Indoribates (Indoribates) subiasi sp. nov.

(Figs 1, 2)

Type material

Holotype: male (in 100% alcohol, XSJ-19-032): China, Hunan, Yongshun County, Xiaoxi Village, Xiaoxi National Nature Reserve, 28°47′56″N, 110°16′17″E, ca. 580 m a.s.l., litter under the arbor, 27.IV.2019.

Paratypes: seven females and fourteen males, in alcohol, same data as the holotype .

Other (non-type) material

Five specimens (three females and two males in alcohol, XSJ-19-027): same locality as the holotype, 28°47′56″N, 110°15′47″E, ca. 560 m a.s.l., litter under pine trees, 27.IV.2019; two males (in alcohol, XSJ-19-028): same locality as the holotype, N 28°47′52″N, 110°15′58″E, ca. 630 m a.s.l., litter under the bush, 27.IV.2019; one male (in alcohol, XSJ-19-030): same locality as the holotype, 28°47′54″N, 110°16′10″E, ca. 650 m a.s.l., litter under the bush, 27.IV.2019; five specimens (four females and one male in alcohol, XSJ-19-009): China, Hunan, Zhangjiajie, Wulingyuan District, Wenfeng Village, 29°20′07″N, 110°35′29″E, ca. 430 m a.s.l., litter under pine trees by the river, 24.IV.2019 ; one female (in alcohol, XSJ-19-011): same locality as the above, 29°19′51″N, 110°36′E, ca. 410 m a.s.l., litter under small broad-leaved trees, 24.IV.2019; one male (in alcohol, XSJ-19-012): same locality as the above, 29°19′33″N, 110°36′15″E, ca. 460 m a.s.l., litter in the grass under small broad-leaved trees, 24.IV.2019; one female (in alcohol, XSJ-19-035): China, Hubei, Xuan’en County, Changtanhe Town, Lianghekou Village, 29°59′13″N, 109°43′51″E, ca. 1140 m a.s.l., litter under the coniferous and broad-leaved trees near the road, 30.IV.2019 ; one female (on permanent slide, ZLH-13-084): China, Guangdong, Taishan, Xiachuan Island, Guanyin Mountain, 21°38′23″N, 112°35′42″E, ca. 100 m a.s.l., litter under the arbor, 21.X.2013 ; two specimens (one female and one male in alcohol, CJ-14-101): China, Jiangxi, Lushan, Sandiequan, 29°33′35″N, 116°00′40″E, ca. 990 m a.s.l., mosses on stone, 6.VIII.2014 ; two specimens (one female and one male in alcohol, ZLH-20-177): China, Henan, Shangcheng county, Suxianshi Town, Xihe Village, Dabie Mountain Nature Reserve, West River Scenic Area, Huatuo Valley, 31°43′28″N, 115°32′24″E, ca. 470 m a.s.l., litter under coniferous forest, 17.VII.2020 ; one female (in alcohol, ZLH-20-182): same locality as the above, ca. 500 m a.s.l., litter under broad-leaved forest, 17.VII.2020; thirty five specimens (sixteen females and nineteen males in alcohol, ZLH-21-089): China, Anhui, Lu’an, Huoshan County, Taiyang Village, Baimajian, 31°7′51″N, 116°9′51″E, ca. 700 m a.s.l., litter under coniferous and broad-leaved trees, 12.VIII.2021 .

Diagnosis

Body length: 490–640. Rostrum round. Rostral, lamellar and interlamellar setae long, setiform, barbed; ro shortest; in longest. Bothridial seta long, setiform, barbed. Tutorium long, with tooth distally. Ten pairs of notogastral setae setiform, thin, smooth, c medium-sized, others short. Four pairs of saccules with slightly elongated channels. Five pairs of genital setae. Three pairs of aggenital setae. Leg I monodactylous, legs II to IV heterobidactylous.

Description

Measurements. Body length: 530 (holotype), 490–640 (paratypes); notogaster width: 320 (holotype), 320–440 (paratypes). No differences between males and females in body size.

Integument. Body color light brown to brown.Cuticle densely microfoveolate (visible under high magnification). Lateral side of body with microgranulate cerotegument.

