Protoribates dentatus ( Berlese, 1883 )

Chen, Shujing Xu Yannan & Chen, Jun, 2020, New species and records of oribatid mites of the genus Protoribates (Acari Oribatida, Haplozetidae) from China, Zootaxa 4772 (3), pp. 469-511 : 503-506

Protoribates dentatus ( Berlese, 1883)

( Figs 25–26 )

Oribates dentatus Berlese, 1883: 3 .

Protoribates dentatus ( Berlese, 1883) : Berlese, 1908: 1; Weigmann et al., 1993: 39–55, figs I–VIII; Seniczak et al., 2018: 613–627, figs 1–12; Ermilov & Liao, 2018: 1019; Ermilov & Leong, 2018: 1769.

Peloribates vastus Mihelčič, 1956: 20–21 , fig. 14.

Protoribates vastus ( Mihelčič, 1956) : Pérez-Iñigo, 1974: 397–398, fig. 24; Subías, 2004: 206 (synonymy).

Xylobates vastus ( Mihelčič, 1956) : Pérez-Iñigo, 1993: 209, fig. 76A.

Supplementary description. Body length 480–650, width 275–382. Body color brown. Body surface punctate. Lateral parts of prodorsum between sublamellae and acetabula I, II microgranulate.

Prodorsum. Rostrum broadly rounded. Lamellae located dorsolaterally, half as long as prodorsum (measured in lateral view). Sublamellae about half as long as lamellae. Sublamellar porose areas (30 × 16) oval, located very near to sublamellae. Rostral (52–55), lamellar (92) and interlamellar (100–113) setae setiform, barbed. Lamellar setae inserted on lamellar ends. Bothridial setae (120–130) with long stalk and short, slightly unilaterally dilated, apically pointed, barbed head. Exobothridial setae (25) thin, barbed. Dorsophragmata comparatively short, longitudinally elongated, directed posteromedially. Tutorium ridge-like.

Notogaster. Anterior notogastral margin convex medially. Pteromorphs with distinct hinges. Ten pairs of notogastral setae minute (5–8), thin, smooth. Four pairs of rounded porose areas, similar in size, Aa (13–16) relatively larger than A1, A2 and A3 (9–15), A2 occasionally divided into two closely situated pores on one side (CYN-18- 156). Distance between porose areas A1–A1 subequal to A2–A2. Setae lp inserted anteromedially to A1. All lyrifissures and opisthonotal gland openings clearly visible.

Gnathosoma . Subcapitulum longer than wide (130–137 × 87–92). Subcapitular setae (a, 19–20; h, 27–37; m, 12) setiform, m thinnest.

Epimeral and lateral podosomal regions. Epimeral setal formula: 3-1-3-2. Epimeral setae setiform, thin, 1b, 3b and 3c (25–37) longer than others (10–19). Circumpedal carinae of medium size, directed to pedotecta II, but not reaching it.

Anogenital region. One pair of genital setae long (g 1, 28), barbed. Four pairs of genital (g 2 –g 5, 8–11), one pair of aggenital (12–17), two pairs of anal (16–25) and two pairs of adanal (ad 2, 20–24; ad 3, 17–18) setae setiform, thin, smooth, adanal setae ad 1 (51–62) longer than ad 2 and ad 3, barbed. Adanal setae ad 1 in posterior, ad 2 in lateral, ad 3 in anterior positions. Adanal lyrifissures located close and parallel to anal aperture.

Legs. Monodactylous or heterotridactylous, median claw thicker than laterals, barbed on dorsal side. Femora II spur-like sharpened ventroanteriorly. Femora I–IV and trochanters III, IV with distinctly developed dorsoparaxial porose area. Tibiae I, II with ventrobasal tooth. 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.

Material examined. Two females (one in alcohol and one on permanent slide, CYN-18-140): China, Sichuan, Pengzhou, Dabaoshan Town , Longcaogou , 31°22′67.57″N, 103°75′50.89″E, 1123 m a.s.l., litter under Ginkgo biloba L., 11.VIII.2018; one male (in alcohol, CYN-18-141): same place as CYN-18-140, litter under arbor, 11.VIII.2018; one male (on permanent slide, CYN-18-149): China, Sichuan, Pengzhou , Xiaoyudong Town , 31°18′88.17″N, 103°75′40.75″E, 956 m a.s.l., litter, 12.VIII.2018; one male (on permanent slide, CYN-18-150): same place as CYN- 18-149, litter, 12.VIII.2018; three specimens (two males in alcohol; one female on permanent slide, CYN-18-156): same place as CYN-18-149, 31°18′04.98″N, 103°73′44.09″E, 1131 m a.s.l., mosses, 13.VIII.2018. All specimens above were collected by Yannan Chen. One female (on permanent slide, LK-14-008): China, Guangxi, Nanning, Liangfengjiang National Forest Park, Bodhi Villa , 22°43′31.50″N, 108°17′02.76″E, 70 m a.s.l., litter, 16.IV.2014; one male (on permanent slide, LK-14-009): same place as LK-14-008, 22°43′29.71″N, 108°17′06.03″E, 57 m a.s.l., litter under bamboo forest, 16.IV.2014. Both the above were collected by Kang Li.

Distribution. China (Guangxi, Sichuan, Macao, Taiwan), Holarctic, Oriental and Melanesia ( Fiji I.).

Remarks. Weigmann et al. (1993) redescribed the species in detail according to the specimens in Berlese’s collection and from Slovakia. In that paper, they stated that the claws varied: leg I is usually monodactylous, others heterotridactylous, but mono-, bi- or tridactylous occurs occasionally on all legs. Seniczak et al. (2018) described and illustrated the morphological ontogeny of the species according to the specimens from Greece and showed that the number of claws of adults varies on all leg tarsi, and the most common formula is 1-3-3-3.

We examined ten specimens in China, the claw formula of eight of them is 1-1-1-1 (five males and three females from Sichuan) ; one is 1-3-3-3 (female from Guangxi); one is 3-3-3-3 (male from Guangxi). The number of claws varies.

After examining the specimens, we did’t see the epimeral setae 4c, which is present in the specimens of Weigmann et al. (1993) and Seniczak et al. (2018) described.

Figures

FIGURE 25. Protoribates dentatus (Berlese, 1883), adult. A. dorsal view; B. bothridial setae. Scale bars: A=100 μm, B=30 μm.

FIGURE 26. Protoribates dentatus (Berlese, 1883), adult. A. ventral view. Scale bar 100 μm.