Pachyseius quadrigeminus, Özbek, Hasan Hüseyin & Halliday, Bruce, 2015

Özbek, Hasan Hüseyin & Halliday, Bruce, 2015, Two new species of Pachyseius Berlese (Acari: Pachylaelapidae) from Turkey, with a key to the world species, Zootaxa 3957 (1), pp. 98-108 : 101-104

Pachyseius quadrigeminus sp. nov.

( Figs 7–18 ; 22)

Diagnosis. In female, peritrematal shields fused with exopodal shields; ventri-anal shield bearing four pairs of preanal setae; pre-sternal shields absent; area between peritrematal shields and anterolateral margins of ventri-anal shield with two pairs of oval platelets, lateral and opisthogastric soft integument with seven pairs of setae. In male, holoventral shield present, opisthogastric region of shield with four pairs of ventral setae; spermatodactyl 90–110 long, and distally narrowed. Tarsus II with two spur-like setae.

Specimens examined. Holotype female, Gümüşhane Province, Çıkrıkdüzü Wold, 40°39'58'' N, 38°59'50'' E, alt. 1990 m, 12 October 2013, litter under Abies sp. Paratypes: 2 females, same data as holotype; 1 female and 6 males; Gümüşhane Province, Kürtün Town, Örümcek Forest, 40°39'48'' N, 39°01'46'' E, alt. 1455 m, 1 June 2009, litter under Picea sp.; 1 female, Gümüşhane Province, Kürtün Town, Kızılali Wold, 40°48'17'' N, 39°04'04'' E, alt. 1555 m, 13 October 2013, litter under Rubus sp.

Female. Dorsum ( Fig. 7 ). Dorsal shield 600–676 long, 310–368 wide at widest point, oblong (length/width, 1.71–1.94), ornamented with reticulate pattern, carrying 30 pairs of setae, all smooth and pointed; setae z1 shortest (8–10); j 1 15–20; z2, s2, r3 and J5 distinctly longer (30–40), other dorsal setae 20–30 long; a pair of lyrifissures present between j2 and z1; a pair of slit-like gland pores gdj3 present between seta z1 and z2. Anterior ends of peritremes reaching or extending beyond level of z1.

Venter ( Fig. 8 ). Pre-sternal shields absent. Sternal shield 140–152 long, 80–90 wide at level of coxae II, central region ornamented with punctate polygonal lines, carrying three pairs of smooth pointed setae and two pairs of lyrifissures, edges of shield strongly sclerotised. Length of setae st 1–3 25–36. Metasternal shields very small, each bearing a metasternal seta (20–25) and a poroid. Epigynal shield 85–95 long, 100–110 wide at widest point, with punctate ornamentation; one pair of elongate platelets on its posterior margin; genital pores situated outside shield; genital setae length 23–27. Ventri-anal shield ( Fig. 22 ) longer than wide, 248–270 long, 208–233 wide at widest point (length/width 1.10–1.21), reticulated with punctate lines, and bearing four pairs of sub-equal pre-anal setae (20–30), a pair of longer para-anal setae (30–35) and a long post-anal seta (40–46). Peritrematal shields fused with exopodal shields, with two pairs of small post-stigmatal pores and truncated posterior margin, their posterior ends rounded, enclosing posterior margins of coxae IV and extending beyond level of genital setae. Soft integument between peritrematal shields and anterolateral margins of ventri-anal shield with two pairs of oval platelets. Metapodal shields elongate (60–65 long) and not well separated from anterolateral margins of ventri-anal shield. Lateral and opisthogastric soft integument bearing seven pairs of setae (15–25).

Gnathosoma ( Fig. 9 ). Subcapitulum with four pairs of setae, all smooth and needle-like, h3 longest (48–52), h2 shortest (12–15), setae pc 18–22 long, h 1 26–30 long. Deutosternum wide, with five long transverse rows of denticles. Corniculi horn-like. Palp with 3-tined apotele. Anterior and lateral margins of tongue-shaped epistome denticulate ( Fig. 10 ). Cheliceral digits slender, movable digit 54–58 long, with two subdistal teeth and a terminal hook; arthrodial brush short; fixed digit 40–45 long (to dorsal seta), with a single submedial tooth and bidentate terminal hook; pilus dentilis not seen ( Fig. 11 ).

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

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, femur 2 5/3 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 3. 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 7/5 3. Tarsus II with two large spur like setae ( Fig. 13 ). Male. Dorsum. Dorsal shield 510–558 long, 313–342 wide at widest point, oblong (length/width, 1.59–1.66), ornamented with reticulate pattern. Other features as in female.

Venter ( Fig. 14 ). Holoventral shield present, 423–464 long, 80–85 wide at level of coxae II; sternal region with punctate-reticulate ornamentation, and bearing five pairs of needle-like setae and three pairs of lyrifissures; opisthogastric portion of shield ornamented with punctate polygonal lines, with four pairs of setae (15–28); anal portion with a pair of para-anal setae (25–30) and longer post-anal seta (35–40). Peritrematal shields connected to holoventral shield. Other features as in female.

Gnathosoma. Epistome triangular, with denticulate anterior margin ( Fig. 15 ). Movable digit of chelicera 60–65 long, with a larger subterminal tooth and bidentate terminal hook; spermatodactyl directed posteriorly, 90–110 long, and distally narrowed; fixed digit about 46 long (to dorsal seta), slender, edentate and with a minute pilus dentilis; arthrodial brush short ( Fig. 16 ).

Legs. Femur II with well-developed ventral spur, genu II and tibia II each with smaller ventral spur ( Fig. 17 ); tarsus II with two spur-like dorsal setae ( Fig. 18 ).

Etymology. The name quadrigeminus , four pairs, refers to the presence of four pairs of setae on the ventri-anal shield, in addition to the circumanal setae.

Notes. The new species is easily distinguishable from the other congeners by the ventri-anal shield with four pairs of pre-anal setae, peritrematal shields fused with exopodal shields, and the male with a holoventral shield.

The ventri-anal shield in Pachyseius usually has two or three pairs of pre-anal setae. Only P. sinicus has four pairs, but according to Özbek & Halliday (2014), two of these pairs are on the extreme lateral edges of the shield, where their positions may show intra-specific or artificial variation. All of our females of P. quadrigeminus sp. nov. carry four pairs of setae, and they are well inside the lateral edges of the shield.

Figures

FIGURES 7 – 8. Pachyseius quadrigeminus sp. nov., female. 7. Dorsal shield; 8. Ventral idiosoma.

FIGURES 9 – 13. Pachyseius quadrigeminus sp. nov., female. 9. Ventral gnathosoma; 10. Epistome; 11. Chelicera; 12. Sperm access system; 13. Tarsus II.

FIGURES 14 – 18. Pachyseius quadrigeminus sp. nov., male. 14. Ventral idiosoma; 15. Epistome; 16. Chelicera; 17. Ventral spurs on leg II (fem. = femur, gen. = genu, tib. = tibia); 18. Telotarsus II.

FIGURES 19 – 22. Pachyseius spp., females. 19. P. destitutus sp. nov., anterior region of dorsal idiosoma; 20. P. destitutus sp. nov., ventri-anal shield; 21. P. destitutus sp. nov., ventral gnathosoma; 22. P. quadrigeminus sp. nov., ventri-anal shield. Not scaled.