Vietocheyla subiasi, Khaustov & Salavatulin & Tsurikov & Thinh & Khaustov, 2024

Khaustov, Alexander A., Salavatulin, Vladimir M., Tsurikov, Sergey M., Thinh, Nguyen Van & Khaustov, Vladimir A., 2024, Free-living predatory cheyletid mites (Acariformes: Cheyletidae) from Cat Tien National Park, Vietnam, Zootaxa 5556 (1), pp. 268-295 : 282-286

Vietocheyla subiasi sp. nov.

( Figures 17–20 )

Description. Female (n=2) ( Figs 17–19 , 20A ). Length of idiosoma 230 (210), width 170 (175).

Dorsum ( Figs 17A , 20A ). Prodorsal and hysterosomal shields with 11 and 12 pairs of setae, respectively; most dorsal setae fan-shaped ( Fig. 20A ), subequal in length (20–22) and only one pair of posterior setae on hysterosomal shield and one pair posteriad hysterosomal shield widened basally and with attenuate tip. Setae c2 located on separate plates. Dorsal shields ornamented with numerous granules usually connected with delicate striae. Hysterosomal shield with two pairs of poorly visible lyrifissures im and ip. Soft cuticle smoothly striated on podosoma and granulated on opisthosoma; cuticle between gnathosoma and prodorsal shield punctate.

Venter ( Fig. 1B ). Idiosomal venter with three pairs of intercoxal (1a, 3a, 4a), three pairs of aggenital (ag1–ag3), two pairs of genital (g1, g2), and three pairs of pseudanal setae (ps1–ps3); coxisternal fields I with two setae (1b, 1c), coxisternal fields II each with one seta (2c), coxisternal fields III each with two setae (3b, 3c) and coxisternal fields IV each with two setae (4b, 4c). Setae 1b and 3b barbed, widened basally and with attenuate tips; other ventral setae filiform, smooth. Ventral soft cuticle mostly with smooth striae and only posteriad anal opening with small granules. Lyrifissures ih located posterolaterad anal opening.

Gnathosoma ( Figs 18 , 20A ). Length of gnathosomal capsule 62 (64). Protegmen with several transverse striae. Tegmen as on Figure 20A . Peritremes with four pairs of segments. Palpal supracoxal setae (ep) situated laterad fourth peritremal segment. Palpfemur with three setae, one lanceolate and strongly barbed dorsal (d) and two smooth, filiform ventral (v’, v”); palpgenu with two setae, one lanceolate dorsal (d) and smooth, filiform lateral (l”); palptibia with three setae, one barbed and pointed dorsal (d), and two smooth, filiform (l’, l”); setae d on femur, genu and tibia situated on short protuberances. Tibial claw edentate. Tarsus with two comb-like setae (acm, sul), two sickle-like eupathidia (ul’ϛ, ul”ϛ) and one baculiform solenidion (ω); inner comb-like seta (acm) with 18 projections; outer comb-like seta (sul) with 8 projections. Adoral setae smooth, pointed; ao1 slightly shorter than ao2. Subcapitulum with one pair of long filiform setae n.

