Athyreacarus magnificus, Khaustov & Frolov, 2019

Khaustov, Alexander A. & Frolov, Andrey V., 2019, Revision of the genus Athyreacarus (Acari: Athyreacaridae), Zootaxa 4647 (1), pp. 168-225 : 179-183

Athyreacarus magnificus sp. nov.

( Figs 8–14 )

Description. Female ( Figs 8–14 ). Body broadly fusiform. Length of idiosoma 455 (440–465), width 240 (235– 265).

Gnathosoma ( Figs 13C , 14E, F ). Gnathosomal capsule, excluding palps, almost oval, length 73 (71–75), width 77 (71–78). One pair of barbed, pointed or weakly blunt-ended cheliceral setae cha 41 (37–51). Postpalpal setae (pp) 12 (12–15) needle-like. Setae m 11 (10–11) smooth, blunt-ended, and n 65 (65–88) barbed, pointed. Setae dFe 18 (17–22) and dGe 28 (28–37) weakly barbed; setae dFe blunt-ended, dGe pointed. Tibial claw well-developed, slightly hooked with short basal projection ( Fig. 14F ).

Idiosomal dorsum ( Figs 8A , 11A , 12A, B , 13A , 14 AA–D). All dorsal shields with numerous relatively large sparsely distributed dimples ( Figs 12A, B ). Hysterosomal shields almost completely covering hysterosoma and only lateral regions with soft cuticle. Prodorsal shield without lateral projections, setae sc 1 vestigial ( Fig. 14B ). Setae v 2 smooth, other dorsal setae weakly barbed. Setae v 2 and e usually blunt-ended, other dorsal setae pointed. Cupules ia on tergite D, im, ip on tergite EF and ih on tergite H small, round. Cupules ih located dorsally, anterolaterally to bases of setae h 1. Pseudanal segment much shorter than tergite H. Lengths of dorsal setae: v 1 105 (105–115), v 2 19 (19–30), sc 2 170 (165–175), c 1 120 (110–135), c 2 185 (180–190), d 155 (150–160), e 32 (32–51), f 155 (155– 175), h 1 130 (130–140), h 2 110 (110–130). Distances between setae: v 1 –v 1 45 (44–47), v 2 –v 2 72 (71–74), sc 1 –sc 1 87 (86–92), sc 2 –sc 2 76 (76–82), c 1 – c 1 81 (81–94), c 1 – c 2 52 (52–65), d–d 94 (92–110), e–e 83 (80–89), f–f 95 (95–100), h 1 – h 1 66 (64–74), h 1 – h 2 21 (21–22).

Idiosomal venter ( Figs 8B , 11B , 12C, D , 13B, D, E ). All ventral plates with numerous rather large dimples ( Figs 12C, D ), dimples on aggenital and midsternal plates arranged slightly more densely than on other plates. All ventral setae weakly barbed. Setae 1 b, 2 c, 3 a, ag 1, ps 1 – ps 3 blunt-ended, other ventral setae pointed. Ap5 short, located near base of legs IV. Aggenital plate with three pairs of aggenital setae. Anal opening terminal. Length of mid-sternal plate 83 (80–93), width 80 (73–82); ratio length/width 1.0–1.2. Lengths of ventral setae: 1 a 56 (55–66), 1 b 15 (13–18), 1 c 37 (33–42), 2 a 77 (66–83), 2 b 55 (54–71), 2 c 14 (14–22), 3 a 28 (25–31), 3 b 58 (57–66), 3 c 41 (40–50), 4 a 48 (47–65), 4 b 62 (60–71), 4 c 40 (40–60), ag 1 28 (28–33), ag 2 66 (55–67), ag 3 75 (61–76), ps 1 61 (61–71), ps 2 65 (65–87), ps 3 36/64 (50–65).

