Gaeolaelaps kanati Joharchi & Issakova, 2020

Joharchi, Omid, Issakova, Aigerim K., Asyamova, Olga S., Sarcheshmeh, Mohammadhassan Abbasi & Tolstikov, Andrei V., 2020, Some soil-inhabiting mites (Acari: Mesostigmata) from Kazakhstan, with description of a new species of Gaeolaelaps Evans & Till (Acari: Laelapidae), Zootaxa 4819 (3), pp. 473-498 : 484-489

Gaeolaelaps kanati Joharchi & Issakova sp. nov.

( Figures 35–55 ).

Type material: Holotype, female, Kazakhstan, Kostanay Region , 53°15ʹN, 66°29ʹE, 10 October 2019, A.K. Issa-kova coll., from soil-litter (in TSUMZ) . Paratypes, three females, same data as holotype (in TSUMZ) .

Diagnosis (adult female). Dorsal shield 395–402 × 181–189 wide, reticulate throughout, narrowing from level of setae r3, progressively tapering until s6, then more or less parallel-sided from S1 to level of S4 until rounded posteriorly; with 38 pairs of smooth setae (except J4, J5 & Z5, sparsely barbed), z3 absent. All setae relatively short (20–25) excepting long r2 and Z5, not reaching base of next posterior setae. Presternal area lightly sclerotised, punctate, with a few transverse curved lines, sternal shield with reticulate ornamentation laterally, smooth (or faintly reticulated) medially, posterior margin slightly convex; ratio of shield length/width approx. 0.88. Genital shield, with length/width ratio approx. 2.4, with 7–8 cells posterior to inverted-V ridge. Anal shield with length/width ratio approx. = 1. Opisthosomal integument with seven pairs of smooth setae, peritremes short, reaching to mid-level of coxae II. Tarsus and femur IV with two (pd2, pd3) and one (ad1) elongated setae, respectively. Fixed digit of chelicera with seven teeth.

Description. Female (n=4)

Dorsal idiosoma ( Figs 35 , 42–44 ). Dorsal shield 395–402 long, 181–189 wide, covering most of dorsal idiosoma; shield distinctly reticulate ( Figs 35 , 42–44 ). Shield narrowing from level of setae r3, progressively tapering until s6, then subparallel from S1 to level of S4 until rounded posteriorly and with 38 pairs of setae: 21 pairs of podonotal setae, z3 absent, 17 pairs of opisthonotal setae, including two pairs Zx setae and r6 on lateral soft cuticle. All setae smooth (20–25) (except J4, J5 & Z5, sparsely barbed, see Fig. 44 ), j1 (20–22), z1 (14–16), r2 (37–39), J5, S5 (23–25), Z5 (32–34) ( Figs 35 , 42–44 ). Shield with about 20 pairs of discernible pore-like structures, including 16 poroids (id1, id2, id4–id6, idm1–idm6, is1, idx, idl1, idl3, idl4) and four gland openings (gd2, gd5, gd8, gd9), others indistinct, see Figures 35 , 42–44 .

