Cosmolaelaps hallasanensis Oh, Joharchi, Lee & Jung, 2025, sp. nov.
Creators: name: Oh, Jaeseok
name: Joharchi, Omid
name: Lee, Seunghwan
name: Jung, Chuleui
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Mesostigmata
Laelapidae
Cosmolaelaps
Cosmolaelaps hallasanensis

description: Cosmolaelaps hallasanensis sp. nov.
(Figures 25–52)
Specimens examined. Holotype. female, Dosun-dong, Seogwipo-si, Hallasan, Jeju-do, Republic of Korea, 33°20'58.51"N 126°30'01.11"E, alt. 1350 m, 13 April 2019, C. Jung and J. Oh coll., soil in the tree cavity, NIBRIV0000862920. Paratypes. 26 females, 10 males and four deutonymph, San 98, Gyorae-ri, Jocheon-eup, Jejusi, Republic of Korea, 19 July 2021, J. Oh coll., in the nest of Aphaenogaster sp. (Hymenoptera: Formicidae) and one male, same data as holotype.
Diagnosis (adult) Dorsal shield reticulate, with 40 pairs of spatulate-mucronate setae (except j1 and z1), including three pairs of Zx setae and six unpaired Jx setae; presternal area poorly sclerotised, sternal shield with lineate-reticulate ornamentation on lateral surface, distinctly punctate centrally, ratio of shield length/width (at broadest level) ≃ 0.48; genital shield flask-shaped, widened posteriorly behind setae st5, surface reticulated with irregular, mostly longitudinal lines in anterior region, posteriorly with irregular polygonal pattern, basally composed of large cells, shield ratio of length/width (at broadest level) ≃ 1.6, anal shield slightly longer than wide, with ratio of length/width (at broadest level) ≃ 1.18, post-anal seta thickened; opisthogastric setae spatulate, except Jv1–Jv3, Zv1, and Zv2; fixed digit of chelicera with 10–12 teeth of various sizes. Most setae on legs spatulate. In male, holoventral shield bearing 10 pairs of setae. Femur II in both female and male with strong spur-like seta on the ventral side (av).
Description (adult female)
(Figures 25–42)
Six specimens were measured.
Dorsal idiosoma (Figures 25, 26 & 31). Dorsal shield oval-shaped, 737–790 long, 523–538 wide, covering entire idiosoma dorsally; shield with distinct reticulation, bearing 40 pairs of almost uniform spatulate-mucronate setae (with a discernable basal asymmetric protuberance): 22 pairs of podonotal setae and 18 pairs of opisthonotal setae, including three pairs of Zx setae between J and Z setae and six unpaired supernumerary seta Jx between J1 and J5, dorsal setae mostly homogeneous in length and thickness, barely reaching base of next posterior setae (58–69), except j1 (48–51) cunate-tricarinate and z1 acuminate (36–39) (Figures 25, 26 & 31). Shield with 23 pairs of discernible pore-like structures, including 16 poroids and seven gland openings (gd1, gd2, gd4–6, and gd8–9).
