Alycus utahensis, Uusitalo, 2025

Alycus utahensis sp. nov.

( Figs. 3A–E, 4A–E)

Description. Dorsum (n= 1 female, Figs. 3A, B). Length 570 µm; parallel ridges on soft integument meandering, mostly continuous; strong neotrichy, ciliate dorsal setae with a long central point and 5–7 easily distinguishable cilia, caudal setae longest with long cilia resembling prodorsal setae in; on prodorsum: thin strip of hard integument connecting the eye area, setae exp above reduced (lensless) pair of posterior eye areas and main body of prodorsal sclerite, narrow strip of hard integument continuous from proboscis-like naso up to sensillar area and covered by longitudinal lamellae of various size classes, setae vi and sce on separate microplates, setae in longest. (One extra seta inserted proximal to the right seta vi, arrow).

Venter ( Figs. 3D, E, 4A). Genital setae 29–31 per valve; one pair of eugenital setae (broken lines, arrows); anal setae 7 per valve; 7 setae on coxa IV.

Gnathosoma ( Fig. 3C). Rutella with broad shaft, three ventrodistal projections, and an apical point; three pairs of adoral setae on subcapitulum; one pair of dorsal cheliceral setae. Three pairs of pseudacanthoid palpal eupathidia apically.

Legs ( Figs. 4B–E). Solenidial formula for tarsi, tibiae, genua and femora of legs I, II, III and IV, respectively: 2-1-0-0, 1-2-2-0, 4-2-2-1, 2-0-0-0, tarsi I and II with laterodistal peg-like famulus.

Type material. Holotype female from Abies duff, Hayden Fork (High Uintah Mtn), Summit Co., Utah, USA, 26 August 1970, G.F. Knowlton & W.J. Hanson: holotype on slide NA1, collection number AL0709. Deposited at the Acarology Laboratory, Ohio State University. The specimen is dorsal side up, sealed in Glyptal and under 20 mm round cover glass.

Differential diagnosis. Superficially the large (570 µm in length) American species Alycus utahensis sp. nov. resembles the generally smaller European Alycus roseus Koch (vs. 350–560 µm), redescribed by Uusitalo (2010: 40–45, figs. 8–24), but there are qualitative and quantitative differences which justify its status of a new species. The most obvious differences are as follows: (1) neotrichy on dorsal side is ca. 30 % stronger ( Figs. 3B vs. 1B and van der Hammen, 1989: fig. 48); (2) the ciliated setae with elongated shafts on segments H, PS and AD have two cilia forked at the tip of the shaft and as long as the shaft ( Fig. 3B) vs. cilia on caudal setae of A. roseus are shorter than the shaft which is long or terminates in a single cilium in Fig. 1B; (3) the numbers of genital setae ( Fig. 3D) and setae on coxal field IV ( Fig. 4A) are 29–31 and 5–7, respectively (vs. 18–24 and 1–2 in Figs. 1D, 2A, and in Europe acc. Grandjean, 1937: 60; van der Hammen, 1989: fig. 47); (4) the ridges on dorsal integument are more continuous ( Fig. 3A, D) vs. fragmentary ( Fig. 1A and Uusitalo 2010: figs. 8–10); (5) length of the prodorsal setae in is 40 µm ( Fig. 3A) vs. ca. 20–25 µm for A. roseus ( Fig. 1A and Uusitalo 2010: fig 8); and (6) there is no solenidion on femur IV while A. roseus has one ( Figs. 4E vs. 2E and Uusitalo 2010: fig. 11).

Remarks. Alycus roseus C. L. Koch, 1842 , Pachygnathus nr. dugesi or undescribed species of Alycus have been reported from Oregon, New Mexico, Wyoming, Florida, Illinois, Louisiana, Nebraska, and Wisconsin by Kamill et al. (1985), Walter (1987, 1988) and Kethley (1990 b, 1991).Also unconfirmed are records of Alycus roseus from native grasslands in central USA ( Walter 1987). The solitary female from Abies duff in Utah with one extra prodorsal seta ( Fig. 3A, B, arrow) is unusual but may be anomaly of this single specimen or perhaps an expression of increased neotrichy. However, the character state combination listed above for Alycus utahensis strongly suggest that the specimen represents a new species.

Etymology. The specific name refers to the state Utah, the state of the type locality.