Paralycus subiasi Oshima & Shimano, 2024

Paralycus subiasi Oshima & Shimano sp. nov.

[Japanese name: Koke-oboro-dani]

( Figures 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 )

Materials Examined. Holotype: adult female, Japan, Torigajo-catsle, Yamanouchi , Touon City, Ehime Prefecture, 28-VI-2004, coll. M. Shiba from the moss on the bark of L yonia ovalifolia var. elliptica (Siebold & Zucc.) Hand. - Mazz. Type deposition. Holotype was deposited in the Collection of Arachnida, Department of Zoology, National Museum of Nature and Science, Tokyo ( NSMT) [collection number: NSMT-Ac 14773 ].

Diagnosis. Female Rostral seta long, reaching half the length of chelicera. Bases of lamellar setae slightly adjacent. Cheliceral seta cha shorter than half length of chelicera. Gastronotal setae d 1 and e 1 not reaching bases of next row of setae; c 2 reaching base of c p seta; f 1 and h 1 reaching bases of next row of setae. Epimeral seta 2a relatively short, not exceeding base of 1a. Epimeral seta 4a absent. Four pairs of genital setae present; distance g 3 – g 4 <g 1 – g 2 <g 2 – g 3. Leg trochanteral formula 0-0-0-0. Four setae on genu I; d, (l) and v′, genu II with two setae (l). Solenidion ω of tarsus I not expanding in middle; solenidion φ of tibia III short.

Description. Female Measurements. Idiosomal length 199, width 66.

Integument. Colorless, elongate and weakly sclerotized. Prodorsal shield, legs and coxae smooth. Dorsal side (except segment H and P), ventral side, chelicerae (basal part), and ovipositor finely striated.

Gnathosoma . Subcapitulum (28 × 24) with three pairs of filiform, smooth setae (a 11; m 12; h 9) and two pairs of filiform and smooth adoral setae (2, 4). Palp (22) simple, with four free segments; femur and genu separated by incomplete suture. Palpal setae formula: 0-1-0-1-9+ ω, including four eupathidia (sul, acm, ul; sul, acm, ul′ with expanded tips); inf absent. Postpalpal seta (ep 2) blunt. Chelicera (22) with two filiform and smooth setae (cha 4; chb 7); cha shorter than half of cheliceral length. Pharyngeal cupola long, reaching level of bs.

Prodorsum. Mid-dorsal region covered with shield-shaped plate, bearing two pairs of filiform and smooth setae (ro 14; le 21); ro reaching half the length of chelicera. Bases of setae le slightly adjacent. In dorsolateral region, three pairs of filiform setae (in, exa, exp) and one pair of clavate bothridial setae (bs) present; in (32), exa (13), exp (3) and bs (15 × 7) smooth.

Notogaster. Three transverse scissures divide notogaster into four regions; tf 1 and tf 2 faint while tf 3 conspicuous. Sixteen pairs of notogastral setae present. Four pairs of setae in region of segment C: c 1 (10), c 2 (16), c 3 (18) and c p (26). Four pairs of setae in region of segment DE: d 1 (14), d 2 (17), e 1 (22) and e 2 (23). Two pairs of setae in region of segment F: f 1 (35) and f 2 (30). Segments H and P fused with six pairs of setae: h 1 (30), h 2 (30), h 3 (21), p 1 (21), p 2 (25) and p 3 (10). All gastronotal setae filiform and smooth, not expanded at their bases. Seta c 2 reaching base of c p; d 1 not reaching base of e 1; e 1 not reaching base of f 1; f 1 reaching base of h 1; h 1 reaching base of p 1. Seta p 2 longer than p 1. Notogastral cupules absent.

Epimeral and podosomal regions. Epimeral setation 3-2-3-2; 1а (7), 1b (10), 1с (7), 2a (13), 2b (12), 3a (4), 3b (11), 3c (6), 4b (8) and 4c (3) filiform and smooth. Seta 2a not reaching base of 1a. Bases of 3a close to each other. One pair of triangular supracoxal setae (el 2) with rounded tips.

Anogenital region. Four pairs of genital setae: g 1 (7), g 2 (4), g 3 (9) and g 4 (8). Distance g 3 – g 4 <g 1 – g 2 <g 2 – g 3. Two pairs of minutes eugenital setae (3) and two pairs of genital papillae within genital orifice. Three pairs of adanal setae: ad 1 (14), ad 2 (33), ad 3 (7) and two pairs of anal setae: an 1 (7), an 2 (6). All anogenital setae filiform and smooth. Aggenital setae absent. Genital, anal and adanal plates absent. Genital tracheae reduced and represented by short cavities.

Legs. Relatively short. Measurements (total length from trochanter to tarsus, pretarsus excluded): I 46, II 36, III 36, and IV 38. Leg structure simple with highly visible five segments. Famulus ε of tarsus I bacilliform, thin and expanded at end; other setae filiform and smooth. Solenidion ω of tarsus I 5 × 1 not expanding in middle; ω of tarsus II 3 × 1 small and not expanding in middle. Solenidion φ of tibia I elongated and attenuate; φ of tibia III short (1) and bacilliform. Formula of leg setation (from trochanter to tarsus, solenidia in brackets): I 0-2-4-2(1)-9(1); II 0-2-2-3-6(1); III 0-2-0-2(1)-5; IV 0-2-0-2-5. Claws absent on all tarsi, each tarsus with minute empodial remnant and caruncle-like membrane.

Male Unknown.

Immatures Unknown.

Etymology. This species is named in honor of our esteemed colleague, Prof. Dr. Luis S. Subías, who made a great contribution to the knowledge of the diversity of oribatid mite species in the world.

Remarks. Paralycus subiasi sp. nov. is most similar to P. shibai Oshima & Shimano, 2024 in having four pairs of genital setae and the absence of epimeral seta 4a. However, P. subiasi sp. nov. differs from P. shibai in the following characteristics: gastronotal setae c 2 and f 1 longer, reaching the bases of the c p and h 1 setae, respectively (c 1 and f 1 not reaching the bases of the c p and h 1 setae, respectively, in P. shibai ); epimeral seta 2a shorter, not reaching the tip of 1a (exceeding the tip of 1a in P. shibai ); genual seta d on leg II absent (present in P. shibai ); trochanteral setae v′ on leg III absent (present in P. shibai ). Paralycus pyrigerus ( Berlese, 1905) which was described inadequately, also has long gastronotal setae f 1 and h 1, but P. subiasi sp. nov. has shorter setae e 1, which do not reach the base of f 1 (extending beyond the base of f 1 in P. pyrigerus ).

Additionally, for the labelling of epimeral setae, we do not follow the ontogenetic criterion (see the remark 15 in Norton & Franklin 2018), in fact we follow Kolesnikov et al. (2023). However, we need to correct a mistaken statement in our previous paper: only in Fig. 2B View FIGURE 2 of Oshima et al. (2024), the “ 4b ” and “ 4c ” should be changed to “ 4c ” and “ 4b ”, respectively.