Ventral idiosoma (Figures 27 & 32–35). Tritosternum with paired pilose laciniae (119–135), columnar base 48– 60 long × 16–22 wide; presternal area poorly sclerotised, sternal shield length 93–112, narrowest between coxae II (123–135), widest between coxae II and III (218–230), with reticulate ornamentation throughout, except central and posterior parts distinctly punctate (Figures 27 & 33), anterior margin of shield conspicuous, posterior margin slightly concave, anterolateral corners narrowly extending between coxae I–II, distally bearing gland pores gvb; endopodal elements between coxae II and III fused with shield, endopodal elements III/IV elongate, narrow and curved, shield bearing three pairs of smooth long setae (st1 70–80, st2 68–75, st3 66–76), extending beyond of next posterior setae, and two pairs of sub-oval poroids (iv1 and iv2, mesal to setae st1 and between st2 and st3, respectively). Metasternal setae st4 (55–61) and metasternal poroids located on soft integument. Genital shield flask-shaped, slightly expanded laterally behind setae st5 (Figures 27 & 34), length 259–280, maximum width 169–173, posterior margin rounded, anterior margin of shield convex, overlapping posterior area of sternal shield, reaching base of setae st3, surface reticulated with irregular, mostly longitudinal lines in anterior region, posteriorly with irregular polygonal pattern, basally composed of large cells, bearing a pair of simple setae st5 (58–67) inserted on lateral margins of shield, near level of posterior edge of coxae IV; paragenital poroids iv5 located on soft cuticle lateral to shield near seta st5. Anal shield pear-shaped, rounded anteriorly, length 124–142, width 110–120, anterior half lineate-reticulate, para-anal setae and post-anal seta subequal in length (31–36), post-anal seta thickened, cribrum consisting of a terminal tuft with some irregular rows of spicules and a pair of anterior arms extending slightly beyond post-anal seta; anal gland pores (gv3) on anterolateral margin of anal shield (Figures 27 & 35). Soft opisthogastric cuticle surrounding genital and anal shields with one pair of elongated metapodal plates (23–33 long × 3–5 wide), six pairs of poroids (five ivo; ivp) and 17 pairs of spatulate setae (32–38) (Jv1–Jv5, Zv1– Zv5, R1–R5, and UR2–UR3), except Jv1–Jv3 and Zv1–Zv2 setiform and slightly longer (46–55) (Figures 27 & 32). Two exopodal platelets present between coxae II–III and III–IV, exopodal platelets between coxae II–III small, subtriangular, those behind coxae III–IV and parapodal platelets fused, surrounding coxa IV and bearing gland pore gv2 (Figures 27 & 32). Peritrematal shield well developed laterad peritremes, bearing one gland pore and one poroid at level near coxae II–III, post-stigmatic extension of shield relatively wide, with two pairs of poroids and one pair of gland pores; anterior region of peritrematal shield fused to anterior margin of dorsal shield behind setae z1. Peritremes long, extending to mid-level of coxa I (near s1) (Figures 27 & 32).
Gnathosoma (Figures 28–30 & 36–38). Anterior margin of epistome convex, irregularly denticulate (Figure 29). Hypostomal groove greatly widened, with six transverse rows of denticles, each row with 10–35 tiny denticles, with smooth anterior and posterior transverse lines, groove wider anteriorly, progressively narrowing from anterior to posterior (Figure 28 & 36). Hypostome with four pairs of smooth setae, h3 (85–93)> h1 (67–73)> pc (65–70)> h2 (30–35) (Figure 28 & 36). Corniculi robust and horn-like, internal malae longer than corniculi, comprising a pair of pilose median projections, and 10–12 lateral, longer, tentacle-like, smooth projections; labrum with pilose surface (Figure 28 & 36); supralabral process not distinct. Chaetotaxy of palps: trochanter 2, femur 5, genu 6, tibia 14, tarsus 15, all setae smooth; palpfemur with seta al paddle-like; palpgenu with al1 and al2 stout, blunt, thickened and spatulate; palptarsal apotele two-tined (Figure 38). Fixed digit of chelicera with an offset distal tooth (gabelzhan), followed by 10–12 various sized teeth (mostly small), a setaceous pilus dentilis, dorsal cheliceral seta small and prostrate, arthrodial membrane with a rounded flap and normal filaments; cheliceral dorsal and lateral lyrifissures distinct; movable digit with two mid-sized teeth (Figures 30 & 37).
Insemination structures. Not seen, apparently unsclerotised.
