 pointed, v 1 weakly blunt-tipped, other dorsal setae needle-like; at least setae v 1 and h weakly barbed; trichobothria sc 1 claviform, with slightly attenuate apex. Setae sc 2 situated in anterior half of prodorsal shield; setae c 1 situated posteriad imaginary line connecting bases of setae c 2. Distance between dorsal idiosomal setae e – f distinctly greater than f – f. Lengths of dorsal setae: v 1 14, sc 2 54, c 1 10, c 2 17, d 8, e 8, f 7, h 10. Distances between setae: v 1 – v 1 33, sc 2 – sc 2 46, c 1 – c 1 40, c 2 – c 2 95, c 1 – c 2 31, d – d 38, e – e 70, e – f 27, f – f 18, h – h 34. Idiosomal venter (Figs 10 B, 12 B, 13 B, D). All ventral setae smooth; setae 3 a and 3 b pointed, other ventral setae needle-like. Setae 1 a located on apodemes 1; setae 2 a located just posteriad median ends of apodemes 2. Apodemes 1 short, fused with prosternal apodeme; apodemes 2 terminate well before prosternal apodeme; prosternal apodeme not sclerotized posteriad imaginary line connecting bases of setae 2 a; remnants of sejugal apodeme with very short anterolateral part; apodemes 3 with short anterior projections; apodemes 4 thin and long; poststernal apodeme absent. Tegula length 16, maximum width 16. Anterior margin of posterior sternal plate and posterior margins of lateral and aggenital plates with delicate striae. Lengths of ventral setae: 1 a 4, 2 a 6, 3 a 22, 3 b 11, ps 9. Gnathosoma. Gnathosomal capsule subcircular in outline. Length of gnathosomal capsule 35, width 36. Dorsomedian apodeme present in posterior part. Gnathosoma with dorsal pair of setae ch 15 distinctly longer than subcapitular setae m 10; both setae pointed; setae ch weakly barbed, postpalpal setae not evident. Cheliceral levers well developed, nearly 2 / 3 the length of cheliceral stylets. Palpi very short, with setae dGe almost twice longer than dFe. Pharynx (Fig. 13 B) well sclerotized, almost horseshoe-shaped similar to that of S. azureus. Legs (Fig. 11). Setation of legs as in S. azureus. Leg I (Fig. 11 A). Tarsal claw small, slightly bent distally. Solenidion ω slightly clavate, φ 1 and φ 2 slightly capitate; seta k 4 rod-shaped. Lengths of solenidia: ω 5, φ 1 5, φ 2 3. Setae (tc) and (p) of tibiotarsus smooth, blunt-tipped, eupathid-like; tc ” situated between p’ and p ”; setae (tc) subequal with (p). Seta s of tibiotarsus truncated distally; seta d of femur spiniform; setae l’ of femur and genu weakly blunt-tipped, other leg setae pointed. Seta d of tibiotarsus distinctly longer than other leg setae. Leg II (Fig. 11 B). Solenidion ω 4 weakly clavate. Seta u’ truncated distally; seta pl ” of tarsus spiniform; setae d, l’ of femur and l’ of genu blunt-tipped, other setae pointed. Seta l’ of genu almost as long as l’ of femur. Leg III (Fig. 11 C). Setae v’ of femur and l’ of genu weakly blunt-tipped, other setae pointed. Leg IV (Fig. 11 D). All setae smooth; setae v’Ge and v’Ti blunt-tipped, other leg setae pointed; seta tc ” of tibiotarsus long, whip-like. Male and larva unknown.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE52EFF89FF09F9558110F8C0.taxon	materials_examined	Material examined. Female holotype and 5 female paratypes on slide 2993 / 6, Russia, Nizhegorodskaya Oblast, Sadovaya station, on Poa pratensis, 10 July 1978, collected by A. A. Sharonov.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE52EFF89FF09F9558110F8C0.taxon	discussion	Remark. In the original descriptions the authors mentioned four specimens of S. porrectus (holotype and 3 paratypes) on the slide 2993 / 6. We found six specimens. The holotype is not separated from the paratypes by any mark. All specimens are in bad or very bad condition. Therefore, the redescription is based on the single best preserved specimen (Fig. 12). However, in this specimen some characters, such as pits of setae v 2, 1 b, 2 b, all cupules, punctation of dorsal and ventral shields, as well as serration of idiosomal and leg setae are not visible.