Legs ( Figs 9 , 10 , 13F ). Length of legs: I 150 (140–150), II 145 (135–145), III 170 (160–175), IV 200 (190–210). Leg I ( Figs 9A , 13F ): setae v’ of trochanter, v’, l’, l” of femur, d, v”, k of tibia, s, pv’, pv”, and (pl) of tarsus smooth, other leg setae (except eupathidia) weakly barbed; setae 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; setae (pl) weakly spatulate apically; lengths of solenidia ω 1 13 (13–14), ω 2 11 (9–11), φ 1 11 (10–11), φ 2 10 (10); ω 1 and ω 2 digitiform, φ 1 and φ 2 baculiform. Leg II ( Fig. 9B ): solenidion ω 13 (13–14) digitiform, solenidion φ 10 (9–10) baculiform; setae l’ of femur, tc”, pv”, and (u) of tarsus smooth, other leg setae weakly barbed; setae l’ of femur and (tc) of tarsus blunt-ended, other leg setae pointed; setae (tc) of tarsus distinctly spatulate distally. Leg III ( Fig. 10A ) similar in shape and length to leg II; solenidion φ 10 (9–10) baculiform; setae l” of genu and pv’ of tarsus smooth, other leg setae weakly barbed; setae l” of genu and (tc) of tarsus blunt-ended; other leg setae pointed; setae (tc) of tarsus distinctly spatulate distally. Leg IV ( Fig. 10B ): solenidion φ 10 (9–10) baculiform; all leg setae weakly barbed; setae 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. 1735.1, BRASIL, Mato Grosso, Tangará da Serra, 19. IV.2010, E. Faccin leg., on a beetle Athyreus tuberifer Felsche. Paratypes: 4 females, same data; 23 females, BRASIL, Rondonia, Vilhena, 600 m., 1–2.XII.2012, N. Grohnert leg., on a beetle A. tuberifer ; two females, BRASIL, Minas Gerais, Viçosa, on a beetle A. tridens Laporte de Castelnau ; 10 females, BRASIL, Minas Gerais, Paracatu, on a beetle A. tridens ; 3 females, BRASIL, Distrito Federal, Brasilia, III.2001, N. Degallier leg., on a beetle A. brasilicus Howden & Martinez ; 7 females, BRASIL, Mato Grosso, Diamantino, IV.2014, M.E. Maldaner leg., on a beetle A. brasilicus ; 4 females, BRASIL, Distrito Federal, I.1961, A.B. Guimaraes leg., on a beetle A. hemisphaericus Boucomont ; 4 females, BRASIL, Randonia, Vilhena, 29–31. III.2013, N. Grohnert leg., on a beetle A. hemisphaericus .

Type deposition. The holotype and seven 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 ; 40 paratypes are deposited in the collection of the Tyumen State University Museum of Zoology , Tyumen, Russia ; 10 paratypes are deposited in the collection of the Zoological Institute of RAS, Saint Petersburg, Russia .

Differential diagnosis. The new species is very similar to A. variabilis sp. nov. and A. similis sp. nov. by the absence of setae chb, presence of three pairs of aggenital setae, setae sc 1 vestigial, and setae c 1 well developed. The new species differs from A. variabilis and A. similis by distally spatulate setae pl’ on tarsus I and tc’ on tarsi II and III (vs. pointed in A. variabilis and A. similis ). The new species differs from A. variabilis by the absence of subcuticular reticulation on prodorsal shield and tergite C (vs. weak subcuticular reticulation present on prodorsal shield and tergite C in A. variabilis ), and sparsely distributed but relatively large dimples on idiosomal plates (vs very small, densely distributed dimples on idiosomal plates in A. variabilis ). The new species differs from A. similis by its larger idiosomal length (440–465 in A. magnificus vs 320–345 in A. similis ), setae tc” on tarsi II and III and tc’ on tarsus IV distinctly spatulate (vs pointed in A. similis ), and median ends of apodemes 3 and 4 clearly separated (vs. median ends of apodemes 3 and 4 almost connected in A. similis ).

Etymology. The name of new species derived from Latin word “ magnificus ” meaning “ magnificent ” and refers to the large and impressive body size of the new species, which is only slightly smaller than A. grandis sp. nov.

Figures

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

FIGURE 9. Athyreacarus magnificus sp. nov., female: A—left leg I in dorsal view, B—left leg II in dorsal view.

FIGURE 10. Athyreacarus magnificus sp. nov., female: A—left leg III in dorsal view, B—left leg III in dorsal view.

FIGURE 11. Phase-contrast micrographs of Athyreacarus magnificus sp. nov., female: A—general aspect dorsally, B—general aspect ventrally.

FIGURE 12. Phase-contrast micrographs of Athyreacarus magnificus 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 13. SEM micrographs of Athyreacarus magnificus sp. nov., female: A—general aspect dorsally, B— general aspect ventrally, C—gnathosoma in ventral view, D—anterior sternal plate, E—opisthosoma in ventral view, F—tibia and tarsus of leg I in dorsal view.

FIGURE 14. SEM micrographs of Athyreacarus magnificus sp. nov., female:A—prodorsum, B— left part of prodorsal shield, C—metapodosoma in dorsal view, D—tergites D, EF, H and pseudanal segment in dorsal view, E—gnathosoma in lateroventral view, F—distal part of gnathosoma.