Gymnolaelaps prestoni, Joharchi, Omid, Halliday, Bruce, Saboori, Alireza & Kamali, Karim, 2011

Joharchi, Omid, Halliday, Bruce, Saboori, Alireza & Kamali, Karim, 2011, New species and new records of mites of the family Laelapidae (Acari: Mesostigmata) associated with ants in Iran, Zootaxa 2972, pp. 22-36 : 26-28

Gymnolaelaps prestoni sp. nov.

( Figures 10–18 )

Specimens examined. Holotype, female, Iran, Karaj, 35˚57’ N, 51˚21’ E, alt. 2130 m, 30 March 2010, O. Joharchi coll., in nest of Myrmica sp. Paratypes. Three females, same data as holotype (one in JAZM, two in ANIC).

Description. Female.

Dorsal idiosma. Dorsal shield length 748–775 µm, width 571–609 µm (n = 4) ( Fig. 10 ). Shield oval-shaped, surrounded by a narrow strip of unsclerotised skin; dorsal shield with weak reticulation, more distinct posterior to setae J1; with 22 pairs of podonotal setae, 17 pairs of opisthonotal setae including two pairs of Zx setae between J and Z setae, and one unpaired Jx seta; setae increasing in length from anterior to posterior (j 1 20–22 µm, J5 79–84 µm). All dorsal setae slightly serrated ( Fig. 11 ). Central area of shield with four pairs of large circular to ovalshaped pores, outer area with approximately ten pairs of small inconspicuous circular pores.

Ventral idiosoma ( Fig. 12 ). Tritosternum with paired pilose laciniae (99–111 µm) columnar base 42–45µm long; pre-sternal shields with sclerotised postero-lateral section bearing one or two transverse lines, antero-medial section weakly sclerotised. Sternal shield (length 149–156 µm) narrowest between coxae II (156–158 µm), widest between coxae II and III (257–267 µm), with straight anterior margin and concave posterior margin, with three pairs of smooth sternal setae (st 1 50–54 µm, st 2 50–54 µm, st 3 50–54 µm), one pair of lyrifissures adjacent to setae st 1, and a pair of large circular pores between st 2 and st 3; antero-lateral surface of sternal shield with polygonal ornamentation, central area smooth. Metasternal platelets absent; setae st 4 and associated pores located in soft skin; endopodal plates II/III fused to sternal shield; endopodal plates III/IV free, very long and narrow. Genital shield broad, length 386–407 µm, maximum width 222–256 µm, posterior edge straight, abutting anal shield, surface with polygonal ornamentation, bearing the genital setae st 5 and three pairs of setae on its lateral edges. Circular paragenital pores located on soft skin lateral to shield between seta st 5 and Jv1. Anal shield triangular (129–136 µm long × 156–160 µm wide), its anterior half with lineate ornamentation and a pair of small circular lateral pores; para-anal setae (37–40 µm) twice as long as unpaired post-anal seta (20–24 µm). Opisthogastric skin with one pair of oval metapodal plates (length 39–44 µm) and 8 pairs of smooth pointed setae (Jv1 50–52 µm, Jv2 42–44 µm, Jv3 37–39 µm, Jv5 84–86 µm, Zv1 42–44 µm, Zv2 42–44 µm). Large triangular podal shields present posterior to coxae IV, similar in texture and appearance to other ventral sclerites. Peritreme extending from coxa IV to midlevel of coxa I, peritrematal shield wide, outer margin smoothly curved, post-stigmatal section conspicuous, with three pairs of post-stigmatal pores, and one pair of pores anterior to the stigmata.