Prodorsum (Fig. 1A, C). Rostrum rounded. Lamella about one-half length of prodorsum. Sublamella short. Sublamellar porose area oval or slightly rounded (7–10 × 8–13), located near to sublamella. Tutorium long, with tooth distally. Rostral (60–70) and lamellar (92–100) setae, setiform, barbed; interlamellar seta (110–120) setiform, slightly barbed; insertion of ro mostly close to the tooth of tutorium, occasionally far from it on one side; le inserted at end of lamella. Bothridial seta (130–165) setiform, unilaterally barbed. Exobothridial seta (25–35) setiform, thin, barbed. Dorsosejugal porose area elongate oval.

Notogaster (Fig. 1A, C). Anterior notogastral margin convex medially. Ten pairs of setae setiform, smooth, c (80–98) distinctly longer than others (25–50). Four pairs of saccules with slightly elongated channels. Opisthonotal gland opening and all lyrifissures distinct.

Gnathosoma (Fig. 2E–G). Subcapitulum size: 112–125 × 95–98. Subcapitular setae (a: 20–25; m: 30–40; h: 25–38) setiform, slightly barbed. Both adoral setae (12–15) setiform, densely barbed. Palp (85–90) with typical setation 0-2-1-3-9(+ω). Postpalpal setae (5–6) spiniform, smooth. Chelicera (132–135) with two setiform, barbed setae (cha: 30–48; chb: 28–30).

Epimeral and lateral podosomal regions (Fig. 1B, C). Epimeral setal formula: 3-1-3-3. All epimeral setae setiform, thin, roughened or slightly barbed, 1b (28–30), 3b (25–35) and 3c (28–40) longer than others (12–25). Discidium rectangular in lateral view. Circumpedal carina distinct, directed to pedotectum II.

Anogenital region (Fig. 1B, C). Five pairs of genital setae (12–20), three pairs of aggenital setae (12–18), two pairs (occasionally three setae on one plate) of anal setae (20–28), and three pairs of adanal seta (20–30) setiform, smooth. Adanal lyrifissure close and parallel to anal plate.

Legs (Fig. 2A–D). Leg I monodactylous, legs II to IV bidactylous, one claw slightly barbed on dorsal side, thicker than the other one. Dorsoparaxial porose area on femora I–IV and on trochanters III, IV, and ventrodistal porose area on tibiae I–IV and proximoventral porose area on tarsi I–IV poorly visible. Formulas of leg setation and solenidia: I (1-5-3-4-20) [1-2-2], II (1-5-3-4-15) [1-1-2], III (2-3-1-3-15) [1-1-0], IV (1-2-2-3-12) [0-1-0]; homology of setae and solenidia indicated in Table 1.

Note: Roman letters refer to normal setae, and Greek letters to solenidia (except ɛ = famulus). A single quotation mark (’) designates setae on the anterior side and a double quotation mark (”) setae on the posterior side of a given leg segment. Parentheses refer to a pair of setae.

Etymology The specific name “ subiasi ” is in honor of Luis S. Subías for his contribution to the study of oribatid mites.

Distribution

This species is known from Anhui, Guangdong, Henan, Hubei, Hunan and Jiangxi provinces in the central and southern part of China.

Remarks

The new species is distinguished from all representatives of the subgenus Indoribates by the presence of monodactylous leg I and heterobidactylous legs II to IV. Only one species, Indoribates (Indoribates) bayartogtokhi (Ermilov, Sandmann & Scheu, 2019), owns bidactylous legs. The new species differs from I. (I.) bayartogtokhi by having monodactylous leg I (versus bidactylous leg I); three pairs of aggenital setae (versus one pair); setiform bothridial seta (versus spindle-form bothridial seta); interlamellar seta longer than rostral setae (versus interlamellar seta shorter than rostral setae).

By having three pairs of aggenital setae, setiform bothridial seta and medium-sized notogastral setae, the new species is morphologically similar to Indoribates (Indoribates) bicarinatus Ermilov & Anichkin, 2014 . However, the new species differs from the latter by having heterobidactylous legs II to IV (versus monodactylous leg II to IV); lacking longitudinal ridges on anal plates (versus have longitudinal ridges on anal plates); notogastral setae c longer than rostral setae (versus notogastral setae c similar to or shorter than rostral setae).