Cosmolaelaps cavosternalis, Oh & Joharchi & Lee & Jung, 2025

Cosmolaelaps cavosternalis sp. nov.

( Figures 1–24 View FIGURES 1–5 View FIGURES 6–12 View FIGURES 13–16 View FIGURES 17–18 View FIGURES 19–24 )

Specimens examined. Holotype. Female , 350-1, Odaesan-ro, Jinbu-myeon, Pyeongchang-gun, GW, Republic of Korea, 13 October 2021, J. Oh coll., nest of ant . Paratypes. 38 females, nine males, and two deutonymphs, same data as holotype .

Diagnosis (adult). Dorsal shield covered with serrated patch-like reticulation throughout, with 40 pairs of cuneiform setae (serrated apical margin, with discernable asymmetric basal protuberance, except S2), with 8–12 unpaired Jx setae; sternal shield covered with same reticulation as in dorsum, anterior margin of sternal shield deeply concave, sternal setae elongate, st1 off the shield, ratio of sternal shield length/width (at broadest level) ≃ 0.62; genital shield flask-shaped, strongly expanded behind coxa IV, surface of shield with irregular polygonal reticulation, shield ratio of length/width (at broadest level) ≃ 1.3, anal shield slightly longer than wide, with ratio of length/width (at broadest level) ≃ 0.97; ophisthogastric setae spatulate, except Jv1–Jv3, Zv1, and Zv2; fixed digit of chelicera with 9–10 teeth of various sizes. Most of setae on legs thick and spatulate. In male, holoventral shield bearing nine pairs of setae.

Description (adult female)

( Figures 1–16 View FIGURES 1–5 View FIGURES 6–12 View FIGURES 13–16 )

Five specimens were measured.

Dorsal idiosoma ( Figures 1 View FIGURES 1–5 , 6 View FIGURES 6–12 ). Dorsal shield oval-shaped, 800–920 long, 610–673 wide, covering entire idiosoma dorsally; shield with distinct serrated tiny spine-like marking, bearing 40 pairs of spatulate setae (serrated apical margin, with discernable asymmetric basal protuberance), except j1, z1 serrated but without asymmetric basal protuberance: 22 pairs of podonotal setae, 18 pairs of opisthonotal setae including three pairs of Zx setae, and 8–12 unpaired supernumerary setae Jx between J1 and J5, dorsal setae mostly homogeneous in length, never reaching base of next posterior setae (41–61). Shield with 11 pairs of discernible pore-like structures, including six poroids (id2, id4, id6, idm2, idl1 and idx) and five gland opening (gd1, gd2, gd5, gd6, and gd8).

Ventral idiosoma ( Figures 2 View FIGURES 1–5 , 7 & 8 View FIGURES 6–12 ). Tritosternum with paired pilose laciniae (112–143), columnar base 47–58 long × 12–17 wide; presternal area without sclerotised plates, bearing st1 and iv1 ( Figures 2 View FIGURES 1–5 & 8 View FIGURES 6–12 ). Sternal shield 100–144 long, narrowest between coxae II (136–143), widest at level of endopodal between coxae II and III (207– 232), completely reticulate, consisting of rows of tiny spine-like markings ( Figures 2 View FIGURES 1–5 , 7 & 8 View FIGURES 6–12 ), anterior margin of shield strongly concave, conspicuous, anterolateral corners narrowly extending between coxae I–II, posterior margin slightly concave. Shield bearing two pairs of long smooth setae (st1 73–75, st2 63–77, st3 56–69), not extending beyond next posterior setae, and a pair of thin rectangular poroids (iv2, between st2 and st3, respectively), metasternal setae st4 (47–63) and metasternal poroids (iv3) located on soft integument ( Figure 8 View FIGURES 6–12 ); endopodal elements between coxae II–III fused with shield, endopodal elements III–IV elongate, narrow, and curved. Genital shield flask-shaped, distinctly expanded laterally behind st5, length 288–320, maximum width 217–258, posterior margin rounded, anterior margin of shield slightly convex, abutting posterior margin of sternal shield, surface reticulated with irregular, polygonal pattern, bearing a pair of simple st5 (50–65) inserted on lateral margin of shield, near level of posterior edge of coxae IV. Paragenital poroids iv5 located on soft cuticle lateral to shield near setae st5; anal shield pear-shaped, rounded anteriorly, 135–155 long, 138–166 wide, anterior half covered with lineate reticulation, para-anal setae and post-anal seta simple and subequal in length (21–31), cribrum consisting of a terminal tuft with some irregular rows of spicules and a pair of anterior arms extending at level of between anal orifice and post-anal seta. Anal gland pores (gv3) on lateral margin of shield; soft opisthogastric cuticle surrounding genital, anal shields, and a pair of elongated metapodal plates (36–61 long × 9–19 wide), two pairs of poroids (iv5, ivo) and 13 pairs of spatulate setae (13–44) (Jv4, Jv5, Zv3–Zv5, R1–R5), except Jv1–Jv3, Zv1, and Zv2 setiform (20–33). 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).

