Scutacarus sibiriensis Khaustov, 2015, sp. nov.

Scutacarus sibiriensis sp. nov.

(Figs. 13–15)

Description. FEMALE. Length of idiosoma 160 (145–160), width 165 (150–165). Gnathosoma similar to that of S. moseri sp. nov. Idiosomal dorsum (Fig. 13 A, 14A): Prodorsum completely covered by tergite C, with 2 pairs of smooth needle-like setae v 2 and sc 2, 1 pair of barbed capitate trichobothria (Fig. 14 A), and 1 pair of oval stigmata situated ventrally (Figs. 13 B). All dorsal shields with numerous small dimples. Setae e and h 2 vestigial, setae f and h 1 smooth, needle-like, other dorsal setae distinctly barbed and blunt-ended. Cupules ia on tergite D and ih on tergite H large and round. Tergites EF and H each with 1 pair of oval porous fields situated anteriorly to setae f and h 1. Lengths of dorsal setae: c 1 28 (26 – 28), c 2 24 (22 – 24), d 33 (28–33), f 7 (7), h 1 8 (9). Distances between setae: c 1– c 1 47 (45–47), d–d 84 (79–84), f–f 85 (75–85), h 1– h 1 41 (37–41). Idiosomal venter (Fig. 13 B): All ventral plates with numerous small dimples. Ap1 well-developed and joined with appr, ap2 thin, w-shaped, joined with appr; apsej well-developed and joined with appr. Sta absent. Apodemes 3 absent, ap4 short, joined with appo. Apodemes 5 joined with appo, diffuse. Setae 2 b slightly thickened, smooth, blunt-ended, setae 4 a smooth, pointed, situated anteriorly to level of setae 4 b, setae ps 3 short, smooth, blunt-ended. Other ventral setae sparsely barbed. Secondary transverse sclerotized line on poststernal plate absent. Ags complicate, consists of median tongue-like elongation connected with sclerotized oval structure ring laterally with tube-like sclerites, pgs large, triangular. Lengths of ventral setae: 1 a 28 (24–28), 1 b 20 (19–20), 2 a 19 (19–21), 2 b 17 (16–17), 3 a 23 (21–23), 3 b 31 (28–31), 3 c 26 (22–26), 4 a 13 (11–13), 4 b 29 (26–29), 4 c 28 (19–28), ps 1 20 (17–20), ps 2 19 (16–19), ps 3 4 (4). Legs (Figs. 14, 15). Leg setation as in S. heterotrichus sp. nov. except absence of seta v” of femur I. Leg I (Figs. 14 B). Tibiotarsus with large tarsal claw, tapered at its end. Seta k smooth, blunt-ended, eupathidion tc” situated on long pinnaculum; tc’ on short protuberance. Lengths of solenidia: ω 1 9 (7–9)> ω 2 6 (4–6) = φ 1 6 (5–6)> φ 2 5 (4–5); ω 2 and φ 2 baculiform, φ 1 clavate, ω 1 finger-shaped. Seta dFe thickened, smooth, pointed. Seta l’ of femur smooth, bluntended. Leg II (Fig. 14 C). Tarsus with large padded claws and well developed flipper-like empodium. Solenidion ω 8 (7–8) finger-shaped, solenidion φ 4 (3–4) weakly clavate. Setae l’ and v” of femur short, needle-like. Seta pl” spine-like, smooth, u’ blunt-ended and barbed in distal half. Leg III (Fig. 15 A). Claws of same shape as on tarsus II. Solenidion φ 4 (3–4) weakly clavate. Setae pl” spine-like, smooth, u’ blunt-ended and barbed in distal half. Leg IV (Fig. 15 B). Setae d of femur, d and tc’ of tibiotarsus blunt-ended. Tibiotarsus about as long as its width. Seta tc’ much longer than other setae of tibiotarsus.

MALE and LARVA unknown.

Type material. Female holotype (slide VS 030814) and 14 female paratypes, RUSSIA, Tyumen Province, Kazanskiy District, vicinity of settlement Kazanskoye, 55° 37' 21.1"N, 69° 22' 17.7"E, in nest of Lasius flavus, 3 August 2014, coll. V.A. Stolbov; 4 female paratypes, RUSSIA, Tyumen Province, Tyumen District, vicinity of Tyumen, 57°09'50.4"N, 65°27'26.7"E, on Lasius flavus, 21 September 2014, coll. A.A. Khaustov; 2 female paratypes, same place, 26 July 2014, on Lasius flavus, coll. A.A. Khaustov.

Type deposition. Holotype and 18 paratypes deposited in TUMZ; 2 paratypes in ZISP.

Etymology. The name of a new species is referring to its distribution in Siberia.

Differential diagnosis. The new species belongs to the tackei species-group, which is characterized by reduction of setae e and h 2.Females of a new species are most similar to S. suavis Khaustov, 2008 by the absence of secondary sclerotized line on the poststernal plate. They differ from S. suavis by subequal, smooth, needle-like setae f and h 1 (vs. setae h 1 distinctly longer than f and both sparsely barbed in S. suavis) and by location of setae 4 a clearly anteriad to level of setae 4 b (vs. 4 a clearly posteriad to level of setae 4 b).