Gaeolaelaps khajooii Kazemi, Rajaei & Beaulieu

Kazemi, Shahrooz, Rajaei, Asma & Beaulieu, Frédéric, 2014, Two new species of Gaeolaelaps (Acari: Mesostigmata: Laelapidae) from Iran, with a revised generic concept and notes on significant morphological characters in the genus, Zootaxa 3861 (6), pp. 501-530 : 510-514

Gaeolaelaps khajooii Kazemi, Rajaei & Beaulieu sp. nov.

( Figs 13–28 )

Diagnosis (based on adult female). Dorsal shield clearly broadest at level of setae r3 (ratio of widths at r3 / S3 level≈1.5), progressively tapering until s6, subparallel from s6 to level of S4, rounded posteriorly; with 39 pairs of mostly smooth and moderately long setae; an additional, median unpaired seta may be present between J4–5; gland pores gd2 and gd6 absent; three pairs of marginal setae present on lateral soft cuticle. Sternal shield longer than wide (ratio of length/width≈1.3), reticulate throughout, its anterior margin with or without a small median invagination; posterior margin slightly convex, with two minute projections. Epigynal shield tongue-shaped, very slightly broadened posteriorly. Anal shield subtriangular, with two single files of denticles reaching level of paraanal setae; anal shield separated from epigynal by about length of anal shield. Peritremes relatively short, anteriorly reaching mid-level of coxae II. Post-stigmatic area of peritrematal shield narrowly extended to posterior edge of coxae IV. Opisthogastric and dorsolateral soft integument bearing seven and three pairs of setae, respectively.

Deutosternal groove with six rows of 10–17 denticles. Internal malae with a pair of long median projections and a pair of shorter lateral projections. Palp apotele 2-tined. Fixed digit of chelicera with 10–13 teeth, including a serrated row of 6–9 small teeth posterior to pilus dentilis. Leg setae simple and slender, except following setae thickened and/or spine-like: ad3 (only slightly thickened) on femur I; av on femur II; pd on femur IV; all ventral setae on genua and tibiae II-IV (some only slightly thickened), and pl1 on tibia IV; md, av1–2, mv and pv1–pv2 on tarsus II; al1, av1–2, pv1–2, pl1 (slightly thickened), md and mv on tarsus III; pl2 (slightly thickened), av2, pv2 and mv on tarsus IV; pd2–3 on tarsus IV slender and elongate.

Description. Female (n=3). Dorsal idiosoma ( Fig. 13 ). Idiosoma length 541–552, width 301–307. Dorsal shield 489–522 long, 203–213 wide at j6 level, covering most of dorsal idiosoma, 248–253 wide at level of r3 and 163–170 at level of S3; reticulate throughout except anteromedially; with 39 pairs of needle-like setae of which some of the most posterior pairs (e.g. J4–5, Z5, Jx) have a few minute barbs; 0–1 unpaired median seta Jx between setae J4-J5. Dorsal shield setae j 1–5 32–36, j 6 28–31, z 1 23–28, z 2 31–32, z3 33–34, z4 34–38, z5 34–36, z 6 28–30, s 1 22 –23, s 2 24 –27, s3 35 –40, s 4 29 –35, s 5 28 –31, s 6 29 –36, r 2 31–35, r3 38–45, r 4 31–34, r 5 29–34, J 1–5 27–31, Jx 28–30, Z 1 28–31, Z 2–3 24–29, Z 4 28–30, Z5 38–44, S 1–4 29–34, S5 33 –39 long. Setae R1 (29–31), R4 (30–33) and R5 (34–38), and a pair of poroids (idR3) on lateral soft integument. Dorsal shield with 16 pairs of poroids and only four pairs of gland pores (gd2 and gd6 pores absent).

