Athyreacarus latus, Khaustov & Frolov, 2019

Khaustov, Alexander A. & Frolov, Andrey V., 2019, Revision of the genus Athyreacarus (Acari: Athyreacaridae), Zootaxa 4647 (1), pp. 168-225 : 203-206

Athyreacarus latus sp. nov.

( Figs 38–42 )

Description. Female ( Figs 38–42 ). Body oval. Length of idiosoma 435 (415), width 305 (285).

Gnathosoma . Gnathosomal capsule, excluding palps, almost oval, length 62 (60), width 65 (64). Two pairs of barbed, blunt-ended cheliceral setae cha 29 (26) and chb 25 (19). Postpalpal setae (pp) 5 (5) needle-like. Setae m 11 (11) and n 57 (50) weakly barbed; setae m blunt-ended, n pointed. Setae dFe 13 (14) and dGe 31 (30) barbed; dFe blunt-ended, dGe pointed. Tibial claw small, slightly hooked with short basal projection.

Idiosomal dorsum ( Figs 38A , 41A , 42A, B ). All dorsal shields with numerous large sparsely distributed dimples ( Figs 42A, B ). Hysterosomal shields wide, completely covering hysterosoma. Prodorsal shield without lateral projections. Setae sc 1 and their alveoli absent. All dorsal setae weakly barbed. Setae c 2 and f pointed, other dorsal setae blunt-ended. Cupules and pore-like structures on hysterosomal tergites not evident. Pseudanal segment much shorter than tergite H. Lengths of dorsal setae: v 1 44 (32), v 2 13 (12), sc 2 155 (155), c 1 10 (18), c 2 165 (165), d 24 (21), e 14 (16), f 160 (160), h 1 135 (115), h 2 29 (28). Distances between setae: v 1 – v 1 53 (54), v 2 –v 2 85 (80), sc 2 –sc 2 130 (120), c 1 – c 1 135 (125), c 1 – c 2 75 (75), d–d 150 (135), e–e 165 (150), f–f 175 (165), h 1 – h 1 92 (82), h 1 – h 2 23 (20). Idiosomal venter ( Figs 38B , 41B , 42C, D ). All ventral plates with numerous large dimples ( Fig. 42C, D ). Setae 3 a smooth, other ventral setae weakly barbed. Setae 2 c, 4 c and ps 3 blunt-ended, other ventral setae pointed. Ap5 long, reaching beyond bases of setae 4 a. Aggenital plate with two pairs of aggenital setae. Anal opening ventral. Length of mid-sternal plate 70 (61), width 50 (46); ratio length/width 1.3–1.4. Lengths of ventral setae: 1 a 52 (51), 1 b 22 (18), 1 c 21 (21), 2 a 75 (53), 2 b 43 (41), 2 c 24 (26), 3 a 19 (18), 3 b 59 (51), 3 c 32 (31), 4 a 40 (39), 4 b 47/50 (48), 4 c 22 (21), ag 1 36 (31), ag 2 56 (48), ps 1 90/95 (93), ps 2 110 (110), ps 3 60 (43/50).

Legs ( Figs 39 , 40 ). Length of legs: I 155 (160), II 160 (150), III 180 (180), IV 215 (200). Leg I ( Fig. 39A ): tarsal claw very thick; setae v’ of trochanter, d, v’ of femur, d, l’, v’, k of tibia, pl’, s, and pv” of tarsus smooth, other leg setae (except eupathidia) weakly barbed; setae v’ of trochanter, l’, l”, v’ of femur, d, v’ of genu, v’, k of tibia, and pv” of tarsus blunt-ended, other leg setae pointed; lengths of solenidia ω 1 16 (15), ω 2 12 (10), φ 1 12 (12), φ 2 12 (10); ω 1 digitiform, ω 2, φ 1 and φ 2 baculiform. Leg II ( Fig. 39B ): solenidion ω 14 (13) digitiform, solenidion φ 10 (10) baculiform; all leg setae barbed; setae v’ of trochanter and l’ of femur, blunt-ended; other leg setae pointed. Leg III ( Fig. 40A ) similar in shape and length to leg II: solenidion φ 10 (10) baculiform; all leg setae barbed; setae v’ of femur and l” of genu blunt-ended; other leg setae pointed. Leg IV ( Fig. 40B ): solenidion φ 10 (10) baculiform; all leg setae barbed; setae v’ of femur, l” of genu, and p’ of tarsus blunt-ended, other leg setae pointed.

Type material. Female holotype, slide No. ZISP T-Ath-002, no locality data, on a beetle Athyreus cf. bifurcatus MacLeay. Paratype: 1 female, same data.

Type deposition. The holotype is deposited in the collection of the Zoological Institute of RAS, Saint Petersburg, Russia ; one paratype is deposited in the collection of the Tyumen State University Museum of Zoology , Tyumen, Russia .

Differential diagnosis. The new species is most similar to A. ovalis by the presence of two pairs of cheliceral setae, absence of cupules and pore-like structures on the hysterosomal tergites and thick apodemes 1. The new species differs from A. ovalis by the complete absence of setae sc 1 (vs alveoli of setae sc 1 present in A. ovalis ), very short and blunt-ended setae c 1 and d (vs very long and pointed in A. ovalis ), and presence of only two pairs of aggenital setae (vs three pairs in A. ovalis ).

Etymology. The name of new the species derives from Latin word “ latus ” meaning “ wide ” and refers to very wide body of a new species.

Remarks. According to Howden & Martínez (1977), Athyreus bifurcatus is distributed in Brazil (as far north as the state of Mato Grosso), Paraguay and northern Argentina (Misiones Province). The host specimen lacks any locality data but we think it originated from either Paraguay or south-eastern Brazil as did most of the other older specimens of Bolboceratinae in the ZIN collection.

Figures

FIGURE 38. Athyreacarus latus sp. nov., female: A—dorsum of body, B—venter of body.

FIGURE 39. Athyreacarus latus sp. nov., female: A—left leg I in dorsal view, B—left leg II in dorsal view.

FIGURE 40. Athyreacarus latus sp. nov., female: A—left leg III in dorsal view, B—right leg III in dorsal view.

FIGURE 41. Phase-contrast micrographs of Athyreacarus latus sp. nov., female: A—general aspect dorsally, B—general aspect ventrally.

FIGURE 42. Phase-contrast micrographs of Athyreacarus pusillus sp. nov., female: A—prodorsal shield and anterior part of hysterosoma in dorsal view, B—posterior part of hysterosoma in dorsal view, C—anterior sternal plate, and coxal fields III, D—hysterosoma in ventral view.