Myrmozercon crinitus Joharchi

Joharchi, Omid & Moradi, Maryam, 2013, Review of the genus Myrmozercon Berlese (Acari: Laelapidae), with description of two new species from Iran, Zootaxa 3686 (2), pp. 244-254 : 245-248

Myrmozercon crinitus Joharchi sp. nov.

( Figures 1–13 )

Specimens examined. Holotype, female, Iran, Alborz, Karaj, 35˚48’ N, 50˚59’ E, alt. 1550 m, 10 April 2011, M. Moradi coll., clinging to the head of soldiers of Pheidole pallidula (Formicidae) (in YIAU). Paratypes, six females, two males, same data as holotype (four females and two males in YIAU and JAZM, two females in ANIC).

Description. Female. Dorsal idiosoma. Dorsal shield length 718–752, width 496–580 (n = 5) ( Fig. 1 ), oval shaped, without reticulation, extending to end of idiosoma, hypertrichous, with approximately 450 setae, all setae smooth and moderate in length (17–32). Lateral setae longer than those in centre of shield, pores inconspicuous.

Ventral idiosoma ( Fig. 4 ). Tritosternum 74–84 long, with columnar base (27–30) and paired pilose laciniae 52– 62 long ( Fig. 6 ). Pre-sternal shields absent. Sternal shield length 178–184, narrowest between coxae II (158–164), widest between coxae II & III (228–232), with slightly concave posterior margin; with three pairs of smooth sternal setae, lengths st 1 40–47, st 2 35–45, st 3 42–50, one pair of lyrifissures adjacent to setae st 1, another pair of larger lyrifissures between st 2 and st 3; surface of shield smooth. Metasternal platelets absent, metasternal

setae st 4 (30–32) and metasternal pores located in soft skin; endopodal plates II/III fused to sternal shield, endopodal plates III/IV elongate, narrow, curved. Genital shield wide, length 258–272, maximum width 208–222, posterior edge rounded, surface without ornamentation, bearing the genital setae st 5 (42–47). Paragenital pores located on soft skin lateral to shield between seta st 5 and coxae IV. Opisthogastric integument with extra irregularly-shaped area of sclerotisation connecting the genital and anal shields, partly surrounding genital shield and completely surrounding anal shield. Anal shield subtriangular, length 100–104, width 100–108, its surface smooth, anal pores indistinct; post-anal seta (15–17) shorter than para-anal setae (22–25). Opisthogastric skin with two pair of irregular metapodal plates and approximately 34 pairs of setae (17–32), 4–5 pairs of setae on extra sclerotisation between genital and anal shields. Peritreme very short, with only a tiny section of peritreme on the anterior side of the stigmata, peritrematal shield very wide, reaching to anterior level of coxa I, post-stigmatal section conspicuous and very wide.

Gnathosoma . Hypostomal groove with eight rows of denticles, 8 to 15 very fine denticles per row, four rows sloping, not transverse ( Fig. 3 ). Hypostomal setae h1 and h3 longer than h2, surface of hypostome ornamented with transverse and curved lines. Palp chaetotaxy: trochanter 2, femur 5, genu 6, tibia 12, tarsus 15; all setae smooth and needle-like, palp tarsal claw two-tined ( Fig. 5 ). Epistome triangular, smooth, apex irregularly denticulate ( Fig. 4 ).

Fixed digit of chelicera edentate, with a low median bulge, shorter than movable digit; dorsal seta short, prostrate; movable digit weakly sclerotised, distally curved; arthrodial membrane with a rounded flap and a few short filaments ( Fig. 7 ). Corniculi short, broad, weakly sclerotised.

Legs. ( Figs 10–13 ). Legs II and III short (550–570, 534–554), IV longer (768–788) and leg I longest (1114– 1168) (without pre-tarsus). Chaetotaxy: Leg I: coxa 0 0/1 0/1 0, trochanter 1 1/1 1/2 1, femur 2 3/2 2/3 2, genu 3 3/ 2 3/2 3 (all dorsal and lateral setae long, 67–74), tibia 3 3/2 3/2 3 (all dorsal and lateral setae long, 70–74). Leg II: coxa 0 0/1 0/1 0, trochanter 1 0/1 0/2 1, femur 2 3/1 2/2 2, genu 2 3/2 2/1 2, tibia 2 2/1 2/1 2. Leg III: coxa 0 0/1 0/ 1 0, trochanter 1 0/1 0/1 1, femur 1 2/1 1/0 1, genu 2 2/1 2/1 2 ( Fig. 12 ), tibia: 2 1/1 2/1 2. Leg IV: 0 0/1 0/0 0, trochanter 1 0/2 0/1 1, femur 1 1/0 2/1 1 (al on big spur, Fig. 13 ), genu 2 3/1 3/0 2 (all dorsal and lateral setae long, 69–71), tibia 2 2/1 3/1 2 (all dorsal and lateral setae long, 69–71); all setae fine and needle-like unless otherwise noted. Tarsi I–IV with 18 setae, 3 3/2 3/2 3 + mv, md. All pre-tarsi with membranous ambulacrum, claws very thin.

Insemination structures not seen, apparently unsclerotised.

Male. Dorsal idiosoma. Dorsal shield length 594–628, width 460–480; structure and chaetotaxy as for female.

Ventral idiosoma ( Fig. 8 ). Sternal, genital, endopodal, ventral and anal shields fused to form ornamented composite shield with 13 pairs of setae, three pairs of lyrifissures and one pair of pores. Anal shield fused, unpaired post-anal seta shorter than para-anal setae, cribrum small, anal pores indistinct.

Gnathosoma . Movable digit of chelicera without teeth, spermatodactyl completely fused to movable digit, fixed digit reduced and very short ( Fig. 9 ).

Legs. Chaetotaxy as in female, femur of leg IV with stout spur.

Etymology. The name crinitus (Latin crinitus , hairy) refers to the hypertrichy of the dorsal shield.

Notes. Myrmozercon crinitus differs from all other species in the genus by its very short peritreme, with only a tiny section of peritreme on the anterior side of the stigmata, peritrematal shield very wide and reaching to the anterior level of coxa I, post-stigmatal section very wide, dorsal shield highly hypertrichous, and opisthogaster with an extra irregularly-shaped area of sclerotisation between the genital and anal shields, partly surrounding the genital shield and completely surrounding the anal shield. The male is distinctive in having the anal anal shield fused to the sternal-genital-ventral shield to form a holoventral shield while in other species the anal shield is separate.

Figures

FIGURES 1 – 7. Myrmozercon crinitus Joharchi sp. nov., female. 1. Dorsal shield; 2. Ventral idiosoma; 3. Hypostome; 4. Epistome; 5. Palp tarsal claw; 6. Tritosternum; 7. Chelicera.

FIGURES 8 – 13. Myrmozercon crinitus Joharchi sp. nov., male. 8. Ventral idiosoma; 9. Chelicera; female: 10. femur, genu and tibia I, dorsal aspect; 11. femur, genu and tibia II, dorsal aspect; 12. femur, genu and tibia III, dorsal aspect; 13. femur, genu and tibia IV, dorsal aspect.