Cosmolaelaps robustochaetes Ma & Lin, 2009

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, Zootaxa 5569 (1), pp. 55-92 : 78-82

Cosmolaelaps robustochaetes Ma & Lin, 2009

( Figures 68–85 )

Cosmolaelaps robustochaetes Ma & Lin, 2009: 29 .

Hypoaspis (Cosmolaelaps) robustochaetes .— Bai & Ma, 2012: 557; Bai et al., 2016: 9.

Cosmolaelaps robustochaetes .— Moreira et al., 2014: 320.

Specimens examined. 11 Females, eight males, San 39, Jeodong-ri , Ulleung-eup, Ulleung-gun, Ulleung-do, GB, Republic of Korea, 37°29'48"N 130°53'30"E, 29 September 2021, J. Oh coll., soil & leaf litter .

Diagnosis (adult). Dorsal shield covered with scale-like reticulation posteriorly,with 41 pairs of spatulate, curved scimitar shaped setae (except j1, z1, and Z5), including 10 unpaired Jx setae; presternal area palely sclerotised and eyebrow-shaped, sternal shield with lineate-reticulate ornamentation on lateral surface, distinctly punctate centrally, ratio of shield length/width (at broadest level) ≃ 0.68; genital shield flask-shaped strongly expanded behind coxa IV, surface of shield with irregular polygonal reticulation, shield ratio of length/width (at broadest level) ≃ 1.48, anal shield slightly longer than wide, with ratio of length/width (at broadest level) ≃ 1.24; opisthogastric setae spatulate, except Jv1, Jv2, Zv1, and Zv2. Fixed digit of chelicera with 9–10 teeth of various sizes. Most of legs setae simple, except some spatulate setae on trochanter I, femur I–IV, and spine like av seta on femur II. In male, holoventral shield bearing 10 pairs of setae.

Description (adult female)

( Figures 68–83 )

Five specimens were measured.

Dorsal idiosoma ( Figure 68 , 73 & 75 ). Dorsal shield oval-shaped, 684–753 long, 456–506 wide, covering entire idiosoma dorsally; posterior part of shield with distinct scale-like reticulation, bearing 41 pairs of strongly curved, spatulate, and scimitar shaped setae (with a visible basal asymmetric protuberance) ( Figure 75 ), except j1 horse ear-like (31–43) and z1 spatulate acicular, without asymmetric protuberance (28–36): 22 pairs of podonotal setae, 19 pairs of ophisthonotal setae, and 10 unpaired supernumerary setae Jx between J1 and J4, dorsal setae mostly homogeneous in length, barely reaching base of next posterior setae (42–87), podonotal setae more curved and thickened than ophisthonotal setae. Shield with nine pairs of discernible pore-like structures, including five poroids (id4, id6, idm2, idm4, and idx) and three gland openings (gd2, gd5, and gd6).

Ventral idiosoma ( Figures 69 & 74 ). Tritosternum with paired pilose laciniae (101–122), columnar base 40–54 long × 8–11 wide; presternal area partly sclerotised, eyebrow-shaped, sternal shield 98–124 long, narrowest between coxae II (101–111), widest between coxae II and III (170–181), covered with reticulate ornamentation throughout, except central and posterior parts distinctly punctate, anterior margin of shield conspicuous, anterolateral corners narrowly extending between coxae I–II, posterior margin slightly concave. Shield bearing three pairs of long smooth setae (st1 57–65, st2 41–49, st3 35–40), not extending beyond next posterior setae, and two pairs of thin rectangular poroids (iv1 and iv2, mesal to setae st1 and between st2 and st3, respectively), metasternal setae st4 (32–42) and metasternal poroids (iv3) located on soft integument; endopodal elements between coxae II–III fused with shield and endopodal elements III–IV elongate, narrow, and curved. Genital shield flask-shaped, distinctly expanded laterally past level of setae st5, length 218–248, maximum width 151–164, posterior margin rounded, anterior margin of shield slightly convex, abutting posterior margin of sternal shield, surface reticulated with irregular, mostly longitudinal lines in anterior region, posterior part with irregular polygonal pattern, bearing a pair of simple setae st5 (41–47) 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 setae st5; anal shield pear-shaped, rounded anteriorly, 107–118 long, 87–98 wide, anterior half covered with lineate reticulation, para-anal setae (23–30) and post-anal seta (17–24) simple, cribrum consisting of a terminal tuft with some irregular rows of spicules and a pair of anterior arms extending to level between anal orifice and post-anal seta. Anal gland pores (gv3) on anterolateral margin of shield; soft opisthogastric cuticle surrounding genital, anal shields, and a pair of elongated metapodal plates (30–39 long × 5–8 wide), with two pairs of poroids (iv5, ivo) and 13 pairs of spatulate setae (19–29) (Jv3–Jv5, Zv3–Zv5, UR2, UR3, and R1–R5), except Jv1, Jv2, Zv1, and Zv2 setiform (19–31). Two 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); 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 70–72 & 76–79 ). Anterior margin of epistome convex, irregularly denticulate ( Figures 71 & 78 ); hypostomal groove considerably widened, with six transverse rows of denticles, each row with 17–33 tiny denticles, with smooth anterior and posterior transverse lines, groove wider anteriorly, progressively narrowing from anterior to posterior ( Figures 70 & 76 ). Hypostome with four pairs of smooth setae, h3 (53–70)> h1 (47–53)> pc (41–45)> h2 (21–27). Corniculi robust and horn-like, internal malae longer than corniculi, comprising a pair of pilose median projections, and 11–15 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; palpgenu with al1 and al2 stout, blunt, and thickened. Palptarsal apotele two-tined ( Figure 77 ); 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 ( Figure 72 & 79 ).