Ventral idiosoma ( Figs 14, 16–17 ). Tritosternum with a narrow columnar base, 32–36 long, 14–17 wide at base, 7–9 wide at apex, and two sparsely pilose laciniae, length free for 90–95 and fused basally for 2–4 µm. Presternal area lightly sclerotised and punctate, with a few transverse lines. Sternal shield 154–160 long, 114–118 wide, reticulate throughout; anterolateral corners narrowly extending between coxae I-II; anterior margin irregularly straight, with or without a small median invagination; posterior margin slightly convex, with two minute projections near medial axis, which may represent vestiges of gland pore gv1 ( Figs 16–17 ); shield bearing three pairs of smooth setae st1 (38–39), st2 (37–38) and st3 (34–36), and two pairs of poroids, lyrifissures iv1 slitlike and oriented obliquely, iv2 suboval. Metasternal setae (27–30) and poroids iv3 on soft cuticle. Endopodal elements between coxae III–IV narrow, anteriorly free from sternal shield. Epigynal shield 185–190 long, 92–95 from st5 level to posterior margin, 69–71 wide, 58–62 wide at narrowest point (near coxae IV level), and 81–83 at broadest point past setae st5; anterior hyaline margin irregular, not covering posterior area of sternal shield; surface reticulated with an inverse Y–shaped pattern, with the Y posteriorly embracing eight large cells; setae st5 (27–29) inserted on lateral margins of shield at level of posterior margin of coxae IV, and poroids iv5 inserted laterad of st5. Anal shield subtriangular, anteriorly rounded, 74–80 long, 74–80 wide, anterior margin gently rounded, and surface lineate-reticulate; circumanal setae smooth, postanal seta (35–38) longer than para-anal setae (29–31), cribrum well developed, narrowly extending laterally to level of adanal setae; anus located slightly posterior to mid-level of shield; pair of glands gv3 inserted on lateral margins of shield at level of anterior margin of anus. Peritrematal shields well developed anteriorly and fused narrowly to dorsal shield at level of z1, with a narrow strip of granular cuticle parallel to anterior edge of shield; between stigmata and coxa II, shield almost limited to a relatively narrow band of cuticle at level between coxae II and III, bearing a poroids and a gland pore; post-stigmatic region of shield narrowly extending to posterior level of coxae IV, bearing two and one gland pore; an additional pore located on peritrematal shield at level of seta s1. Peritremes relatively short (178–182) and narrow, extending from stigmata to mid-level of coxae II. Three exopodal platelets between coxae I-II, II-III and III-IV present, anterior two platelets small and subtriangular, those between coxae III-IV slightly extending posteriorly; parapodal platelets strip-like, bearing gland pore gv2. Opisthogastric integument with two pairs of small, narrow paragenital platelets between st5 and ZV1, and two pairs of narrow metapodal platelets, the smallest at or above level of ZV1 and the largest one near level of JV1; seven pairs of ventral opisthogastric setae JV1 (19–23), JV2 (18–22), JV3 (24–26), ZV1 (23–28) and ZV2 (27–31) smooth; JV4 (28–32), JV5 (44–49) with 1–2 minute barbs; and five pairs of poroids.

Gnathosoma ( Figs 20–24 ). Anterior margin of epistome convex and finely denticulate, with about 30 denticles ( Fig. 20 ). Corniculi horn-like (58–64). Internal malae fringed, slightly longer than corniculi, with a pair of long median projections and a pair of shorter lateral projections. Labrum acuminate, considerably longer than internal malae. Hypostomal and capitular setae smooth, h1 (50–51)> h3 (35–38)> h2 (34–35)≈ pc (32–35). Deutosternal groove with six rows of denticles, progressively broader from posterior to anterior, each with 9–17 denticles; anteriormost row angled medially. First cheliceral segment 58–67 long, second segment 190–196 long and 54–56 wide; fixed digit 73–75 long, with 10–13 teeth, including (from distal to proximal) a subapical large offset tooth (gabelzhan) followed by two other teeth, one small and one large, anterior to the short, setiform pilus dentilis, and 6–9 smaller, tightly aligned teeth followed posteriorly by a larger tooth; movable digit of chelicera 85–87 long, bidentate; dorsal cheliceral seta short and setiform ( Fig. 22 ). Palp chaetotaxy normal for Laelapidae , all setae smooth; palpgenu setae al1 and al2 slightly thick and spatulate, palpfemur al slightly thick and spine-like; palp apotele 2-tined ( Figs 23–24 ).