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE529FF9AFF09FA0D85D5FDAB.taxon	description	Figures 14 – 29	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE529FF9AFF09FA0D85D5FDAB.taxon	diagnosis	Diagnosis. Female. Soft cuticle between gnathosoma and anterior sternal plate with distinct transverse wrinkles; prodorsum with a pair of small reniform apodemes in posterior part; remnants of sejugal apodeme with long anterolateral part; prosternal apodeme diffuse posteriad juncture of prosternal apodeme and apodemes 2; apodemes 2 diffusely fused with prosternal apodeme; apodeme 3 with anterior weakly sclerotized spoon-shaped projection; poststernal apodeme present, with distinct anterior bifurcation; setae 3 b filiform.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE529FF9AFF09FA0D85D5FDAB.taxon	description	Description Female (Figs 14 – 17, 24 – 27). Idiosomal dorsum (Figs 14 A, 16 A, 17 B, 24). Body elongate, poorly sclerotized. Length of idiosoma 270 (240 – 270), width 120 (110 – 120). All dorsal shields with uniform small round puncta (Fig. 17 B). Posterior parts of prodorsal shield and tergites C, D, and EF with delicate striae; prodorsum with a pair of small reniform apodemes in posterior part. Anterior margin of prodorsal shield with wide tongue-like elongation (Figs 17 B, 24 C). Stigmata located posterolaterad setae v 1. Tracheal trunks with divided medially poorly sclerotized sacs (Fig. 17 B). Setae v 1, sc 2, and c 2 pointed, other dorsal setae blunt-tipped; at least setae v 1, e and h weakly barbed (Fig. 24 B); trichobothria sc 1 claviform, with slightly attenuate apex (Fig. 25 A). Setae sc 2 situated in anterior half of prodorsal shield; pits v 2 located anteriad setae sc 2; setae c 1 situated posteriad imaginary line connecting bases of setae c 2. Lengths of dorsal setae: v 1 20 (19 – 22), sc 2 55 (49 – 55), c 1 11 (11 – 12), c 2 17 (14 – 17), d 8 (8 – 9), e 9 (8 – 9), f 8 (8 – 9), h 12 (11 – 12). Distances between setae: v 1 – v 1 27 (26 – 28), sc 2 – sc 2 45 (45 – 46), c 1 – c 1 45 (45 – 52), c 2 – c 2 100 (100 – 105), c 1 – c 2 35 (34 – 37), d – d 50 (49 – 53), e – e 75 (75 – 76), e – f 29 (26 – 30), f – f 21 (18 – 22), h – h 44 (37 – 44). Idiosomal venter (Figs 14 B, 16 B, 17 A, C – F, 25 B – D). Soft cuticle between gnathosoma and anterior sternal plate with distinct transverse cuticular projections « wrinkles » (Fig. 25 D). Ventral plates with small puncta (Figs 17 C – F). All ventral setae smooth; setae 3 a and 3 b pointed, other ventral setae needle-like. Pits 1 b and 2 b small, round. Setae 1 a located on apodemes 1, in some specimens seta 1 a situated posteriad apodeme 1 (Fig. 17 D); setae 2 a located just posteriad middle part of apodemes 2. Apodemes 1 short, fused with prosternal apodeme; apodemes 2 diffusely fused with prosternal apodeme; prosternal apodeme narrowed at level of anteromedial corner of trochanters II or with gap (Fig. 17 E), with diffuse part just after imaginary transverse line connecting proximal ends of apodemes 2; some specimens with weakly sclerotized narrow and short apodeme posteriad this gap (Fig. 17 A); remnants of sejugal apodeme with long anterolateral part; apodemes 3 with weakly sclerotized long spoon-shaped anterior projections better visible in phase contrast (Fig. 17 A); apodemes 4 thin and long and usually fused with poorly developed poststernal apodeme, anterior part of