Athyreacarus brevisetosus sp. nov.

(Figs 8–12)

Description. Female. Body almost oval. Length of idiosoma 445 (425–500), width 280 (260–335).

Gnathosoma (Fig. 12F). Gnathosomal capsule, excluding palps, almost oval, length 65 (62–66), width 73 (72– 78). Two pairs of barbed, blunt-ended cheliceral setae cha 29 (28–31) and chb 20 (19–23). Postpalpal setae (pp) 12 (12–13) needle-like. Setae m 15 (15–17) and n 50 (49–58) pointed; setae m smooth, n weakly barbed. Setae dFe 14 (13–17) and dGe 33 (31–37) barbed; setae dFe blunt-ended, dGe pointed. Tibial claw slightly hooked with short basal projection; cheliceral stylets with distinct subapical tooth (Fig. 12F). Pharynx typical for the genus.

Idiosomal dorsum (Figs 8A, 11A, 12A, C, E). All dorsal shields with numerous very small densely distributed dimples; lateral part of tergite D and anterior halves of tergites EF and H with scale-like microsculpture (Fig. 12E). Hysterosomal shields almost completely covering hysterosoma and only lateral surfaces with soft cuticle. Prodorsal shield without lateral projections, setae sc 1 represented by alveolus. Setae v 1 smooth, other dorsal setae weakly barbed; setae v 2, e, h 1, and h 2 weakly blunt-ended, other dorsal setae pointed; setae sc 2, c 1 and d with distinctly thickened basal part. Cupules not evident. Tergites C, D, and EF with pore-like structures typical for the genus. Pseudanal segment shorter than tergite H. Lengths of dorsal setae: v 1 37 (35–39), v 2 21 (17–22), sc 2 55 (53–59), c 1 45 (43-50), c 2 63 (57–68), d 47 (45–50), e 30 (29–36), f 44 (42–48), h 1 31 (28–34), h 2 29 (26–31). Distances between setae: v 1 –v 1 48 (46–52), v 2 –v 2 78 (61–80), sc 2 –sc 2 80 (80–84), c 1 – c 1 100 (99–110), c 1 – c 2 55 (55–74), d–d 92 (91–105), e–e 95 (89–100), f–f 115 (115–130), h 1 – h 1 63 (48–64), h 1 – h 2 20 (20–31).

Idiosomal venter (Figs 8, 11B, 12B, D). All ventral plates with numerous very small dimples. Setae 1 a, 2 a, 3 c, 4 b, 4 c, and ag 1 smooth, over ventral setae weakly barbed. Setae ps 1 weakly blunt-ended, other ventral setae pointed; all ventral setae with distinctly thickened basal part. Ap5 long, reaching beyond base of setae 4 a. Aggenital plate with three pairs of aggenital setae. Anal opening subterminal. Length of mid-sternal plate 80 (76–80), width 75 (62–75); ratio length/width 1.1–1.2. Lengths of ventral setae: 1 a 44 (43–47), 1 b 36 (35–39), 1 c 36 (35–43), 2 a 49 (46–51), 2 b 47 (46–54), 2 c 44 (42–48), 3 a 39 (37–42), 3 b 44 (43–48), 3 c 39 (36–42), 4 a 47 (46–51), 4 b 42 (41–44), 4 c 40 (35–42), ag 1 38 (36–42), ag 2 48 (46–53), ag 3 45 (44–53), ps 1 36 (35–38), ps 2 54 (53–58), ps 3 31 (30–42).

Legs (Figs 9, 10). Leg I (Fig. 9A): setae v’ of femur, k of tibia, s, pv’, pv”, and pl” of tarsus smooth, other leg setae (except eupathidia) weakly barbed; seta pl” of tarsus slightly thickened and flattened distally; setae l’, v’ of femur, k of tibia, and pv” of tarsus blunt-ended, other leg setae (except eupathidia) pointed; lengths of solenidia ω 1 11 (11–12), ω 2 9 (9–10), φ 1 13 (12–13), φ 2 10 (10–11); ω 1 and φ 1 digitiform, ω 2 and φ 2 baculiform. Leg II (Fig. 9B): solenidion ω 12 (12–13) digitiform, solenidion φ 10 (10–11) baculiform; seta tc’ of tarsus smooth, other leg setae weakly barbed; seta u’ of tarsus with slightly thickened and flattened tip; seta l’ of femur blunt-ended, other leg setae pointed. Leg III (Fig. 10A) similar in shape and length to leg II; solenidion φ 10 (10–11) baculiform; all leg setae barbed; seta l’ of genu blunt-ended, other leg setae pointed. Leg IV (Fig. 10B): solenidion φ 10 (10–11) baculiform; all leg setae barbed; setae l” of genu and p’ of tarsus blunt-ended, other leg setae pointed.

Type material. Female holotype, slide No. ZISP T-Ath-006, Sri Lanka (no more precise locality), on a beetle Bolboceras sp. Paratypes: 15 females, same data .

Type deposition. The holotype and four paratypes are deposited in the collection of the Zoological Institute of RAS, Saint Petersburg, Russia ; other paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia .

Differential diagnosis. The new species considerably differs from all described Athyreacarus species in having cheliceral stylets with a subapical tooth and the presence of scale-like microsculpture on tergites D, EF and H (both characters absent in all known Athyreacarus species).

Etymology. The name of the new species derives from the Latin words “ brevis ” meaning “ short ” and “ seta ” meaning “ bristle ” and refers to unusually short dorsal body setae of females of this species.