Legs (Figures 39–42). Legs II and III short (551–619, 539–584), I and IV longer (675–787, 706–828). Chaetotaxy normal for free-living Laelapidae: Leg I (Figure 39): coxa 0-0/1, 0/1-0, trochanter 1-1/2, 0/1-1 (pl spatulate), femur 2-2/1, 3/3-2 (posterior dorsal and ventral setae spatulate, except pv3), genu 2-3/2, 3/1-2 (all setae spatulate, except ventral and al2), tibia 2-3/2, 3/1-2 (all setae spatulate, except ventral and anterior laterals). Leg II (Figure 40): coxa 0-0/1, 0/1-0, trochanter 1-1/1, 0/1-1, femur 2-3/1, 2/2-1 (ad1, pd1, pd2, pl spatulate and av spur-like), genu 2-3/1, 2/1-2 (all setae spatulate, except ventral and anterior laterals, ventral setae thickened), tibia 2-2/1, 2/1-2 (all setae spatulate, except ventral and anterior laterals, ventral setae thickened). Leg III (Figure 41): coxa 0-0/1, 0/1-0, trochanter 1-1/1, 0/1-1 (ad spatulate), femur 1-2/1, 1/0-1 (ad1 spatulate), genu 2-2/1, 2/1-1 (all setae spatulate, except ventrals), tibia: 2-1/1, 2/1-1 (all setae spatulate, except ventrals). Leg IV (Figure 42): coxa 0-0/1, 0/0-0, trochanter 1-1/1, 0/1-1 (ad spatulate), femur 1-2/1, 1/0-1 (ad1, ad2, al, and av spatulate), genu 2-2/1, 3/0-1 (all setae spatulate, except av and pl), tibia 2-1/1, 3/1-2 (all setae spatulate, except ventrals). Tarsi II–IV with 18 setae (3-3/2, 3/2-3 + mv, md); with some ventral and lateral setae thickened and spatulate, see Figure 40–42. All pretarsi with well-developed paired claws, rounded pulvilli and normal ambulacral stalk.
Description (adult male)
(Figures 43–46)
six specimens were measured.
Dorsal idiosoma. Dorsal shield 567–622 long, 420–478 wide; ornamentation and chaetotaxy as in female.
Ventral idiosoma (Figures 43 & 45). Sternal, genital, endopodal, ventral and anal shields fused into holoventral shield, 475–491 long from anterior to posterior margins of shield, 190–195 wide at level of st2, 173–179 at st3 level and 261–273 at broadest point, posteriorly to coxae IV; shield reticulate throughout (ornamentation only partly drawn on Figures 43 & 45), with five pairs of simple sternal setae (st1–st5), and five pairs of smooth ventral setae (Jv1–Jv3, Zv1, and Zv2), plus three smooth circum-anal setae, para-anal setae and post-anal seta subequal in length, post-anal seta thickened, with five pairs of poroids; gland pore gv2 behind coxa IV not discerned; cribrum with 3–4 irregular rows of spicules; metapodal platelets narrow and partly fused to holoventral shield (Figures 43 & 45). Soft opisthogastric and lateral cuticle with 13 pairs of spatulate setae, except Jv4. Peritremes, peritrematal shields and other ventral structures similar to those in female.
Gnathosoma (Figure 44). Fixed digit of chelicera with 11–13 teeth of various sizes in addition to apical hook, pilus dentilis setaceous, slightly thicker than in female. Movable digit of chelicera with a relatively large tooth, spermatodactyl digitiform, gently curved, with rounded tip, free portion of spermatodactyl shorter than movable digit (53–60). Other gnathosomal structures similar to those in female.
Legs (Figure 46). Chaetotaxy as in female, including strong spur-like seta (av) on the ventral side of femur II.
Description (deutonymph)
(Figures 47–52)
Four specimens were measured.
Dorsal idiosoma (Figure 47). Dorsal shield entire 737–790 long, 523–538 wide, not covering entire dorsal idiosoma, with a narrow incision in each lateral margin, just anteriorly to S1 and extending medially about up to level of z6, bearing 40 pairs of almost uniform spatulate-mucronate setae: 22 pairs of podonotal setae and 18 pairs of opisthonotal setae, including three pairs of Zx setae between J and Z setae and six unpaired supernumerary seta Jx between J1 and J5, dorsal setae mostly homogeneous in length and thickness, barely reaching base of next posterior setae (35–40), except j1 cunate-tricarinate and z1 acuminate. Pore-like structures essentially as in adult female.