poststernal apodeme with characteristic trident (Fig. 17 A). Tegula length 14 (13 – 14), maximum width 17 (16 – 18). Anterior margin of posterior sternal plate and posterior margins of lateral and aggenital plates with delicate striae. Lengths of ventral setae: 1 a 5 (5), 2 a 9 (7 – 9), 3 a 32 (32 – 41), 3 b 15 (12 – 16), ps 8 (7 – 8). Gnathosoma (Figs 25 D, 26 A). Gnathosomal capsule subcircular in outline. Length of gnathosomal capsule 30 (30 – 31), width 32 (31 – 33). Dorsomedian apodeme not evident. Gnathosoma with dorsal pair of setae ch 17 (16 – 17) distinctly longer than subcapitular setae m 10 (10 – 11); both setae pointed; setae ch weakly barbed, postpalpal setae with thickened base, located laterally in shallow groove (Figs 25 D, 26 A). Cheliceral levers well developed, nearly 2 / 3 length of cheliceral stylets. Palpi very short, with two pairs of blunt-tipped subequal in length setiform structures (dFe and dGe) distally and three pairs of tiny projections ventrally (Fig. 25 D). Pharynx well sclerotized, almost horseshoe-shaped similar to that of S. azureus. Legs (Figs 15, 26 B – D, 27). Setation of legs as in S. azureus. Leg I (Figs 15 A, 26 B – D). Tarsal claw small, hooked distally (Fig. 26 B). Solenidion ω slightly clavate, φ 1 and φ 2 slightly capitate; seta k 4 (4) rod-shaped (Fig. 26 C). Lengths of solenidia: ω 6 (6), φ 1 5 (5), φ 2 3 (3). Setae (tc) and (p) of tibiotarsus smooth, blunt-tipped, eupathid-like; tc ” situated between p’ and p ”; setae (tc) subequal with (p). Seta s of tibiotarsus truncated distally; seta d of femur weakly lanceolate, l’, l ” of femur, and l’ of genu blunt-tipped, other leg setae pointed; setae d of femur, l’ of genu, pv ” of tibiotarsus and eupathidia (p), (tc) smooth, other setae weakly barbed (Figs 26 B, D). Seta d of tibiotarsus distinctly longer than other leg setae. Leg II (Figs 15 B, 27 A – C). Empodium striated dorsally. Solenidion ω 5 (5) weakly clavate. Seta u’ truncated distally; seta pl ” of tarsus spiniform, with longitudinal ridges in distal half (Fig. 27 B); seta u ” short, weakly blunt-tipped (Fig. 27 C); setae d, v ” of femur, l’ of tibia, tc’ and (pv) of tarsus smooth, other setae barbed. Seta l’ of genu slightly longer than l’ of femur. Leg III (Figs 15 C, 27 D). Empodium and setae u’, u ” (Fig. 27 D) as on tarsus II. At least setae d, l’, (v) of tibia and (tc) of tarsus weakly barbed, other setae smooth; setae v’ of femur and l’ of genu weakly blunt-tipped, other setae pointed. Leg IV (Fig. 15 D). Seta v’ of tibiotarsus weakly barbed, other setae smooth; setae v’Ge and v’Ti blunt-tipped, other leg setae pointed; seta tc ” of tibiotarsus long, whip-like. Male (Figs 18 – 21). Idiosomal dorsum (Figs 18 A, 21 A). Body oval in outline. Length of idiosoma 205, width 140. All dorsal shields with uniform small round puncta. All dorsal setae smooth; setae sc 1 and c 2 pointed, other dorsal setae blunt-tipped. Setae c 1 situated almost on the same transverse level with setae d. Only cupules ia evident and located anteriad setae c 1 Lengths of dorsal setae: v 1 21, v 2 19, sc 1 66, sc 2 25, c 1 12, c 2 42, d 18, f 13, h 5. Distances between setae: v 1 – v 1 19, v 2 – v 2 24, sc 1 – sc 1 37, sc 2 – sc 2 58, c 1 – c 1 84, c 2 – c 2 120, d – d 40, f – f 31, h – h 12. Idiosomal venter (Figs 18 B, 21 B). Soft cuticle between gnathosoma and anterior sternal plate with distinct transverse cuticular projections as in female. Ventral plates with very small and hardly visible puncta; coxisternal fields I and II with short, broken striae laterad setae 1 a and 2 a; coxisternal fields III and IV without striation. All ventral setae smooth; setae 3 a pointed, other ventral setae