Pachyseius destitutus, 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 : 99-101

Pachyseius destitutus sp. nov.

( Figs 1–6 , 19–21 )

Diagnosis. Dorsal shield bearing 29 pairs of long and pointed setae, z1 absent; anterior margin of ventri-anal shield conspicuously concave, with three pairs of pre-anal setae, post-anal seta longer than other ventri-anal setae; anterolateral margins of ventrianal shield closely adjacent to relatively long and narrow metapodal shield; presternal shields absent; peritrematal shields fused with exopodal shields, their posterior ends reaching beyond coxae IV; soft integument between peritrematal shields and anterolateral margins of ventri-anal shield with one pair of small oval platelets; epigynal shield reduced in size, relatively small, posterior margin with a transverse row of four elongate platelets and a pair of small oval platelets; lateral and opisthogastric soft integument with 11 pairs of setae.

Specimens examined. Holotype female, Trabzon Province, Demirkapı Village, 40°34'23'' N, 40°24'06'' E, alt. 1740 m, 17 June 2014, litter under Pinus sp. Paratypes: 16 females, same data as holotype.

Female. Dorsum ( Fig. 1 ). Dorsal shield 485–535 long, 275–300 wide at widest point, oblong (length/width, 1.70–1.78), ornamented with net-like pattern, and bearing 29 pairs of mostly long and pointed needle-like setae, setae z1 absent ( Fig. 19 ); setae j1 shortest, 10–12; j2 34–50; j3, s4, s5, and Z1 70–75; z6 60–65; J 5 22–28, other dorsal setae 35–60; a pair of lyrifissures near bases of j2; slit-like gland pores gdj3 present between seta j2 and s2; anterior ends of peritremes extending forward beyond level of gdj3.

Venter ( Fig. 2 ). Pre-sternal shields absent. Sternal shield 135–145 long, 65–75 wide at level of coxae II; central region ornamented with punctate polygonal lines; carrying three pairs of pointed needle-like setae and two pairs of lyrifissures, edges of shield strongly sclerotised. Length of sternal setae st 1-3 20–28. Metasternal shields small, each bearing a metasternal seta (18–22) and a poroid. Epigynal shield 58–65 long, 70–85 wide at widest point, with punctate ornamentation, and a row of four elongate platelets and a pair of small oval platelets along its posterior margin; genital pores situated outside postero-lateral margins of shield, genital setae length 18–22. Ventri-anal shield with a concave anterior margin ( Fig. 20 ) 182–210 long, 182–200 wide at widest point (length/width, 0.95– 1.07), with polygonal ornamentation, bearing three pairs of pointed pre-anal setae (Jv1 and Jv2, 20–25; Jv3 shorter, 14–16), a pair of longer para-anal setae (28–30), and a long postanal seta (30–38). Peritrematal shields fused with exopodal shields, with four pairs of small post-stigmatal pores, their posterior ends rounded, enclosing posterior margins of coxae IV and extending medially almost to genital setae. Opisthogastric soft integument between peritrematal shields and anterolateral margins of ventri-anal shield with one pair of oval platelets. Metapodal shields elongated (60–62 long) and very close to anterolateral margins of ventri-anal shield. Lateral and opisthogastric soft integument bearing 11 pairs of setae (15–22).

Gnathosoma ( Fig. 3 ). Corniculi short and horn-like; hypostomal seta h3 longest (45–52), h2 shortest (10–14), and h 1 23–27 long; pc 15–19 long; deutosternal groove with five rows of denticles and two smooth transverse lines ( Fig. 21 ). Palp with 3-tined apotele. Anterior and lateral margins of epistome denticulate ( Fig. 4 ). Cheliceral digits slender, movable digit about 45 long, with two subdistal teeth and an terminal hook, fixed digit about 40 long (to dorsal seta), medially edentate, terminally with bidentate hook; pilus dentilis minute; arthrodial brush short ( Fig. 5 ).

Spermathecal apparatus . Spermathecal tubes not visible in the available specimens.

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 one large spur-like seta ( Fig. 6 ).

Etymology. The name destitutus , lacking, refers to the loss of dorsal shield seta z 1 in this species.

Notes. The new species may be easily distinguished from the other congeners by the dorsal shield with 29 pairs of setae, z1 absent, and the peritrematal shields fused with all the exopodal shields. The only other species of Pachyseius that lacks seta z1 is P. cavernicola (we have examined the holotype of P. cavernicola , and confirm that z1 setae are absent), but these two species are clearly distinguished by the number of pre-anal setae (two pairs in P. cavernicola , three in P. destitutus ), the different length and form of the dorsal shield setae (spatulate in P. cavernicola , pointed in P. destitutus ), the shape of the epistome (broadly arched in P. cavernicola , narrower in P. destitutus ), and the number of spur-like seta on tarsus II (two in P. cavernicola , one in P. destitutus ). The collection of 17 females and no males, and the apparent absence of insemination structures in the females, suggests that P. destitutus may be thelytokous, but that is unconfirmed.

Figures

FIGURES 1 – 2. Pachyseius destitutus sp. nov., female. 1. Dorsal shield; 2. Ventral idiosoma.

FIGURES 3 – 6. Pachyseius destitutus sp. nov., female. 3. Ventral gnathosoma; 4. Epistome; 5. Chelicera; 6. Tarsus 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.