Pachyseius masani, Özbek, Hasan Hüseyin & Halliday, Bruce, 2014

Özbek, Hasan Hüseyin & Halliday, Bruce, 2014, Two new species of Pachyseius Berlese (Acari: Pachylaelapidae) from Turkey, with a key to the world species, Zootaxa 3841 (1), pp. 107-116 : 110-113

Pachyseius masani sp. nov.

Diagnosis. Ventri-anal shield bearing three pairs of pre-anal setae; presternal area weakly sclerotised with web like pattern; metasternal shields free in soft skin; posterior ends of peritrematal shields tapering, extending beyond coxae IV, contiguous with exopodal shield but not fused with them; metapodal shields well separated from anterolateral margins of ventri-anal shield; opisthogastric skin between peritrematal shields and anterolateral margins of ventri-anal shield with one pair of larger oval platelets and two pairs of smaller circular platelets, and five pairs of setae in opisthogastric skin lateral to ventri-anal shield.

Specimens examined. Holotype female, Gümüşhane Province, between Şiran and Alucra, 40° 09' 96'' N, 39° 00' 18'' E, alt. 1305 m, 23 April 2012, from litter under Salix sp. Paratypes: three females with same data as holotype; two females, Gümüşhane, between Şiran and Alucra, 40° 15' 52 N, 38° 57' 90 E, alt. 1570 m, 23 April 2012, from dung; one female, Gümüşhane, Köse, 40° 18' 57'' N, 39° 38' 12'' E, alt. 1880 m, 19 May 2012, from litter under Pinus sp.

Description. Female ( Figures 7–13 , 16–17 )

Dorsum ( Fig. 7 ) (n= 7). Dorsal shield 580 (560–600) long, 320 (310–320) wide at widest point, oblong (length/ width, 1.80–1.96), ornamented with reticulate pattern and punctate, carrying 30 pairs of short setae, all smooth and pointed; a pair of lyrifissures between j1 and z1; a pair of well sclerotised, wide open cavity-like gland pores gdj3 present between seta z1 and z2; and five pairs of conspicuous postero-lateral pores. Anterior ends of peritremes reaching or extending beyond level of gdj3. Setae z1 shortest, 8–12; j1, j2 short, 14–18; j5, j6, z 5 22–26; S1–S5 longest, 21–38; J 5 31–36.

Venter ( Fig. 8 ). Presternal area weakly sclerotised with web like ornamentation. Sternal shield ( Fig. 16 ) 120 (120–130) long, 90 (90–95) wide at the level of coxae II, ornamented with web-like pattern and carrying three pairs of smooth pointed setae. Length of setae St 1 26–29, St 2 27–31, St 3 27–31. Metasternal shields small, oval and free in soft skin, each bearing a metasternal seta (26–28) and a poroid. Epigynal shield 110 (100–110) long, 80 (80–90) wide at widest point, ornamented with punctate lines; a row of elongate platelets along its posterior margin; genital pores situated outside the shield; genital setae length 23–28. Ventri-anal shield ( Fig. 17 ) longer than wide, 220 (220–240) long, 160 (150–160) wide at the widest point (length/width 1.43–1.57), reticulated with punctate lines, and bearing three pairs of sub-equal pre-anal setae, a pair of para-anal setae and a longer postanal seta. Posterior ends of peritrematal shields tapering, extending beyond level of coxae IV, not fused with exopodal shield; with a pair of large post-stigmatal pores and a pair of smaller pores. Opisthogastric skin between peritrematal shields and anterolateral margins of ventri-anal shield with one pair of large oval platelets and two pairs of small circular platelets. Metapodal shields elongated (50 long) and well separated from anterolateral margins of ventri-anal shield (25–50). Opisthosomal soft skin bearing one pair of setae near the stigmata; opisthogastric skin surrounding ventrianal shield bearing five pairs of setae (length of setae in soft skin 17–43).

Gnathosoma . Hypostome with four pairs of setae, all smooth and needle-like, h3 longest, h2 shortest; deutosternum with five transverse rows of denticles, six to eight denticles per row. Corniculi horn-like ( Fig. 9 ). Palp with 3-tined apotele. Anterior margin of epistome truncate and denticulate, details of denticulation variable ( Fig. 10 ). Cheliceral digits slender, movable digit with two medial teeth and a terminal hook, arthrodial brush onethird length of movable digit, fixed digit with a single medial tooth, bidentate terminal hook, and fine pilus dentilis ( Fig. 11 ).

Spermathecal apparatus ( Fig. 12 ). Spermathecal tubes long and fine, associated with coxae III.

Legs. Chaetotaxy: Leg I. Coxa 0 0/2 0, trochanter 1 1/3 1, femur 2 5/4 2, genu 2 5/3 2, tibia 2 5/3 2. Leg II. Coxa 0 0/2 0, trochanter 1 0/3 1, genu 2 5/2 2, tibia 2 4/2 2, tarsus 3 7/5 3. Leg III. Coxa 0 0/2 0, trochanter 1 0/3 1, femur 1 3/1 1, genu 2 4/1 1, tibia 1 3/2 1, tarsus 3 7/5 2. Leg IV. Coxa 0 0/1 0, trochanter 1 0/3 1, femur 1 3/1 1, genu 2 4/1 1, tibia 1 3/2 1, tarsus 3 6/5 2. Tarsus II with one large spur like seta ( Fig. 13 ).

Etymology. The species is named for acarologist Dr. Peter Mašán of the Institute of Zoology, Slovak Academy of Sciences, Bratislava.

Notes. Pachyseius masani is distinguished from other species of the genus by the ventri-anal shield with three pairs of pre-anal setae, presternal area weakly sclerotised, metasternal shields free, posterior section of peritrematal shield not fused with the exopodal shield, and only five pairs of setae in the lateral opisthogastric soft skin. It is very similar to P. slavicus Mašán, 2007 but differs from it in having different ornamentation of the ventri-anal and sternal shields, shorter dorsal shield setae j3 and z2, and the anterior ends of the peritremes extending further beyond gdj3.

Pachyseius masani is remarkable in having reduced chaetotaxy on tarsi III and IV. It lacks postero-lateral seta pl3 on the basitarsus of legs III and IV, and it also lacks seta ad2 on tarsus IV. This is true on both sides of all seven of the specimens we examined. Several species in the P. humeralis group lack ad2 on tarsus IV (Mašán, 2007 and personal observations), and the absence of pl 3 in P. masani appears to represent a further loss of setae in a member of this group. Unfortunately it is not possible to use this character as a diagnostic tool in other species without examining type specimens, because the leg chaetotaxy is rarely described in enough detail.

Figures

FIGURES 7 – 13. Pachyseius masani sp. nov., female. 7. dorsal shield; 8. ventral idiosoma; 9. gnathosoma; 10. epistome; 11. chelicera; 12. sperm access system; 13. leg II (tibia-tarsus). Scale bars: 200 µm for 7,8 and 12, 100 µm for 9 – 11 and 13.

FIGURES 14 – 17. Pachyseius spp., females. 14. Pachyseius siranensis sp. nov., sternal shield; 15. Pachyseius siranensis sp. nov., ventri-anal shield; 16. Pachyseius masani sp. nov., sternal shield; 17. Pachyseius masani sp. nov., ventri-anal shield.