Athyreacarus vazdemelloi, Khaustov & Frolov, 2019

Khaustov, Alexander A. & Frolov, Andrey V., 2019, Revision of the genus Athyreacarus (Acari: Athyreacaridae), Zootaxa 4647 (1), pp. 168-225 : 196-199

Athyreacarus vazdemelloi sp. nov.

( Figs 26–32 )

Description. Female ( Figs 26–32 ). Body broadly fusiform. Length of idiosoma 430 (420–450), width 245 (240– 255).

Gnathosoma ( Figs 32 A–C). Gnathosomal capsule, excluding palps, almost oval, length 66 (64–68), width 73 (71–74). One pair of barbed, blunt-ended cheliceral setae cha 37 (35–38). Basal part of stylophore with distinct small depression ( Fig. 32A ). Postpalpal setae (pp) 12 (12–13) needle-like. Setae m 9 (9–10) smooth, blunt-ended, and n 65 (63–75) barbed, pointed. Setae dFe 23 (18–24) and dGe 36 (35–39) barbed; setae dFe blunt-ended, dGe pointed. Tibial claw slightly hooked with short basal projection Fig. 32B ).

Idiosomal dorsum ( Figs 26A , 29A , 30A, B , 31 A–C). All dorsal shields with numerous large and small sparsely distributed dimples ( Figs 30A, B ). Hysterosomal shields almost completely covering hysterosoma and only lateral surfaces with soft cuticle. Prodorsal shield without lateral projections, setae sc 1 microsetae ( Fig. 31C ). Setae c 1 smooth, other dorsal setae distinctly barbed. Setae c 1, v 2 and e weakly blunt-ended, other dorsal setae pointed. Cupules ia on tergite D and ih on tergite H small, round. Cupules im and ip on tergite EF not evident. Cupules ih located dorsally, anterolaterally to bases of setae h 1. Pseudanal segment shorter than tergite H. Lengths of dorsal setae: v 1 105 (93–105), v 2 18 (18–20), sc 2 170 (170–175), c 1 18 (15–18), c 2 170 (170–190), d 170 (94–180), e 19 (18–23), f 160 (160–170), h 1 130 (130–135), h 2 63 (62–66). Distances between setae: v 1 –v 1 51 (50–52), v 2 –v 2 100 (100–105), sc 1 –sc 1 110 (110–115), sc 2 –sc 2 94 (93–98), c 1 – c 1 76 (75–83), c 1 – c 2 53 (52–55), d–d 105 (105–110), e–e 90 (87–94), f–f 100 (97–105), h 1 – h 1 72 (72–78), h 1 – h 2 17 (14–18).

Idiosomal venter ( Figs 26B , 29B , 30C, D , 31D ). All ventral plates with numerous intermixed large and small dimples ( Figs 30C, D ), dimples on aggenital plate arranged slightly more densely than on other plates. Setae 1 b, 2 b, 3 a, 3 c, 4 a, and 4 c smooth, over ventral setae weakly barbed. Setae 1 b, 2 c, 3 a, 4 c, ag 1, and ps 2 weakly blunt-ended, other ventral setae pointed. Ap5 short, located near base of legs IV. Aggenital plate with two pairs of aggenital se- tae. Anal opening terminal. Length of mid-sternal plate 64 (63–74), width 63 (62–70); ratio length/width 1.0–1.1. Lengths of ventral setae: 1 a 46 (46–49), 1 b 21 (19–22), 1 c 24 (24–26), 2 a 70 (68–70), 2 b 43 (41–43), 2 c 17 (17–18), 3 a 18/21 (18–22), 3 b 42/50 (42–51), 3 c 31 (30–34), 4 a 46 (41–46), 4 b 43 (41–60), 4 c 24 (24–39), ag 1 25 (25–27), ag 2 44 (44–48), ps 1 85 (85–87), ps 2 45 (45–51), ps 1 28/36 (28–37).