Gnathosoma . Hypostomal groove with six rows of denticles each bearing 4–6 small teeth, and smooth anterior and posterior transverse lines ( Fig. 13 ). Corniculi robust and horn-like, reaching mid-level of palp femur. Internal malae complex, with three pairs of lobes; inner lobes narrow, with serrated edges; medial lobes less than half length of inner lobes, with strongly serrated edges; outer lobes long, narrow, pointed, with some serration at base of medial margin. Palp chaetotaxy: trochanter 2, femur 5, genus 6, tibia 14, tarsus 15; genu with a distinct dorso-distal triangular condyle, all setae smooth and needle-like; palp tarsal claw with three pointed tines of unequal lengths ( Fig. 14 ). Epistome irregularly denticulate ( Fig. 15 ). Fixed digit of chelicera with a small triangular tooth, a larger median tooth, and two small distal teeth ( Fig. 16 ); pilus dentilis long and robust; dorsal seta short, thick, prostrate; movable digit with two large teeth; arthrodial membrane with a rounded flap and a few short filaments.

Legs. Legs II and III short (653–710 µm, 633–690 µm), I and IV longer (870–940 µm, 940–960 µm). Chaetotaxy: Leg I: coxa 0 0/1 0/1 0, trochanter 1 1/2 0/1 1 (ad long and thick), femur 2 3/2 2/2 2, genu 2 3/2 3/1 2, tibia 2 3/2 3/1 2. Leg II: coxa 0 0/1 0/1 0, trochanter 1 0/1 0/2 1, femur 2 3/1 2/2 1 (al 1 thick), genu 2 3/1 2/1 2 (ventral setae thick), tibia 2 2/1 2/1 2 (ventral setae thick). Leg III: coxa 0 0/1 0/1 0, trochanter 1 1/1 0/1 1 (ad very long and thick, 58–65 µm), femur 1 2/1 1/0 1, genu 2 2/1 2/1 1 (al 2 47 µm, ad 1 50 µm, av and pv long and thick, 37 µm), tibia 2 1/1 2/1 1 (pv long and thick) ( Fig. 17 ). Leg IV: coxa 0 0/1 0/0 0, trochanter 1 1/1 0/1 1 (ad long and thick), femur 0 2/1 1/1 1 (pd thick), genu 2 2/1 3/0 1 (ad 1 50 µm, pl 50 µm, a v long and thick, 50 µm), tibia 2 1/1 3/1 2 (ventral setae long and thick) ( Fig. 18 ). Tarsi I–IV with 18 setae 3 3/2 3/2 3 + mv, md. All pre-tarsi with a pair of claws and a long thin membranous ambulacrum.

Insemination structures not seen, apparently unsclerotised.

Etymology. This species is named in honour of Preston Hunter, who made important contributions to the systematics of free-living Laelapidae .

Notes. Gymnolaelaps prestoni differs from almost all other species in the genus by the pair of large circular pores on the sternal shield between setae st 2 and st 3. In most species a pair of slit-shaped lyrifissures occurs in this position. Only five other species in the genus have large circular pores between setae st 2 and st 3. Gymnolaelaps prestoni differs from G. shealsi Hunter & Costa, 1971 and G. submyrmecophila Xu & Liang, 1996 by the presence of large subtriangular exopodal plates behind coxa IV (absent or very small in G. shealsi and G. submyrmecophila ). It differs from G. myrmecophilus ( Berlese, 1892) , G. sitalaensis Bhattacharyya, 1966 and G. messor by the presence of two pairs of Zx setae on the dorsal shield between the J and Z series setae, and by its longer dorsal shield setae. Gymnolaelaps myrmecophilus has much shorter opisthonotal setae than G. prestoni , while G. sitalensis has three pairs of Zx setae and short dorsal shield setae. Gymnolaelaps prestoni is similar to G. reniculus Karg, 1981 , but differs from it by having only 17 pairs of opisthonotal setae (22 pairs in G. reniculus ).

Figures

FIGURES 10 – 18. Gymnolaelaps prestoni sp. nov., female. 10. dorsal shield; 11. opisthosomal seta enlarged; 12. ventral idiosoma; 13. hypostome; 14. palp tarsal claw; 15. epistome; 16. chelicera; 17. genu III, dorsal aspect; 18, genu and tibia IV, dorsal aspect. Scale bar = 100 μm for 10 and 12, 50 μm for 13, 15, 16, 17, 18; 10 μm for 14. Figure 11 not to scale.