Ventral idiosoma ( Figs 36 , 45–48 ). Tritosternum with paired pilose laciniae (65–67), fused basally (2–4), columnar base 25–27 × 13–15 wide; presternal area lightly sclerotised, punctate, with a few transverse curved lines, sternal shield length 101–110, maximum width 117–125, narrowest between coxae II (76–78), with reticulate ornamentation laterally, central part smooth (or faintly reticulated) ( Fig. 46 ), anterior margin almost straight but posterior margin slightly convex; bearing three pairs of smooth setae (st1 28–31, st2 25–27, st3 24–26), never reaching base of next setae, one pair of lyrifissures adjacent to setae st1, and a pair of poroids between st2 and st3. Metasternal setae st4 (21–23) and metasternal poroids located on soft integument; metasternal platelets absent. Endopodal plates II/III completely fused to sternal shield, endopodal plates III/IV elongate, narrow and curved. Genital shield tongue-shaped, slightly expanded posteriorly, past setae st5, length 130–140, maximum width 56–59, posterior margin rounded, surface reticulated with irregular, mostly longitudinal lines in anterior region, posteriorly with 7–8 cells enclosed behind an inverted-V shaped ridge; bearing a pair of simple setae st5 (19–21) ( Fig. 47 ). Shield flanked by two pairs of minute elongate paragenital platelets; paragenital poroids iv5 located on soft cuticle lateral to shield near seta st5. Anal shield subtriangular, rounded anteriorly, length 67–69, width 62–64, anterior half lineate-reticulate, para-anal setae and post-anal seta subequal in length (21–23), cribrum consisting of a terminal tuft with 3–5 irregular rows of spicules and a pair of anterior arms reaching level of posterior margin of anus ( Fig. 48 ); anal gland pores (gv3) on anterolateral margin of anal shield. Soft opisthogastric cuticle with pair of oval metapodal plates (21–23 long × 4–6 wide), an additional small round metapodal platelet more medially and seven pairs of smooth setae (Jv1–Jv5, Zv1–Zv 2) (19–24) and four pairs of poroids including iv5. Exopodal and parapodal platelets contiguous, surrounding coxa IV, strip-like, extending narrowly behind coxae IV. Peritreme extending anteriorly to mid-level of coxa II; peritrematal shield narrow, expanded anteriorly, fused to dorsal shield behind setae z1 level, free from exopodal shields, bearing five pore-like structures, a lyrifissure ip and a gland pore gp at level of coxa II, two lyrifissures ip and a gland pore gp on post-stigmatic section ( Fig. 51 ).

Gnathosoma ( Figs 37–40 & 49–50 ). Epistome subtriangular and irregularly denticulate ( Fig. 36 ). Hypostomal groove with six transverse rows of denticles, each row with 8–15 small denticles, with smooth anterior and posterior transverse lines, groove very slightly wider anteriorly. Hypostome with four pairs of setae, internal posterior hypostomal setae h3 (26–28), h1 (22–24), h2 (20–22), palpcoxal pc (20–22) ( Figs 37 & 49 ). Corniculi robust and horn-like, extending slightly beyond palptrochanter. Supralabral process with apically three-tined anterior projection ( Fig. 39 ). Internal malae with one pair of smooth median projections, flanked by lobes with fimbriate anterior margin; labrum with pilose surface ( Fig. 49 ). Chaetotaxy of palps: trochanter 2, femur 5, genu 6, tibia 14, tarsus 15, all setae smooth and needle-like except al1 and al2 on palpgenu and al on palpfemur thickened, palptarsal claw two-tined ( Fig. 50 ). Fixed digit of chelicera with an offset distal tooth (gabelzhan), followed by six variously sized teeth, a setaceous pilus dentilis, dorsal cheliceral setae prostrate, arthrodial membrane with a rounded flap and normal filaments; cheliceral lyrifissures indistinct; movable digit with two relatively large teeth ( Fig. 40 ).

Legs ( Figs 52–55 ). Legs II (276–281) and III, (240–244) short, I (385–410) and IV (366–369) longer. Chaetotaxy normal for free-living Laelapidae : Leg I ( Fig. 52 ): coxa 0–0/1, 0/1–0, trochanter 1–0/1, 1/2–1, femur 2–2/1, 3/3–2 (pd2 thickened), genu 2–3/2, 3/1–2, tibia 2–3/2, 3/1–2. Leg II ( Fig. 53 ): coxa 0–0/1, 0/1–0, trochanter 1–0/1, 0/2–1, femur 2–3/1, 2/2–1, genu 2–3/1, 2/1–2, tibia 2–2/1, 2/1–2 (all ventral setae thickened). Leg III ( Fig. 54 ): coxa 0–0/1, 0/1–0, trochanter 1–1/1, 0/1–1, femur 1–2/1, 1/0–1 (ad2 thickened), genu 2–2/1, 2/1–1 (all ventral setae and ad2 thickened), tibia: 2–1/1, 2/1–1 (all ventral setae thickened). Leg IV ( Fig. 55 ): coxa 0–0/1, 0/0–0, trochanter 1–1/1, 0/1–1, femur 1–2/1, 1/0–1 (ad2 and pd thickened; ad 1 (36–38) longest), genu 2–2/1, 3/0–1, tibia 2–1/1, 3/1–2 (pv thickened). Tarsi II–IV with 18 setae (3– 3/2, 3/2–3 + mv, md); with thickened some ventral and lateral setae, see Figures 53–55 . Tarsus IV with three noticeably long setae: pd2 (50–52) and pd3 (40–42) significantly longer than others, but ad2 barely longer than some tarsus IV setae. All pretarsi with well-developed paired claws, rounded pulvilli and normal ambulacral stalk.

