Sperchon (Sperchon) rubiscutellatus, K & K & K, 2022

K, Harry Smit, K, Vladimir Pešić & K, Mer Man Gurung, 2022, The water mite genus Sperchon Kramer, 1877 in Bhutan (Acari: Hydrachnidia: Sperchontidae), with the description of three new species, Acarologia 62 (3), pp. 754-762 : 755-758

Sperchon (Sperchon) rubiscutellatus sp. nov.

Zoobank: 54E9679A-AC65-4BBB-8947-608FA5C95BA8

( Figure 2 A-H)

Material examined — Holotype male, Khabab Chhu , Bhutan, 27.48492°N, 90.33490°E, 2500 m a.s.l., 14 May 2021, leg. M.M. Gurung (NBC) . Paratypes: seven males, five females, same data as holotype (NBC); five males, two females, same location as holotype, 7 Nov. 2021 (NBC); one male, Nika Chhu, Bhutan, 27.526008°N, 90.299471°E, 2609 m a.s.l., 10 May

2021, leg. M.M. Gurung (NBC); two males, Chendebji Chhu, 27.47692°N, 90.35265°E, 2483 m a.s.l., 8 Nov. 2021, leg. M.M. Gurung (NBC).

Other material – 4/5/0, Chuserbu Chhu, 27.502465°N, 90.317826°E, 2666 m a.s.l., 13 May 2021 ; 0/1/0, Chumpigang Chhu, 27.31608°N, 90.58071°E, 1018 m a.s.l., 2 Nov. 2021 ; 3/0/0, Rukhubju Chhu, 27.51174°N, 90.29711°E, 2587 m a.s.l., 5 Nov. 2021 ; 1/1/0, Chuserbu Chhu, 27.50246°N, 90.31782°E, 2666 m a.s.l., 6 Nov. 2021

Diagnosis — Dorsal platelets relatively large (length up to 160), with an unpaired central platelet (diameter 140); P2 with a large anteroventral extension with a stout seta, P4 ventrally with two stout setae lying relatively close to each other.

Description — Male: Integument papillate. Idiosoma dorsally 753 (570-778) long and 720 (583-729) wide, ventrally 818 (632-842) long. Dorsum with relatively large glandularia (length up to 160), reddish platelets (but yellowish to yellowish-brown in young specimens and in a few mature specimens) and three pairs of platelets without glandularia; preocularia on a small platelet, postocularia on a relatively large platelet; centrally with a large unpaired platelet, diameter 140 ( Figure 2A). Occasionally Dgl-3 fused with lateral platelet without glandularia ( Figure 2C). Gnathosoma stocky, 158 long. Venter with relatively large platelets. Cx-I medially separated ( Figure 2B), Cx-III witht a glandularium. Genital field with three pairs of acetabula, middle acetabula elongated; genital flap 194 long, medial margin with a row of setae ( Figure 2F). Excretory pore sclerotized. Length of P1-5: 28, 90, 109, 152, 35. P2 with an anteroventral extension and a stout seta, P4 ventrally with two stout, blunt setae ( Figure 2 D-E). Length of I-leg-4-6: 160, 180, 164. Length of IV-leg-4-6: 259, 251, 227. II-IV-leg with pectinate setae ( Figure 2H). Leg claws with three clawlets, the most ventral one blunt.

Female: Idiosoma dorsally 940 (612-846) long and 899 (632-818) wide, ventrally 980

(697-899) long. In most aspects similar to male. Central unpaired dorsal platelet smaller compared to male. Genital flap 203 long ( Figure 2G). Length of P1-5: 36, 130, 150, 208, 49. Palp as in male. Length of I-leg-4-6: 190, 212, 180. Length of IV-leg-4-6: 308, 283, 267. Legs as in male.

Etymology — Named for the red-coloured platelets.

Discussion — Sperchon gracilipalpis Lundblad, 1941 has more or less similar configuration of the dorsal platelets, but these platelets are much smaller compared to the new species. Moreover, the palp of S. gracilipalpis has P4 ventrally with only small setae, which are more separated from each other compared to the new species, and the integument is reticulated. Sperchon noshaqensis Imamura, 1966 has a more or less similar palp, but P3 is slenderer. Unfortunately, Imamura (1966) didn′t describe the dorsum of S. noshaqensis , but according to Pešić & Smit (2020) the dorsum is without sclerotized muscle attachment plates (although their assignment of their specimens is uncertain).