Ventral idiosoma (Figure 48). Tritosternum with paired pilose laciniae (84–105), trapezoidal base 43–49 × 11–15 wide. Sternal shield length 255–265 and widest 111–120, finely reticulate throughout, with four pairs of relatively long setae (st1–st4) (27–65) and three pairs of poroids. Genital setae st5 (30–36) and paragenital poroids on soft cuticle at level of posterior margin of shield; endopodal shields between coxae II–III and coxae III–IV absent. Anal shield subtriangular (103–110 long, 84–94 wide), anterior half lineate-reticulate, para-anal setae and post-anal seta subequal in length (21–29), cribrum small, gland pores gv3 on lateral margins of shield. Soft opisthogastric cuticle as in adult female. Peritrematal shields anteriorly free, not fused with dorsal shield, bearing one gland pore and one poroid at level near coxae II–III; post-stigmatic extension of shield not developed, two pairs of related poroids on small platelets.
Gnathosoma. similar to adults.
Legs (Figures 49–52). Legs II (Figure 50) (443–500) and III (Figure 51), (433–461) short, I (Figure 49) (591– 650) and IV (Figure 52) (590–620) longer. Pretarsi, claws, and chaetotaxy of legs I–IV as in adult female.
Etymology. The specific name is derived from the name of the region (Hallasan Mountain, Jeju, Korea) in which the type locality occurs.
Differential diagnosis. Dorsal shield usually bearing 39 pairs of setae (22 pairs on podonotal and 17 pairs on opisthonotal regions including two pairs of Zx setae between J and Z series of each side, as well as 1–5 unpaired setae (Jx) between J series as in most Cosmolaelaps species; but opisthonotal region of dorsal shield with 1– 3 extra pairs of setae in some species: C. anserina (Karg, 1981); C. brevipedestra (Karg, 1985); C. carvalhoi (Aswegen and Loots, 1970); C. communis Trägårdh, 1931; C. crossocauda (Karg, 2006); C. cursoria (Karg, 1988); C. euarmata (Karg, 1996); C. euventricosa (Karg, 1995); C. keni (Hafez et al., 1982); C. leptolingua (Karg, 1994); C. lingua (Karg, 1987); C. longodigiti (Karg, 1979); C. mahuncai (Karg, 1988); C. paracuneifer (Gu & Bai, 1992); C. penicillata (Karg, 1979); C. reticulatus (Xu & Liang, 1996); C. robustochaetes (Ma & Lin, 2009), and C. trifidus (Pearse et al., 1936). However, C. hallasanensis post-anal can be easily distinguished from all those species by the following combination of characters: (1) dorsal shield bearing 40 pairs of spatulate-mucronate setae, including three pairs of Zx setae and six unpaired supernumerary seta (Jx), (2) sternal shield bearing three pairs of long setae, extending beyond of next posterior setae, (3) genital shield flask-shaped, widened posteriorly behind setae st5, (4) hypostomal groove greatly widened, with six transverse rows of denticles, each row with 10–35 tiny denticles, (5) fixed digit of chelicera with 10–12 teeth of various sizes, (6) femur II in both female and male with strong spur-like seta on the ventral side (av), (7) Most of setae on legs spatulate. Cosmolaelaps paracuneifer (Gu & Bai, 1992) and C. claviger (Berlese, 1883) share a general resemblance to C. hallasanensis. However, there are notable distinctions between the three species. C. claviger (Berlese, 1883) possesses 39 pairs of spatulate dorsal setae inserted on small tubercles, whereas C. hallasanensis has 40 pairs of spatulate-mucronate setae. Additionally, C. hallasanensis differs from C. paracuneifer (Gu & Bai, 1992) in the shape of its dorsal setae.
description: Published as part of Oh, Jaeseok, Joharchi, Omid, Lee, Seunghwan & Jung, Chuleui, 2025, New species and new records of Cosmolaelaps Berlese (Acari: Laelapidae) from the Republic of Korea, with a review of the Korean species of the genus, pp. 55-92 in Zootaxa 5569 (1) on pages 65-73, DOI: 10.11646/zootaxa.5569.1.2, http://zenodo.org/record/14703918