Athyreacarus brevisetosus, Khaustov & Frolov, 2020

Khaustov, Alexander A. & Frolov, Andrey V., 2020, First record of Athyreacaridae (Acari: Heterostigmata) from Asia with description of two new species of Athyreacarus from India and Sri Lanka, Zootaxa 4779 (2), pp. 260-272 : 267-270

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.

Figures

FIGURE 8. Athyreacarus brevisetosus sp. nov., female:A—dorsum of body, B—venter of body. Legs omitted.

FIGURE 9. Athyreacarus brevisetosus sp. nov., female:A—right leg I, dorsal aspect, B—right leg II, dorsal aspect.

FIGURE 10. Athyreacarus brevisetosus sp. nov., female: A—right leg III, dorsal aspect, B—right leg III, dorsal aspect.

FIGURE 11. DIC micrographs of Athyreacarus brevisetosus sp. nov., female: A—general aspect dorsally, B—general aspect ventrally.

FIGURE 12. DIC micrographs of Athyreacarus brevisetosus sp. nov., female:A—prosoma, dorsal aspect, B—prosoma, ventral aspect, C—hysterosoma, dorsal aspect, D—hysterosoma, ventral aspect, E—right part of tergite EF, F—gnathosoma with focus on distal part.