Legs ( Figs 25–28 ). All legs with ambulacrum, that of leg I longer (35–36) than those of legs II-IV (24–26) ( Figs 18–19 ), lengths of legs I-IV as follows: 591–597, 425–451, 384–392, 582–605, respectively. Lengths of femora I 104–111, II 85 –96, III 75 –77, IV 117–123; genua I 83 –87, II 69 –70, III 50 –53, IV 89 –92; tibiae I 95 –97, II 66 –67, III 51 –53, IV 96 –98; tarsi I 156–163, II 108–115, III 105–110, IV 156–160. Leg chaetotaxy normal for Laelapidae (sensu Evans & Till, 1965) and Gaeolaelaps (see Beaulieu, 2009). Most setae simple, needle-like and of similar length, except a few shortened, elongate or thickened setae: trochanter I with al short and slightly thickened; trochanter II with al1 thickened; trochanter IV with pv1 slightly thickened; femur I with ad3 slightly thickened, femur II with av somewhat spine-like and al2 very short, slightly thickened; femur IV with pd spinelike, ad2 slightly thickened, and pl short and thin; genu II with av short and spine-like, and genua III-IV with ventrals slightly thickened; tibia II with av1 spine-like, pv1 thickened; tibia III and IV with pv spine-like, av slightly thickened; pl also spine-like on tibia IV; tarsus II with av1–2, md, mv, and pv1–2 spine-like; tarsus III with md and mv spine-like, and av1–2, pv1–2 slightly thickened; tarsus IV with pl2 slightly thickened, mv, av2 and pv2 thickened, and pd2 and pd3 slender and elongate with pd2 longer than half the length of tarsus. Coxa I bearing two gland pores (gc) ( Fig. 14 ).

Material examined. Holotype: female southern Iran, Kerman Province, Baft County (28˚39' 46" N; 56˚45' 37" E), altitude 1044 m above sea level, from soil and litter at an alfalfa farm, 2 April 2012, coll. A. Rajaei, deposited in ACISTE. One paratype female with same collection data, deposited in ACISTE; another paratype female with same collection data, deposited in CNC.

Etymology. The species is named in honour of the famous Persian poet, Khajooi-e Kermani.

Remarks. The new species can be placed in the similisetae species group (sensu Karg, 1979) based on its short peritremes reaching only the mid-level of coxae II, and differs from other species of the group by the shape of the dorsal shield, which is clearly widest at the level of setae r3 and tapers posteriorly. This shape is reminiscent of the G. angusta species group, but differs from most members of that group by its dorsal shield with almost parallel sides in the opisthonotal region (from S1 to S4). The species most similar to G. khajooii is G. zhoumanshuae ( Ma, 1997) , which, justifiably, was classified in the angusta species group by Nemati & Kavianpour (2013). In addition to the very similar shape of their dorsal shield, G. zhoumanshuae and G. khajooi both have peritremes shortened anteriorly, ending before the anterior margin of coxae II, seven opisthogastric setae (six in G. zhoumanshuae , but JV 5 may have been illustrated dorsally), three dorsomarginal (R) setae (four in G. zhoumanshuae , perhaps including JV5 dorsally), and have a cheliceral fixed digit with a serrated row of small teeth proximally to the pilus dentilis (based on figures in Ma, 1997). Gaeolaelaps khajooii differs from it at least by having 39 pairs of setae on the dorsal shield, including Px2–3, which are absent in G. zhoumanshuae . The new species also resembles Hypoaspis (sensu lato) atomarius Berlese, 1917 (sensu Van Aswegen & Loots, 1970), which has a similar dorsal shield albeit posteriorly wider, but it can be easily distinguished from H. atomarius by having one ventral setae on genu IV (two ventrals in G. atomarius ) and 39 setae on dorsal shield (38 in G. atomarius , with z3 absent).

The two minute projections on the posterior margin of the sternal shield are unusual, but also occur in other Gaeolaelaps species, including G. jondishapouri , G. nolli ( Karg, 1962) , G. praesternalis ( Willmann, 1949) and G. farajii , and an undescribed species that have dorsal shield shaped similarly to G. khajooii . It is possible that these minute projections represent the vestiges of gland pores gv1.

Figures

FIGURES 13 – 19. Gaeolaelaps khajooii Female. 13. Dorsal idiosoma; 14. Ventral idiosoma; 15. Details of some dorsal shield setae; 16 – 17. Sternal shield; 18. Ambulacrum II; 19. Ambulacrum I.

FIGURES 20 – 24. Gaeolaelaps khajooii Female. 20. Epistome; 21. Subcapitulum; 22. Chelicera; 23. Palp, trochanter to genu; 24. Palptarsus, showing apotele and setal sockets.

FIGURES 25 – 28. Gaeolaelaps khajooii Female. 25 – 28. Legs I-IV, dorsal view.