Gnathosoma ( Figures 3–5 View FIGURES 1–5 & 9–12 View FIGURES 6–12 ). Anterior margin of epistome slightly convex, irregularly denticulate ( Figures 4 View FIGURES 1–5 & 11 View FIGURES 6–12 ); Hypostomal groove considerably widened, with six transverse rows of denticles, each row with 12–40 tiny denticles, groove wider anteriorly, progressively narrowing from anterior to posterior ( Figures 3 View FIGURES 1–5 & 9 View FIGURES 6–12 ). Hypostome with four pairs of smooth setae, h3 (85–104)> h1 (67–89)> pc (57–65)> h2 (36–41) ( Figures 3 View FIGURES 1–5 & 9 View FIGURES 6–12 ). Corniculi robust and horn-like, internal malae longer than corniculi, comprising a pair of pilose median projections, and 22–26 lateral, longer, tentacle-like, smooth projections; labrum with pilose median surface, supralabral process indistinct; chaetotaxy of palps: trochanter 2, femur 5, genu 6, tibia 14, tarsus 15, all setae smooth, palpfemur with seta al thickened and blunt; palpgenu with al1 and al2 stout, blunt, and thickened. Palptarsal apotele two-tined ( Figure 10 View FIGURES 6–12 ); fixed digit of chelicera with an offset distal tooth (gabelzhan), followed by 9–10 various sized teeth, a setaceous pilus dentilis, dorsal cheliceral seta small and prostrate, arthrodial membrane with a rounded flap and normal filaments, dorsal and lateral lyrifissures distinct, movable digit bidentate ( Figures 5 View FIGURES 1–5 & 11 View FIGURES 6–12 ).

Insemination structures. Not seen, apparently unsclerotised.

Legs ( Figures 13–16 View FIGURES 13–16 ). Leg II (604–681) and III (600–680) short, I (721–808) and IV (826–933) longer. Chaetotaxy normal for free-living Laelapidae plus pl setae on genu III and tibia III: Leg I ( Figure 13 View FIGURES 13–16 ): coxa 0-0/1, 0/1-0, trochanter 1-1/2, 0/1-1 (al spatulate), femur 2-2/1, 3/3-2 (al1, ad1, and pd1–pd3 spatulate), genu 2-3/2, 3/1-2 (all setae spatulate, except ventral setae), tibia 2-3/2, 3/1-2 (all setae spatulate, except ventral setae). Leg II ( Figure 14 View FIGURES 13–16 ): coxa 0-0/1, 0/1-0, trochanter 1-1/1, 0/1-1, femur 2-3/1, 2/2-1 (ad1, pd1, pd2, and pl spatulate), genu 2-3/1, 2/1- 2 (ad1–ad3, pd1, pd2, pl1, and pl2 spatulate), tibia 2-2/1, 2/1-2 (pl1 and pl2 spatulate). Leg III ( Figure 15 View FIGURES 13–16 ): coxa 0-0/1, 0/1-0, trochanter 1-1/1, 0/1-1 (al spatulate), femur 1-2/1, 1/0-1 (ad1, ad2, and pd spatulate), genu 2-2/1, 2/1-2 (pd1, pd2, pl1, and pl2 spatulate), tibia: 2-1/1, 2/1-2 (ad, pd1, pd2, pl1, and pl2 spatulate). Leg IV ( Figure 16 View FIGURES 13–16 ): coxa 0-0/1, 0/0-0, trochanter 1-1/1, 0/1-1 (al spatulate), femur 1-2/1, 1/0-1 (ad1, ad2 spatulate), genu 2-2/1, 3/0-1 (ad1, ad2, pd1–pd3 spatulate), tibia 2-1/1, 3/1-2 (ad, pd1–pd3, and pl2 spatulate). Tarsi II–IV with 18 setae (3-3/2, 3/2-3 + mv, md); with some ventral and lateral setae thickened and spatulate, see Figures 14–16 View FIGURES 13–16 . All pretarsi with well-developed paired claws, rounded pulvilli and normal ambulacral stalk.

Description (adult male)

( Figures 17, 18 View FIGURES 17–18 )

Five specimens were measured.

Dorsal idiosoma. Dorsal shield 744–761 long, 561–590 wide; ornamentation and chaetotaxy as in female.

Ventral idiosoma ( Figure 17 View FIGURES 17–18 ). Sternal, genital, endopodal, ventral, and anal shields fused into holoventral shield, 545–548 long from anterior to posterior margins of shield, 137–148 wide at level of st2, 145–148 at level of st3 and 361–374 at broadest point, posteriorly to coxae IV; shield reticulate throughout (ornamentation only partly drawn on Figure 17 View FIGURES 17–18 ), with four pairs of simple sternal setae (st1–st5), and five pairs of smooth ventral setae (Jv1– Jv3, Zv1, Zv2), plus three smooth circum-anal setae, para-anal setae and post-anal seta subequal in length, with six pairs of poroids; cribrum with 3–4 irregular rows of spicules; metapodal platelets completely fused to holoventral shield. Soft ophisthogastric and lateral cuticle with 14–16 pairs of spatulate setae. Peritremes, peritrematal shields, and other ventral structures similar to those in female.