weakly blunt-tipped. Pits 1 b and 2 b small, round. Apodemes 1 fused with prosternal apodeme; apodemes 2 well developed and not fused with prosternal apodeme; prosternal apodeme with gap; sejugal apodeme not developed medially and represented by lateral sclerites; apodemes 3 and 4 well developed and not fused by their distal ends; poststernal apodeme well developed; apodemes 5 absent (Fig. 21 B). Lengths of ventral setae: 1 a 7 – 8, 2 a 9 – 10, 3 a 32 – 36, 3 b 19 – 20. Gnathosoma. Gnathosomal capsule as in female. Length of gnathosomal capsule 32, width 34. Lengths of setae: ch 19, m 11. Legs (Figs 19, 20). Number of setae and solenidia on trochanter, femur, genu, tibia, and tarsus, respectively: leg I: 0 - 4 (d, l’, l ”, v ”) - 4 (l’, l ”, v’, v ”) - 6 (2) (d, l’, l ”, v’, v ”, k, φ 1, φ 2) - 8 (l) (tc’, tc ”, p’, p ”, pl ”, s, pv’, pv ”, ω); leg II: 0 - 3 (d, l’, v ”) - 3 (l’, l ”, v’) - 4 (d, l’, v’, v ”) - 6 (l) (pl ”, tc’, tc ”, u’, pv’, pv ”, ω); leg III: 0 - 1 (v’) - 3 (l’, l ”, v’) - 4 (d, l’, v’, v ”) - 4 (tc’, tc ”, u’, pv ”); Leg IV: 1 (v’) - 1 (v’Fe) + 2 (v’Ge, l ” Ge) - 1 (1) (v’, φ) - 3 (tc ”, u’, pv ”). Leg I (Fig. 19 A). In general similar to that of female, except separated tibia and tarsus. Seta d of femur narrowly spiniform, seta l’ of genu filiform and barbed, other setae as in female. Lengths of solenidia and seta k: ω 6, φ 1 6, φ 2 4, k 5. Leg II (Fig. 19 B). Similar to that of female, except empodium incised distally and transversely striated dorsally. Solenidion ω 6. Leg III (Figs 20 A). Empodium as on tarsus II. Seta v’ of femur blunt-tipped, other setae pointed; setae v’ of femur, l ” of genu, d of tibia, and pv ” of tarsus smooth, other setae weakly barbed. Leg IV (Figs 20 B). Seta v’ of tibia weakly barbed, other setae smooth; setae v’ of trochanter and l ” of genu pointed, other leg setae blunt-tipped. Femorogenu with large flange with round thickening near setae v’Fe. Solenidion φ 10 baculiform. Tarsus with single claw. Larva (Figs 22, 23, 28, 29). Idiosomal dorsum (Fig. 22 A). Length of idiosoma 215 – 235, width 110 – 130. All dorsal shields without puncta; prodorsal shield and tergites C and D with longitudinal ridges. Setae v 1, sc 1, sc 2, and c 2 smooth, other dorsal setae barbed; setae sc 2 and c 2 pointed, other dorsal setae blunt-tipped; setae v 2 represented by alveolar pits. Tergites D, EF and H with cupules ia, im, and ih, respectively. Tergite C entire; setae c 1 situated near posterior margin of tergite C. Lengths of dorsal setae: v 1 8 – 9, sc 1 11 – 13, sc 2 47 – 52, c 1 9 – 10, c 2 12 – 15, d 9 – 13, e 10 – 13, f 9 – 15, h 1 20 – 26, h 2 10 – 15. Distances between setae: v 1 – v 1 9 – 12, sc 1 – sc 1 44 – 47, sc 2 – sc 2 33 – 40, c 1 – c 1 43 – 59, c 1 – c 2 37 – 39, c 2 – c 2 72 – 96, d – d 23 – 33, e – e 32 – 39, e – f 9 – 11, f – f 17 – 18, h 1 – h 1 6 – 8, h 1 – h 2 16 – 18, h 2 – h 2 33 – 35. Idiosomal venter (Figs 22 B, 28 A, C). Soft cuticle between gnathosoma and anterior sternal plate smooth. Ventral plates smooth. All ventral setae smooth; setae 3 a pointed, other ventral setae needle-like. Pits 1 b and 2 b small, round. Apodemes 1, 2 and 3 well developed, other apodeme absent. Two pairs of pseudanal setae (Fig. 28 C). Lengths of ventral setae: 1 a 5, 2 a 5, 3 a 27 – 30, 3 b 5 – 6, ps 1 6 – 7, ps 2 6 – 7. Gnathosoma as in female, except strong reduction of postpalpal (pp) setae (Fig. 28 B). Length of gnathosomal capsule 25 – 28, width 29 – 32. Lengths of setae: ch 18, m 10. Legs (Figs 23, 28 D, 29). Setae (u) of tarsus and u ” of tarsi II and III not included in setal count. 