Legs ( Figs 17A , 19 ). Lengths of legs: leg I 235, leg II 145, leg III 150, leg IV 170. Leg I ( Figs 19A, B ). Tarsus without pretarsus, with very long solenidion ω 170, three very long and finely serrated blunt-tipped eupathid-like setae (tc’ϛ, tc”ϛ, p’ϛ), narrowly lanceolate and barbed guard seta ft, filiform, smooth ventral setae (vs, u’, u”) and tiny smooth and blunt-tipped proral seta p”; tarsal solenidion and guard setae located on distinct nipple. Tibia with four lanceolate setae (d, v’, v”, l”) and baculiform dorsodistal solenidion φ 7; genu with one dorsal fan-shaped (d), one lateral lanceolate setae (l’) and short weakly clavate dorsodistal seta k 3 located in shallow depression, femur with one dorsal fan-shaped (d) and one ventral lanceolate setae (v’); trochanter with one lanceolate seta (v’); leg supracoxal seta (el) weakly clavate, similar in shape to seta k on genu, situated dorsomesad trochanter and usually covered by lateral margins of idiosomal soft cuticle. Leg II ( Fig. 19C ). Tarsus with two smooth pointed tectal setae (tc’, tc”), two weakly barbed, curved and slightly thickened setae (a), three filiform pointed and barbed setae (u’, u”, vs), and long ventral baculiform solenidion ω 20; tibia with one broadly lanceolate seta (d), two lanceolate setae (v’, l”), one filiform smooth and pointed seta (v”) and tiny peg-like dorsodistal solenidion φ 3; genu with one dorsal fan-shaped seta (d) and one lanceolate lateral seta (l’); femur with one dorsal fan-shaped seta (d) and one ventral seta with widened base and attenuate tip (v”); trochanter with one seta with widened base and attenuate tip (v’). Leg III ( Fig. 19D ). Tarsus with two smooth pointed tectal setae (tc’, tc”), two weakly barbed, curved and slightly thickened setae (a), and three filiform pointed and barbed setae (u’, u”, vs); tibia with one broadly lanceolate seta (d), two lanceolate setae (v’, l”), one filiform smooth and pointed seta (v”) and dorsodistal alveolar pit (probably vestige of solenidion φ); genu with one dorsal fan-shaped seta (d) and one lanceolate lateral seta (l’); femur with one dorsal fan-shaped seta (d) and one ventral seta (v’); trochanter with one seta with widened base and attenuate tip (v’). Leg IV ( Fig. 19E ). Tarsus with two smooth pointed tectal setae (tc’, tc”), two weakly barbed, curved and slightly thickened setae (a), and three filiform pointed and barbed setae (u’, u”, vs); tibia with one broadly lanceolate seta (d), two lanceolate setae (v’, l”), one filiform smooth and pointed seta (v”) and dorsodistal round alveolar pit (probably vestige of solenidion φ); genu with one dorsal fan-shaped seta (d) and one lanceolate lateral seta (l’); femur with two fan-shaped seta (d, v’); trochanter with one seta with widened base and attenuate tip (v’).

Tritonymph (n=3) ( Figs 20B–D ). Length of idiosoma 175–180, width 145–160.

Dorsum ( Figs 20C, D ). Prodorsal ( Fig. 20C ) and hysterosomal ( Fig. 20B ) shields each with eight pairs of setae. Setae c2 located on separate plate. Dorsal idiosomal setae narrower than in female.

Venter ( Fig. 20D ). Venter of podosoma as in female. Opisthosomal venter with two pairs of aggenital setae, one pair of genital setae, three pairs of pseudanal setae, and one pair of setae with widened base and attenuate tip posteriad anal opening.

Gnathosoma and legs as in female.

Male, protonymph and larva unknown.

Type material. Female holotype, slide VS101222 , Vietnam, Cat Tien National Park, on Dipterocarpus alatus ; crown, bark on a tree trunk at the height of 20–25 m; 11°26′34.64′′ N 107°26′06.67′′ E; 20.XI.2022 – 10.XII.2022, collected by V.M. Salavatulin ; paratypes: 1 female and 3 TN, same data .

Type deposition. All specimens are deposited in the acarological collection of the Museum of Zoology, University of Tyumen, Tyumen, Russia.

Etymology. This species is named after Prof. Dr. Luis. S. Subías, the famous Spanish oribatologist.

Figures

FIGURE 1. Cheletogenes vietnamiensis sp. nov., female: A—dorsum of idiosoma; B—venter of idiosoma.

FIGURE 17. Vietocheyla subiasi gen. and sp. nov., female: A—general view dorsally; B—general view ventrally (legs omitted).

FIGURE 18. Vietocheyla subiasi gen. and sp. nov., female: A—gnathosoma, dorsal aspect; B—gnathosoma, ventral aspect.

FIGURE 19. Vietocheyla subiasi gen. and sp. nov., female: A—distal part of tibia and tarsus, dorsal aspect; B—distal part of tarsus I, ventral aspect; C–E—distal part of tibiae and tarsi II–IV, respectively, dorsal aspect.

FIGURE 20. DIC micrographs of Vietocheyla subiasi gen. and sp. nov., female (A) and tritonymph (B–D): A—distal part of prodorsum and gnathosoma, dorsal aspec; B—hysterosoma, dorsal aspect; C—prodorsum; D—hysterosoma, ventral aspect.