Insemination structures. Not seen, apparently unsclerotised.

Legs ( Figures 80–83 ). Leg II (471–533) and III (427–501) short, I (595–667) and IV (635–727) longer. Chaetotaxy normal for free-living Laelapidae : Leg I ( Figure 80 ): coxa 0-0/1, 0/1-0, trochanter 1-1/2, 0/1-1 (al spatulate), femur 2-2/1, 3/3-2 (pd2 and pd3 spatulate), genu 2-3/2, 3/1-2, tibia 2-3/2, 3/1-2. Leg II ( Figure 81 ): coxa 0-0/1, 0/1-0, trochanter 1-1/1, 0/1-1, femur 2-3/1, 2/2-1 (ad1, pd1, and pd2 spatulate, av spine-like), genu 2-3/1, 2/1-2, tibia 2-2/1, 2/1-2. Leg III ( Figure 82 ): coxa 0-0/1, 0/1-0, trochanter 1-1/1, 0/1-1, femur 1-2/1, 1/0-1 (ad1 spatulate), genu 2-2/1, 2/1-1, tibia: 2-1/1, 2/1-1. Leg IV ( Figure 83 ): coxa 0-0/1, 0/0-0, trochanter 1-1/1, 0/1-1, femur 1-2/1, 1/0-1 (ad1, ad2 spatulate), genu 2-2/1, 3/0-1, tibia 2-1/1, 3/1-2. 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 81–83 . All pretarsi with well-developed paired claws, rounded pulvilli and normal ambulacral stalk.

Description (adult male)

( Figures 84 & 85 )

Five specimens were measured.

Dorsal idiosoma. Dorsal shield 508–535 long, 347–372 wide; ornamentation and chaetotaxy as in female.

Ventral idiosoma ( Figure 84 ). Sternal, genital, endopodal, ventral and anal shields fused into holoventral shield, 391–409 long from anterior to posterior margins of shield, 95–107 wide at level of st2, 102–106 at st3 level and 249–268 at broadest point, posteriorly to coxae IV; shield reticulate throughout (ornamentation only partly drawn on Figure 84 ), 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, 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 12 pairs of spatulate setae. Peritremes, peritrematal shields, and other ventral structures similar to those in female.

Gnathosoma ( Figure 85 ). Fixed digit of chelicera with 11 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 (34–38). Other gnathosomal and cheliceral structures similar to those in female.

Legs. Chaetotaxy as in female.

Figures

FIGURES 68–72. Cosmolaelaps robustochaetes Ma & Lin, adult female: 68—Dorsal idiosoma; 69—Ventral idiosoma; 70— Ventral gnathosoma; 71—Epistome; 72—Chelicera.

FIGURES 73–79. DIC micrographs of Cosmolaelaps robustochaetes Ma & Lin, adult female: 73—Dorsal idiosoma; 74— Ventral idiosoma; 75—Some dorsal setae enlarged; 76—Ventral gnathosoma; 77—palp digit; 78—Epistome; 79—Chelicera.

FIGURES 80–83. Cosmolaelaps robustochaetes Ma & Lin, adult female: 80—Leg I; 81—Leg II; 82—Leg III; 83—Leg IV.

FIGURES 84–85. Cosmolaelaps robustochaetes Ma & Lin, adult male: 84—Ventral idiosoma; 85—Chelicera.