Gaeolaelaps orbiculatus, Nemati, Alireza & Mohseni, Mastaneh, 2013

Nemati, Alireza & Mohseni, Mastaneh, 2013, Two new species of Gaeolaelaps (Acari: Laelapidae) from Iran, Zootaxa 3750 (1), pp. 71-82 : 76-79

Gaeolaelaps orbiculatus sp. n.

( Figures 12–20 )

Specimens examined. Holotype, female, Iran, Khuzestan province, Izeh (31° 49´52" N, 49° 52´9" E, alt. 845 m), from soil, coll., A. Nemati, 2012 (in Acarological Laboratory of Shahrekord University, Chaharmahal Va Bakhtiari province, Iran). One female paratype, same data as holotype (in Senckenberg Museum fur Naturkunde Gorlitz Am Museum 1 0 2826 Gorlitz Germany).

Description. female

Dorsal idiosoma. Dorsal shield length 489–491 Μm, width 270–276 Μm (n = 2) ( Fig. 12 ). Shield oval shaped, distinctly slerotised, with distinct polygonal ornamentation throughout, with 39 pairs of short setae, 22 podonotal, 17 opisthonotal, including two pairs of Px setae between J and Z setae, setae nearly equal in length (15–20 Μm), Z5 longest (25–26 Μm). Setae r6, R5 and Jv5 located on lateral integument between dorsal and ventral surfaces. Podonotal and opisthonotal regions with 20 pairs of pore-like structures, each with 10 pairs ( Fig. 12 ).

Ventral idiosoma ( Fig. 13 ). Tritosternum with columnar base 31–34 Μm long, and paired pilose laciniae (60 Μm). Granulated pre-sternal area with well sclerotised ovoid pre-sternal plates, ornamented with lines. Sternal shield (127–130 Μm long) narrowest between coxae II (98–109 Μm), widest between coxae II and III (133–135 Μm), with slightly convex anterior margin and irregular convex posterior margin, with three pairs of smooth sternal setae (st 1 = 29 Μm, st 2 = 26 Μm, st 3 = 23–26 Μm), one pair of lyrifissures (iv1) adjacent to setae st 1, and a pair of circular pores (iv2) between st 2 and st 3; sternal shield with ornamentation throughout except posterior area behind st3 smooth. Setae st 4 (23 Μm) and associated pores (iv3) located on soft skin; endopodal plates II/III fused to sternal shield, endopodal plates III/IV elongate, narrow, angular and extending to the posterior level of coxa IV. Tongue-shaped genital shield 140–143 Μm long (excluding hyaline flap), 68 Μm wide, ratio of length to width (L/ W) 2.07–2.11, at widest point narrower than anal shield, bearing the genital setae (st5 = 18–21 Μm), surface reticulate, with a pair of inverted v-shaped lines enclosing eight cells. Circular paragenital pores located on soft skin between seta st 5 and coxa IV. Anal shield sub-circular, wider than genital shield (75–78 Μm long × 86–89 Μm wide), its surface ornamented, with a pair of circular lateral pores, para-anal setae (18–21 Μm) and unpaired postanal seta (18 Μm). Opisthogastric surface with one pair of suboval metapodal plates, one pair of narrow, slightly elongate paragenital platelets, six pairs of smooth setae (Jv1 – 4, Zv1 – 2 with 19–26 Μm long), and five pairs of porelike structures. Peritreme extending from anterior level of coxa IV to anterior level of coxa II; peritrematal shield wide, with a longitudinal line that creates a bulge-like section at level of coxa II–III which encompasses a pore-like structure, one lyrifissure (ip) and glandular poroid (gp) located on its anterior part ( Fig. 14 ). Stigmata located between coxa III–IV, post-stigmatal plate extending nearly to middle part of coxa IV, with three pores, and one pore just anterior to the stigmata. Exopodal plates like small fragments and angular, anterior to coxa I, between coxae II–III; between coxae III–IV, and narrow, crescent-shaped podal plates around coxa IV that extend to near the posterior tip of the narrow angular endopodal platelet mesad coxae III–IV.

Gnathosoma . Hypostome ( Fig. 15 ) with three pairs of smooth simple setae; h1 (29 Μm), h2 (23–26 Μm) and h3 (16–18 Μm). Palpcoxal setae 16–18 Μm long. Deutosternal groove with six rows of seven to nine denticles, and smooth anterior and posterior transverse lines ( Fig. 15 ). Corniculi normal, horn-like. Internal malae with two pairs of lobes: inner lobes narrow, pointed, and separated, outer lobes very small, with four small threads between inner and outer lobes. Epistome denticulate, with a two tined medioventral process projecting beyond the anterior margin ( Fig. 16 ). Fixed digit (60–62 Μm) of chelicerae with three large proximal teeth and a small distal tooth, pilus dentilis thin and setaceous, dorsal seta short, movable digit (52–57 Μm) with two large teeth ( Fig. 17 ), arthrodial process with a row of moderately short filaments. Palp ( Fig. 18 ) with normal setation, palp-tarsal claw two-tined, basal tine shorter, seta al1 on palp-genu rod-like and seta al2 thickened and similar to al on the femur ( Fig. 18 ).