Legs ( Figs 27 , 28 , 32D ). Length of legs: I 150 (150–165), II 150 (145–155), III 165 (165–180), IV 200 (200– 210). Leg I ( Fig. 27A ): setae v’ of trochanter, v’, l’, l” of femur, l” of genu, k of tibia, s, pv’, pv”, and pl” of tarsus smooth, other leg setae (except eupathidia) weakly barbed; setae v’ of trochanter, l’, l”, v’ of femur, v’, l” of genu, v’, l” and k of tibia, and pv” of tarsus blunt-ended, other leg setae (except eupathidia) pointed; lengths of solenidia ω 1 13 (13–14), ω 2 11 (10–12), φ 1 12 (11–12), φ 2 10 (10); ω 1 and φ 1 digitiform, ω 2 and φ 2 baculiform. Leg II ( Figs 27B , 32D ): solenidion ω 14 (14–15) digitiform, solenidion φ 11 (10–11) baculiform; setae l’ of femur, l’ and v’ of genu smooth, other leg setae weakly barbed; setae v’ of trochanter, l’ of femur and tc” of tarsus blunt-ended, other leg setae pointed; seta tc” of tarsus weakly spatulate distally ( Fig. 32D ). Leg III ( Fig. 28A ) similar in shape and length to leg II; solenidion φ 10 (10–11) baculiform; all leg setae barbed; setae v’ of femur, l’ of genu and tc” of tarsus blunt-ended, other leg setae pointed; seta tc” of tarsus weakly spatulate distally. Leg IV ( Fig. 28B ): solenidion φ 10 (10–11) baculiform; all leg setae barbed; setae v’ of trochanter, v’ of femur, v’, l” of genu, p’ and tc’ of tarsus blunt-ended, other leg setae pointed; seta tc’ of tarsus weakly spatulate distally.

Type material. Female holotype, slide No. 1737.1, BRAZIL, Minas Gerais, Cordisburgo, Fazenda Pontinha, XII.1997, F.Z. Vaz-de-Mello leg., on a beetle Parathyreus rectus Howden. Paratypes: 11 females, same data.

Type deposition. The holotype and three paratypes are deposited in the collection of UNESP — Universidade Estadual Paulista, Department of Zoology and Botany, 15054—000 São José do Rio Preto—SP, Brazil ; five paratypes are deposited in the collection of the Tyumen State University Museum of Zoology , Tyumen, Russia ; three paratypes are deposited in the collection of the Zoological Institute of RAS, Saint Petersburg, Russia .

Differential diagnosis. The new species is most similar to A. pusillus sp. nov. by the absence of setae chb, presence of two pairs of aggenital setae, and setae c 1 well developed. The new species differs from A. pusillus by having a distinctly larger idiosoma (420–450 in A. vazdemelloi vs 240–270 in A. pusillus ), most dorsal and ventral idiosomal setae pointed (vs. most dorsal and ventral idiosomal setae blunt-ended in A. pusillus ), and setae c 2 almost 10 times longer than c 1 (vs setae c 2 less than 3 times longer than c 1 in A. pusillus ).

Etymology. The new species is named after Fernando Vaz-de-Mello (CEMT), the leading scarab beetle researcher in Brazil.

Figures

FIGURE 26. Athyreacarus vazdemelloi sp. nov., female: A—dorsum of body, B—venter of body.

FIGURE 27. Athyreacarus vazdemelloi sp. nov., female: A—right leg I in dorsal view, B—right leg II in dorsal view.

FIGURE 28. Athyreacarus vazdemelloi sp. nov., female: A—right leg III in dorsal view, B—right leg III in dorsal view.

FIGURE 29. Phase-contrast micrographs of Athyreacarus vazdemelloi sp. nov., female: A—general aspect dorsally, B—general aspect ventrally.

FIGURE 30. Phase-contrast micrographs of Athyreacarus vazdemelloi sp. nov., female: A—prodorsal shield, B—right half of tergites D and EF, C—anterior sternal plate, D—aggenital and midsternal plates and part of coxal fields IV.

FIGURE 31. SEM micrographs of Athyreacarus vazdemelloi sp. nov., female: A—general aspect dorsally, B— prosoma in dorsal view, C—right part of prodorsal shield, D—general aspect ventrally.

FIGURE 32. SEM micrographs of Athyreacarus vazdemelloi sp. nov., female:A—gnathosoma in dorsal view, B— gnathosoma in ventral view, C—anterior part of gnathosoma in ventral view, D—tibia and tarsus II in dorsal view.