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 (1) (d, l’, l ”, v’, v ”, k, φ 1) - 6 (l) (tc’, tc ”, pl ”, s, pv’, pv ”, ω); leg II: 3 (d, l’, v ”) - 3 (l’, l ”, v’) - 4 (d, l’, v’, v ”) - 5 (l) (pl ”, tc’, tc ”, u’, pv ”, ω); leg III: 1 (v’) - 3 (l’, l ”, v’) - 4 (d, l’, v’, v ”) - 4 (tc’, tc ”, u’, pv ”). Leg I (Figs 23 A, 28 D, 29 A). Solenidion φ 2 and setae p’ and p ” absent. Tarsus with a pair of simple tarsal claws (Fig. 28 D). All setae smooth; setae d, l’, l ” of femur, l’, v’, v ” of genu, k, of tibia, and (tc) of tarsus blunt-tipped, other leg setae (except spiniform s) pointed. Lengths of solenidia and seta k: ω 4, φ 1 5, k 4. Leg II (Figs 23 B, 29 B). Solenidion ω 3. At least setae d of tibia and tc ” weakly barbed, other setae smooth; seta pl ” and spiniform, u ’ truncated; setae d and l’ of femur blunt-tipped, other leg setae pointed. Leg III (Figs 23 C, 29 C, D). At least seta tc ” weakly barbed, other leg setae smooth; setae l’ of tibia spiniform (Figs 29 C, D), seta u’ as on tarsus II; seta v’ of femur blunt-tipped, other leg setae pointed.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE529FF9AFF09FA0D85D5FDAB.taxon	materials_examined	Type material. Female holotype, slide ZISP T-Tar- 6, Russia, Tyumenskaya Oblast, city of Tyumen, Gagarin park, on Calamagrostis arundinacea (Poaceae), 10 July 2025, collected by A. A. Khaustov; paratypes: 27 females, 1 male, 8 larvae, same data. Type deposition. The holotype and 5 female paratypes are deposited in the acarological collection of the Zoological Institute of Russian Academy of Sciences, Saint Petersburg, Russia; other paratypes are deposited in the mite collection of the Museum of Zoology, University of Tyumen, Tyumen, Russia.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE529FF9AFF09FA0D85D5FDAB.taxon	etymology	Etymology. The name of the new species is derived from Latin rugosus, meaning wrinkled, and refers to the unusual “ wrinkles ” on soft cuticle between the gnathosoma and anterior sternal plate in the female and male.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE529FF9AFF09FA0D85D5FDAB.taxon	diagnosis	Differential diagnosis. The female of the new species is most similar to S. panshini (compared with original description of Wainstein & Beglarov (1968) and illustration of Livshits et al. (1979 )) in having remnants of the sejugal apodeme with a long anterolateral part, and prosternal apodeme poorly developed posteriad setae 2 a. Females of the new species differs from S. panshini in having anterior spoon-shaped projections on apodemes 3 (vs. absent in S. panshini) and presence of a trident in the anterior part of the poststernal apodeme (vs. poststernal apodeme without trident or bifurcation in S. panshini). Males of the new species differs from S. panshini in the location of setae c 1 at the same transverse level as d (vs. setae c 1 located distinctly anteriad setae d in S. panshini), setae v 1 and v 2 subequal in length (vs. setae v 2 longer than v 1 in S. panshini), and coxisternal plates III smooth (vs. coxisternal plates III with broken striae in S. panshini). Females of the new species are also similar to S. cerinus. The new species differs from S. cerinus in having the prosternal apodeme poorly developed posteriad setae 2 a (vs. prosternal apodeme with well sclerotized part posteriad setae 2 a), distinctly wider anterior projection of anterior margin of prodorsal shield (vs. anterior projection of anterior margin of prodorsal shield narrowly tongue-like in S. cerinus), by longer tegula, in having anterior spoon-shaped projections on apodemes 3 (vs. absent in S. cerinus) and presence of a trident in the anterior part of the poststernal apodeme (vs. poststernal apodeme without trident or bifurcation in S. cerinus).	