Insemination structures ( Fig. 41 ). Laelapid-type sperm access system, tubulus long, wider at the solenostome level, mesad of coxa III, and entering sacculus. Proximal ends of the tubulus slightly swollen at junction with ramus, leading to circular-shaped sacculus.

Male and immatures. Unknown.

Etymology. This species is named after Mr. Kanat Kabdollievich Issakov, father of the second author.

Differential diagnosis. According to Vatankhah et al. (2016), the combination of short peritremes (reaching to middle of coxa II) and a dorsal shield with 38 pairs of setae occurs in only three described species of Gaeolaelaps : G. lenis Vatankhah & Nemati, 2016 , G. gleba ( Karg, 1979) , G. orientalis ( Hafez et al., 1982) . In both G. gleba and G. orientalis setae z3 is present and setae s1 and Zx3 are absent, respectively, while in G. kanati setae z3 absent. G. kanati most resembles G. lenis (couplet 15 in the identification key to Gaeolaelaps species with short peritremes provided by Vatankhah et al., 2016), due to the dorsal shield having 38 pairs of setae (z3 absent) and post-stigmatic plate small and extended to mid-level of coxa IV. Gaeolaelaps kanati differs from G. lenis by having an idiosoma 395–402 long (versus 566–571 in G. lenis ), dorsal shield distinctly reticulate throughout (versus smooth in anterior half in G. lenis ), J4 longer, almost reaching J5 insertion (versus J4 barely reaching more than half the J4–J5 distance, opisthonotal setae J4, J5 and Z5 sparsely barbed (apparently smooth in G. lenis ), sternal and genital shields distinctly reticulate (versus sternal and genital shields completely smooth in G. lenis ), anterior margin of sternal shield almost straight and clearly visible (versus anterior margin of sternal shield indistinct in G. lenis ), para-anal setae and post-anal seta subequal in length (versus post-anal seta distinctly longer than para-anal setae in G. lenis ). Gaeolaelaps kargi and G. praesternalis may be similar to G. kanati Joharchi & Issakova in general appearance, but G. kargi and G. praesternalis have a long peritreme nearly extending to coxa I. In the classification of Karg (1982), G. lankaensis falls into the similisetae species group of Hypoaspis (Gaeolaelaps) , due to short peritreme that extend to the middle of coxa II, but it is distinguished from all species of the similisetae species group by the following combination of characters: (1) dorsal shield reticulate throughout, narrowing from level of setae r3 and with 38 pairs of setae (z3 absent); (2) palptarsal claw two-tined; (3) sternal and genital shields with reticulate ornamentation; (4) tarsus and femur IV with two (pd2, pd3) and one (ad1) elongated setae, respectively; (5) fixed digit of chelicera with 7–8 teeth.

Figures

FIGURES 35–41. Gaeolaelaps kanati Joharchi & Issakova sp. nov., female. 35, dorsal idiosoma; 36, ventral idiosoma; 37, subcapitulum; 38, epistome; 39, supralabral process; 40, chelicera; 41, insemination structures.

FIGURES 42–48. DIC micrographs of Gaeolaelaps kanati Joharchi & Issakova sp. nov., female. 42, idiosoma in dorsal view; 43, reticulation of podonotal area of the dorsal shield, general view of some dorsal setae; 44, reticulation of opisthonotal area of the dorsal shield, general view of some dorsal setae; 45, idiosoma in ventral view; 46, sternal shield; 47, genital shield; 48, anal shield.

FIGURES 49–51. DIC micrographs of Gaeolaelaps kanati Joharchi & Issakova sp. nov., female. 49, subcapitulum; 50, palp, enlarged section of palp-apotele not to scale; 51, posterior portion of peritrematal shield.

FIGURES 52–55. DIC micrographs of Gaeolaelaps kanati Joharchi & Issakova sp. nov., female. 52, leg I (trochanter-tibia); 53, leg II; 54, leg III; 55, leg IV.