Legs. Tarsi I–IV with claws and ambulacra. Legs I and IV longer than legs II and III. Leg I 439–452 Μm, coxa (62–70 Μm), trochanter (39–44 Μm), basi-femur (21–23 Μm), telo-femur (60–68 Μm), genu (65–68 Μm), tibia (68 Μm), tarsus (117–120 Μm); Leg II 330–348 Μm (excluding stalk and pretarsus), coxa (36–47 Μm), trochanter (42–44 Μm), basi-femur (18 Μm), telo-femur (39–52 Μm), genu (57–60 Μm), tibia (47–52 Μm), tarsus (83 Μm); Leg III 278 (excluding stalk and pretarsus), coxa (26–29 Μm), trochanter (47–49 Μm), basi-femur (16–23 Μm), telo-femur (39– 47 Μm), genu (31–36 Μm), tibia (34–36 Μm), tarsus (70–73 Μm); Leg IV 408–432 Μm (excluding stalk and pretarsus), coxa (36–42 Μm), trochanter (70–78 Μm), basi-femur (23–31 Μm), telo-femur (65–68 Μm), genu (49–52 Μm), tibia (55 Μm), tarsus (104–112 Μm). Chaetotaxy of all leg segments normal for Gaeolaelaps (sensu Beaulieu, 2009). All setae fine and needle-like unless otherwise noted. Chaetotaxy of legs is similar to that of G. farajii sp. n., setae al1 and pl1 on tarsus of leg II ( Fig. 19 ) and IV ( Fig. 20 ); ad1, ad2 and pd on femur IV ( Fig. 20 ) and all ventral setae slightly thickened; setae pd2 – 3 on tarsus IV, al3 on tarsus II and ad1 on femur IV slightly longer than the other setae on those segments.

Insemination structures: not seen, apparently unsclerotised.

Remarks: Karg (1979) has defined a similisetae species group including species that have short peritremes that extend to the middle of coxa II or at most to anterior margin of coxa II. Karg (2006) considered nine species in this group: G. macra (Karg, 1978) , G. gleba (Karg, 1979) , G. vertisimilis (Karg, 1994) , G. verticis (Karg, 1979) , G. cerata (Karg, 1982) , G. loksai (Karg, 2000) , G. latopuga (Karg, 2006) , G. nolli (Karg, 1962) , and G. similisetae (Karg, 1965) . However, our literature review revealed further species with short peritremes: G. carabidophilus Trach, 2012 , G. zhoumanshuae (Ma, 1997) , G. orientalis (Hafez et al., 1982) , G. dailingensis (Ma & Yin, 1998), G. bregetovae (Shereef & Afifi, 1980) , G. arabicus (Hafez et al., 1982) , G. koseii (Hafez et al., 1982) , and G. orbiculatus sp. n. In most of these species the peritreme extends to the middle of coxa II, except for G. macra and G. orbiculatus , in which the peritremes extend to the anterior level of coxa II.

Gaeolaelaps orbiculatus may be differentiated most readily by the following combination of characters – the presence of short peritremes extending to the anterior margin of coxa II; anal shield nearly rounded, reticulated, wider than epigynal shield; dorsal shield completely reticulated; and the presence of seven pore-like structures on the peritrematal shield, post-stigmatal plate and on the peritreme just anterior to stigmata. Gaeolaelaps orbiculatus is similar to G. macra in having the peritremes extending to the anterior margin of coxa II, but it may be readily differentiated by the following characters – G. macra has 41 pairs of setae on dorsal shield; anal shield subtriangular and longer than wide; genital shield remarkably longer than wide, length/width= 3:1; dorsal setae nearly equal in length (28–33 Μm); idiosoma 400–480 Μm long, 180–220 Μm wide, while in G. orbiculatus the dorsal shield has 39 pairs of setae; the anal shield is nearly rounded and wider than long; the epigynal shield is not as above, length/width= 2:1; the dorsal setae are nearly equal in length (15–20 Μm); and the idiosoma is 489–491 Μm long, 270–276 Μm wide.

Male. Unknown.

Etymology. The name of this species is referred to its sub-circular anal shield.

Figures

FIGURES 12 – 14. Gaeolaelaps orbiculatus sp. n., Female: 12, dorsal shield; 13, ventral idiosoma; 14, peritreme.

FIGURES 15 – 20. Gaeolaelaps orbiculatus sp. n., Female: 15, hypostome; 16, epistome; 17, chelicera; 18, palp; 19, tarsus II; 20, leg IV.