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE539FFA4FF09FD2F8750F8E1.taxon	description	Figures 30 – 33	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE539FFA4FF09FD2F8750F8E1.taxon	diagnosis	Diagnosis. Female. Body well sclerotized, brown in color; remnants of sejugal apodeme with very short anterolateral part; prosternal apodeme with gap and well sclerotized posteriad imaginary line connecting bases of setae 2 a; apodemes 2 not fused with prosternal apodeme; apodeme 3 without anterior projection; poststernal apodeme absent; setae 3 b filiform; setae dGe dFe on palps subequal in length; distance between dorsal idiosomal setae e – f distinctly shorter than f – f; seta v’ of genu II blunt-tipped, similar to l’ of genu II.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE539FFA4FF09FD2F8750F8E1.taxon	description	Description Female. Idiosomal dorsum (Figs 30 A, 32 A, 33 A, B). Body fusiform, well sclerotized, brown in color (Fig. 32). All dorsal sclerites with tiny round puncta (Figs 33 A, B). Length of idiosoma 270 (260 – 270), width 105 (105 – 110). Pits v 2 located anteriad setae sc 2. Posterior parts of prodorsal shield and tergites C, D, and EF with delicate striae. Anterior margin of prodorsal shield with semicircular elongation (Fig. 33 A). Stigmata prominent, located posterolaterad setae v 1. Tracheal trunks with divided medially strongly sclerotized sacs (Fig. 33 F). Setae v 1, sc 2, and c 2 pointed, other dorsal setae needle-like; at least setae e and h weakly barbed; trichobothria sc 1 claviform, with rounded apex. Setae sc 2 situated in anterior half of prodorsal shield; setae c 1 situated posteriad imaginary line connecting bases of setae c 2. Distance between dorsal idiosomal setae e – f distinctly shorter than f – f. Lengths of dorsal setae: v 1 20 (18 – 20), sc 2 50 (48 – 50), c 1 11 (10 – 11), c 2 16 (16 – 19), d 8 (8), e 8 (7 – 8), f 7 (7), h 9 (8 – 9). Distances between setae: v 1 – v 1 31 (30 – 31), sc 2 – sc 2 50 (48 – 50), c 1 – c 1 46 (46 – 49), c 2 – c 2 96 (96 – 98), c 1 – c 2 32 (32 – 33), d – d 49 (48 – 49), e – e 72 (72 – 73), e – f 18 (18 – 21), f – f 38 (33 – 38), h – h 38 (38 – 39). Idiosomal venter (Figs 30 B, 32 B, 33 C, D). Soft cuticle between gnathosoma and anterior sternal plate smooth. All ventral setae smooth; setae 1 a, 3 a and 3 b pointed, other ventral setae needle-like. Setae 1 a located on apodemes 1; setae 2 a located just posteriad apodemes 2. Apodemes 1 short, fused with prosternal apodeme; apodemes 2 not reaching prosternal apodeme; prosternal apodeme with gap, well sclerotized posteriad imaginary line connecting bases of setae 2 a and slightly bifid posteriorly; remnants of sejugal apodeme with very short anterolateral part (Fig. 33 C); apodemes 3 without anterior projections; apodemes 4 thin and long; poststernal apodeme absent; with more strongly sclerotized spots anteriad apodemes 3 and not connected with apodemes 3 (Fig. 33 D). Tegula length 13 (13), maximum width 22 (22 – 23). Anterior margin of posterior sternal plate and posterior margins of lateral and aggenital plates with delicate striae. Lengths of ventral setae: 1 a 6 (6 – 8), 2 a 6 (6), 3 a 36 (34 – 40), 3 b 16 (14 – 16), ps 7 (7). Gnathosoma. Gnathosomal capsule subcircular in outline. Length of gnathosomal capsule 32 (32), width 31 (31 – 32). Dorsomedian apodeme absent. Gnathosoma with dorsal pair of setae ch 17 (16 – 17) distinctly longer than subcapitular setae m 8 (8 – 9); both setae pointed; setae ch weakly barbed, postpalpal setae situated inside groove and not clearly visible in dorso-ventral view. Cheliceral levers well developed, nearly 2 / 3 the length of