Pachylaelaps ( Pachylaelaps ) evansi Costa, 1971

Pachylaelaps ( Pachylaelaps) evansi Costa, 1971 View in CoL

Pachylaelaps evansi Costa, 1971: 255 View in CoL .

Pachylaelaps ( Pachylaelaps) evansi View in CoL — Mašán & Halliday, 2014: 35 View Cited Treatment ; Özbek & Mašán, 2018; 490.

( Figs 18–23 View FIGURES 18−23 )

Diagnosis (Adults)

Dorsal setae z1 longer than j1, J5 microsetae; one pair of posterolateral slit-like gland pores gdS4 present on shield, gdZ1 not modified, subcircular; anterior ends of peritremes reaching dorsal surface and between setae z1 and z2. In females, genitiventral and anal shields extremely close to each other, setae Jv2 mostly located at the posterolateral margins of genitiventral shield and soft integument with 14 pairs of setae; tubes of spermathecal apparatus connected to coxae IV, clearly visible, short and tubular. In males, the spermatodactylus more than twice as long as movable digit, tapering towards distal part and basally with a well-developed triangular process basally; palptibiae each with distinct, flat and distally triangular processes.

Material examined. 8♀♀ and 2♂♂ from litter of Juniperus sp. , 39°12‘N 38°34‘E, 950 m a.s.l., 08 March 2023; 1♀ from litter of Quercus sp. , 39°12‘N 38°34‘E, 950 m a.s.l., 08 March 2013; 1♀ from moss, 39°12‘N 38°36‘E, 1031 m a.s.l., 08 March 2023; 1♀ and 1♂ from moss, 39°12’N 38°36’E, 1031 m a.s.l., 08 March 2023 — the Karasu Valley ( Kemaliye) .

Description. Female.

Dorsum. Dorsal shield 580–640 long and 300–340 wide, suboval and elongate (length/width 1.76–1.92), finely and evenly reticulate over entire surface, with 30 pairs of smooth and pointed setae. Setae z1 longer than j1 ( j1 18–22, z1 28–32); length of setae j2, j4, j5, j6, z2, r2, r3, r5, s2, s6, S1, S3 45–60, j3, z4–6, s4–5, J1–4, Z1–3, S4–5 60–75, J5 micro-setae (4–6). A pair of posterolateral poroid structures ( gdS4) with slit-like openings present between setae S4 and S5, gdZ1 not modified, normal subcircular shape.

Venter . Sternal shield 190–210 long, 110–130 wide at level of coxae II, its surface between st1 and st4 decorated with reticulate polygonal patterns. Seta st1 (55–66) longest, st3 shortest (30–40), st2 and st4 of equal length (50– 60). Genitiventral shield distinctly concave posteriorly, longer than wide (wider than long only in two specimens) (length 197–232, width 185–215, length/width 0.93–1.12), ornamented with reticulate lines, with three pairs of setae ( st5 45–52, Jv1 50–60, Jv2), and extremely close to anal shield (contiguous), and setae Jv2 on posterior edges of genitiventral shield ( Fig. 18 View FIGURES 18−23 ). Anal shield subtriangular, distinctly convex anteriorly 80–96 long and 122–142 wide (length/width 0.61–0.75); anus with three circum-anal setae near posterior margin of shield, ornamented with reticulate lines. Peritremes normally developed, relatively long, anterior ends reaching dorsal surface and between setae z1 and z2. Metapodal platelets large, free, separated from peritrematal shields. Lateral soft integument with seven pairs of marginal setae ( r6, R1 , R3 – R7 ). Ventral soft integument with seven pairs of opisthogastric setae ( Jv3–Jv5, Zv2–Zv5) .

Spermathecal apparatus. Tubes associated with coxae IV, clearly visible, short and tubular ( Fig. 19 View FIGURES 18−23 ).

Gnathosomal structures. Corniculi elongate and lanceolate. Deutosternal groove with six rows of denticles. Epistome with straight denticulate lateral margins and central projection with strong apical denticle. Chelicera well developed with strong subdistal teeth; movable digit about 57–62 long, with one large subdistal tooth and terminal hook; fixed digit about 50–53 long (to dorsal seta), with two large subdistal teeth, one tridentate terminal hook, and one pilus dentilis ( Fig. 20 View FIGURES 18−23 ). Arthrodial brush short.

Legs. Genu I with 12 setae ( pd3 absent), other leg setation normal for the genus ( Mašán, 2007). Tarsus II with two spur-like distal setae pl1 and pl2.

Description. Male.

Dorsum. Dorsal shield 490–530 long 290–305 wide at the level widest point (length/width 1.37–1.52), suboval shaped, setae J4 60–65, J5 microsetae. Ornamentation and dorsal chaetotaxy as for female.

Venter . Holoventral shield 415–420 long, 265–280 wide at the level coxae II, ornamented with reticulate pattern and bearing nine pairs of setae (plus three circum-anal setae around anus). Dorso-lateral and ophisthogastric soft integument with 12 pairs of setae.

Gnathosomal structures. Moveable digit of chelicera 46 long, with a subdistal tooth and terminal hook, spermatodactyl 110–115 long, more than twice as long (2.45) as movable digit, narrowing towards the distal part and basally with a well-developed triangular process ( Fig. 21 View FIGURES 18−23 ). Fixed digit with a subdistal tooth, bidentate terminal hook and a thin pilus dentilis. Palptibiae each with distinct, distally triangular, flat projections ( Fig. 22 View FIGURES 18−23 ).

Leg II ( Fig. 23 View FIGURES 18−23 ). Femur with large, finger-shaped, distally tapering and apically truncated, spur-like process connected to a seta on a large tubercle; genu and tibia each with a small process and connected to a seta; tarsus with a large spur-like seta pl1.

Remarks: Pachylaelaps ( Pachylaelaps) evansi was first described by Costa (1971) from Israel based on both female and male specimens, accompanied by high-quality hand drawings and detailed morphological descriptions. Later, Özbek and Mašán (2018) provided additional morphological insights based on two female specimens from Tunceli province in Türkiye, reporting the presence of 12 setae on genu I (with pd3 absent) and fifteen pairs of setae on the soft integument (seven pairs of marginal setae and eight pairs of opisthogastric setae). Furthermore, Costa (1971) did not mention the tubes of the spermathecal apparatus in his original description, and Özbek & Mašán (2018) hypothesized that these structures are likely unsclerotized, rudimentary, or absent.

In the present study, ten females and three males specimens of P. evansi were collected from the valley. These specimens were examined in detail, photographed, and measured, yielding several new and significant findings for the species. These findings are as follows: (1) the tubes of the spermathecal apparatus are clearly visible, associated with the posterior margin of coxae IV, and appear short and tubular; (2) setae Jv 2 are predominantly positioned on the posterior margin of the genitiventral shield, although in one of the newly collected specimens and two previously collected specimens from Tunceli province, they are located on the soft integument; (3) setae z1 are distinctly longer than j1; (4) genu I and tibia I of the males exhibit distally narrowed processes; and (5) more detailed morphometric data and differential interference contrast ( DIC) images are provided to further elucidate the species‘ morphological characteristics .