Amphialycus holarcticus Uusitalo, 2020

Amphialycus holarcticus Uusitalo, 2020

( Figs. 12A–E, 13A–D)

Amphialycus (Amphialycus) holarcticus Uusitalo, 2020: 109 , figs. 1–10; holotype from Larix stand,

Tuva Republic, Russia.

Description. Dorsum (n= 1 female, Figs. 12A, B). Length 560–700 µm; ciliate setae with longer central points on caudal segments. Prodorsum with: naso prominent, cone-shaped, longitudinally striated; pilose setae vi, sce and exp on hard integument, exp smallest and anterior to eyes, setae in pubescent; two pairs of filamentous sensilla ve and sci ciliated along entire length; both pairs of lateral eyes finely striated.

Venter ( Figs. 12D, E). Setae shorter and less ciliated than dorsal setae; genital setae of various lengths, mostly elongated closer to mesial margin, 35–45 per valve; anal setae 5–9 per valve, caudal setae longest.

Gnathosoma ( Fig. 12C). Two pairs of cheliceral setae, anterior pair abaxial and smooth, posterior pair forked, in more dorsal position; rutella widen to a round hyaline membrane with two lobes apically; three pairs of well-developed adoral setae; four microtrichous eupathidia on palps close to each other but clearly apart.

Legs ( Figs. 13A–D). Pedal setae elongated; solenidial formula for tarsi, tibiae, genua and femora on legs I-II- III-IV, respectively: 2-1-0-0, 3-2-2-0, 3-2-2-1, 2-0-0-1+0, tarsi I and II with spine-like abaxial famulus.

Material examined. Holotype female from Larix stand, 100 m away from the river, on north slope, litter and soil of Larix , Rhododendron , Spiraea , Clematis , Caragana and Pleurozium , southern range of Tannu-Ola, 1350 m.a.s.l., 50°54’N 94°29’E, Aryskanny-Khem River, 5 km ENE of Khol-Oozha Village, Tuva Republic, Russia, 18 July 1995, Matti Uusitalo, from sample MU 95-39. Deposited on SEM-stub U200 at the Zoological Museum, University of Turku, Finland.

15 specimens from Utah Juniper ( Juniperus osteosperma ) duff, Blacksmith Fork Canyon, Cache Co. Utah, USA , 24 April 1970, G.F. Knowlton & W.J. Hanson; of them, 10 females and 4 males deposited at the Acarology Laboratory , Ohio State University, coll. no. AL0726 ; one female at the Zoological Museum , University of Turku, Finland .

Differential diagnosis. This species can be segregated from other Amphialycus species by having a broad naso with longitudinally arranged striae and tapering end, three pairs of adoral setae, two pairs of cheliceral setae (posterior being forked), and a great number of genital setae.

Remarks. A. holarcticus was coded as ‘amp’ in Uusitalo (2010, fig. 1). The anterior pair of eyes is extremely finely striated (see Uusitalo 2020: SEM fig. 1, by high magnification) which is typical to the genus Amphialycus , but overlooked by Uusitalo (2010, 2020, mentioned as glabrous in text).