cheliceral stylets. Palpi very short, with setae dGe and dFe subequal in length. Pharynx (Fig. 33 E) well sclerotized, almost horseshoe-shaped similar to that of S. azureus. Legs (Fig. 31). Setation of legs as in S. azureus. Leg I (Fig. 31 A). Tarsal claw small, slightly bent distally. Solenidion ω slightly clavate, φ 1 and φ 2 slightly capitate; seta k 3 (3) rod-shaped. Lengths of solenidia: ω 3 (3), φ 1 4 (4), φ 2 2 (2). Setae (tc) and (p) of tibiotarsus smooth, blunt-tipped, eupathid-like; tc ” situated between p’ and p ”; setae (tc) subequal with (p). Seta s of tibiotarsus truncated distally; seta d of femur spiniform; setae l’, l ” of femur, l’ of genu weakly blunt-tipped, other leg setae pointed. Setae l’, l ” of femur, l ”, (v) of genu, and l’ of tibia weakly barbed, other setae smooth. Seta d of tibiotarsus distinctly longer than other leg setae. Leg II (Fig. 31 B). Empodium longitudinally striated dorsally. Solenidion ω 3 (3) weakly clavate. Seta u’ truncated distally; seta pl ” of tarsus spiniform; setae d, l’ of femur, l’ and v’ of genu blunt-tipped, other setae pointed. Setae l’ of femur, l’, l ”, v’ of genu, d of tibia and (tc) of tarsus barbed, other setae smooth. Seta l’ of genu slightly longer than l’ of femur and subequal with v’ of genu. Leg III (Fig. 31 C). Empodium and seta u’ as on tarsus II. Setae v’ of femur and l’ of genu weakly blunt-tipped, other setae pointed; setae v’ of genu and (tc) of tarsus barbed, other setae smooth. Leg IV (Fig. 31 D). All setae smooth; setae v’Ge and v’Ti blunt-tipped, other leg setae pointed; seta tc ” of tibiotarsus long, whip-like. Male and larva unknown.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE539FFA4FF09FD2F8750F8E1.taxon	materials_examined	Type material. Female holotype, slide T-Tar- 7, Russia, Primorsky Krai, vicinities of Khanka lake, 44 ° 46 ' N 132 ° 02 ' E, on Spodiopogon sibiricus (Poaceae), 31 July 2025, collected by A. A. Khaustov; paratypes: 3 females, same data. Type deposition. The holotype and 3 female paratypes are deposited in the acarological collection of the Zoological Institute of Russian Academy of Sciences, Saint Petersburg, Russia.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE539FFA4FF09FD2F8750F8E1.taxon	etymology	Etymology. The name of the new species is derived from Latin fuscus meaning brown, and refers to the unusually strongly sclerotized idiosomal sclerites in the new species.	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
03B6712AE539FFA4FF09FD2F8750F8E1.taxon	diagnosis	Differential diagnosis. The new species is most similar to S. porrectus in having strongly reduced sejugal apodeme remnants and the absence of the poststernal apodeme. The new species differs from S. porrectus in having the prosternal apodeme with a gap and strongly sclerotized posteriad setae 2 a (vs. prosternal apodeme without gap and not sclerotized posteriad setae 2 a in S. porrectus), apodemes 3 without an anterior projection (vs. apodemes 3 with distinct anterior projection in S. porrectus), distance between setae f – f distinctly greater than e – f (vs. distance between setae f – f distinctly shorter than e – f in S. porrectus), idiosomal sclerites strongly sclerotized, brown in color (vs. idiosomal sclerites weakly sclerotized in S. porrectus), and setae dFe and dGe of palps subequal in length (vs. seta dGe of palp distinctly longer than dFe in S. porrectus).	en	Khaustov, Alexander A., Mashkov, Kirill A. (2026): Review of the subgenus Steneotarsonemus (Steneotarsonemoides) (Acari: Heterostigmata: Tarsonemidae) of Russia. Zootaxa 5785 (2): 253-289, DOI: 10.11646/zootaxa.5785.2.2, URL: https://doi.org/10.11646/zootaxa.5785.2.2