Gnathosoma ( Figure 18 View FIGURES 17–18 ). Fixed digit of chelicera with 9–10 teeth of various sizes in addition to apical hook.

Movable digit of chelicera monodentate, spermatodactyl digitform, gently curved, with rounded tip, free portion of spermatodactyl shorter than movable digit (38–49). Other gnathosomal and cheliceral structures similar to those in female.

Legs. Chaetotaxy as in female.

Description (deutonymph)

( Figures 19–24 View FIGURES 19–24 )

2 specimens were measured.

Dorsal idiosoma ( Figure 19 View FIGURES 19–24 ). Dorsal shield 660–691 long, 480–513 wide, not covering entire dorsal idiosoma, with a narrow incision in each lateral margin (incision extended from s6 to z6), bearing 40 pairs of almost uniform spatulate setae (similar as in adult): 22 pairs of podonotal setae and 18 pairs of opisthonotal setae, including three pairs of Zx setae between J and Z setae and 12 unpaired supernumerary seta Jx between J setae, dorsal setae mostly homogeneous in length and wide, never reaching base of next posterior setae (28–46), except j1, j2, z1, and Z5 without basal protuberance. Pore-like structures essentially as in adult female.

Ventral idiosoma ( Figure 20 View FIGURES 19–24 ). Tritosternum with paired pilose laciniae (100–123), trapezoidal base 54–57 long × 17–18 wide. Sternal shield 280–293 long and 126–135 wide, finely polygonal reticulate throughout, with four pairs of relatively long setae (st1–st4) (64–70; 49–57; 40–44; 27–35) and three pairs of poroids. Anterior margin of sternal shield inconspicuous, connected with presternal lineate reticulation. Genital setae st5 (36–41) and paragenital poroids on soft cuticle at level of posterior margin of shield; endopodal shields between coxae II–III and coxae III–IV incompletely fragmented. Anal shield subtriangular (119–130 long, 32–46 wide), lineate-reticulate throughout, para-anal setae and post-anal seta subequal in length (20–25), cribrum similar to adult, gland pores gv3 on lateral margins of shield. Soft opisthogastric cuticle as in adult female. Peritrematal shields anteriorly free, not fused with dorsal shield, without gland pore and poroid; post-stigmatic extension of shield not developed, two pairs of related poroids on small platelets.

Gnathosoma. similar to adults.

Legs ( Figures 21–24 View FIGURES 19–24 ). Legs II ( Figure 22 View FIGURES 19–24 ) (516–543) and III ( Figure 23 View FIGURES 19–24 ), (528–537) short, I ( Figure 21 View FIGURES 19–24 ) (665– 685) and IV ( Figure 24 View FIGURES 19–24 ) (656–686) longer. Pretarsi, claws, and chaetotaxy of legs I–IV as in adult female.

Etymology. The name of the new species “ cavosternalis ” is derived from the concave shape of the sternal shield.

Diffential diagnosis. This species is close to other cuneifer -group species. However, C. cuneifer ( Michael, 1891) : 39 pairs of dorsal setae + 14 accessory setae, dorsal setae r1 acicular-shaped, sternal shield without spine-like reticulation, genu IV with two pl setae ( Evans & Till, 1966). C. neocuneifer Evans & Till, 1966: 39 pairs of dorsal setae + nine accessory setae, post-anal seta spatulate, sternal shield without spine-like reticulation ( Evans & Till, 1966). C. paracuneifer Gu & Bai, 1992: 39 pairs of dorsal setae + six accessory setae, dorsal setae S1 acicular-shaped, sternal shield without spine-like reticulation, two pairs of metapodal plates ( Gu & Bai, 1992). C. bengalensis Bhattacharyya, 1968: 37 pairs of dorsal setae + four accessory setae (39 pairs of dorsal setae in original description), dorsal setae without basal protuberance, presternal platelet distinctly sclerotised, sternal shield with three pairs of barbed setae, post-anal seta spatulate ( Bhattacharyya, 1968). C. bicuspisetosa Willmann, 1953 : Shape of dorsal setae spatulate and bifurcated apically except for z1 ( Willmann, 1953). C. tuberculata Mašán, 1992: 39 pairs of dorsal setae + one or two accessory setae, sternal setae st1 on the shield, metapodal plates two pairs ( Mašán, 1992). C. aciphila Karg, 1987: 37 pairs of dorsal setae + five accessory setae, dorsal setae z1, s1, s3, s6, r2–r5, Z5, S1–S3, S5, and R1 acicular-shaped, dorsal setae without basal protuberance, sternal setae st1 on the shield ( Karg, 1987). C. ornata ( Berlese, 1903) : Dorsal setae broadened and spatulate but without apical denticles, with fine hair-like processes ( Hull, 1918; Mašán, 1992). C. sansungensis sp. nov.: 38 pairs of dorsal setae + four accessory seta, dorsal setae without basal protuberance, sternal setae st1 on the shield, genu IV with two pl setae.