Pachylaelaps (Pachylaelaps) pyrenaicus, Masan, Peter, Oezbek, Hasan Hueseyin & Fenďa, Peter, 2016

Masan, Peter, Oezbek, Hasan Hueseyin & Fenďa, Peter, 2016, Two new species of Pachylaelaps Berlese, 1888 from the Iberian Peninsula, with a key to European species (Acari, Gamasida, Pachylaelapidae), ZooKeys 603, pp. 71-95 : 73-78

Taxon classification Animalia Mesostigmata Pachylaelapidae

Pachylaelaps (Pachylaelaps) pyrenaicus sp. n. Figures 1-2, 3-7, 8-12, 13-19

Specimens examined.

Holotype female: North Spain, Central Pyrenees Mts., Cinca Valley, Bielsa Cadaster, Salinas Village (near-by San Marcial Settlement), pine forest ( Pinus spp.) with admixed beech ( Fagus sylvatica ), soil detritus with deep layer of raw humus between rock boulders, altitude 1050 m, 42°35'52,2"N, 00°14'20,0"E, 16 June 2007, coll. P. Fenďa. Paratypes: four females and one male, with the same data as the holotype. The holotype and four paratypes are deposited at the Institute of Zoology, Slovak Academy of Sciences, Bratislava; one female paratype is deposited at the Acarology Laboratory of Erzincan University, Turkey.

Diagnosis.

Slit-like glandular poroids gdZ1 and gdS4 with conspicuously adjacent position. Soft integument with decreased number of 11 pairs of setae in female and eight setal pairs in male. Prestigmatic section of peritreme long, with anterior tip reaching dorsal surface close to setae z1. Dorsal setae long (the longest setae more than 100 μm in length), and seta j5 with tip reaching base of following seta z5. Cheliceral digits unidentate. Male palptibia with two well developed petal-like projections. In female, ventrodistal femur with small spine-like process associated with a seta. Terminal part of male tarsus II with only one spur-like distal seta (pl1). Sperm induction system with tubular components: tubes irregularly formed, folded, curved or with small bumps on distal sections, progressively widened basally; basal part widely abutting to anterior margin of coxa IV.

Description.

Female. Dorsal idiosoma (Figure 1). Dorsal shield 870-915 μm long and 560-610 μm wide, suboval (length/width 1.48-1.63), weakly and unevenly reticulated on surface, and bearing 30 pairs of smooth and needle-shaped dorsal setae. Setae z1 conspicuously shortened, setae J5 strongly reduced in length, vestigial microsetae; other setae relatively longer, subequal and uniform. Length and spacing of some selected dorsal shield setae as follows: j1 53-67 μm, j5 73-83 μm, j5-j5 128-144 μm, j5-z5 72-81 μm, J1-J2 87-111 μm, J2 97-109 μm, J2-J2 216-242 μm, J2-J3 142-172 μm, J3 102-110 μm, J3-J4 118-151 μm, and J4 100-105 μm. Dorsolateral soft integument with four pairs of marginal setae (r6, R5‒R7). Posterolateral poroid structures gdZ1 and gdS4 slit-like, markedly adjacent each other, and placed close to setae Z2 or rarely between setae Z2 and S4.

Ventral idiosoma (Figure 2). Sternal shield 272-280 μm long, proportionally 0.82-0.94 shorter than genitiventral shield, with concave anterior margin and two small projections close to bases of sternal setae st1. Genitiventral shield slightly shorter than wide or subequal in length and width (length 295-335 μm, width 308-337 μm, length/width 0.94-0.99). Anal shield subtriangular, 114-137 μm long and 170-199 μm wide (length/width 0.62-0.73); anus with circum-anal setae situated close to pos terior margin of shield. Peritremes well developed, relatively long, with anterior tip reaching dorsal surface close to setae z1. Peritrematal shields with weak longitudinal sculptural lines, other ventral shields distinctly and evenly reticulated on surface. Metapodal platelets minuscule, free and well separate from peritrematal shields. Ventral soft integument with seven pairs of ventral setae (JV2-JV5, ZV2, ZV4, ZV5). Ventral setae similar to those on dorsal idiosoma.

Sperm induction structures (Figures 3, 13‒16). Tubes of sperm induction system relatively well developed, well sclerotized, broadened basally, and narrowed distally; worm-like distal section irregularly formed, folded, curved or with small bumps; basal section widely abutting to anterior margin of coxa IV.

Gnathosomal structures (Figures 4‒6, 19). Corniculi elongated and horn-like; laciniae densely pilose, slightly longer than corniculi; deutosternum slightly widened medially, with six rows of denticles; subcapitular setae smooth and needle-shaped (Figure 4). Epistome with wide subtriangular base, elongate and narrow central neck and thin apical part crenelated on anterior margin; lateral margins of basal part with delicate denticulation; apical section not expanded or only very slightly expanded anteriorly, terminally truncate and with a row of four to seven prongs (Figure 5). Cheliceral digits relatively elongate and slender (Figures 6, 19), 100-110 μm long; fixed digit of chelicera with terminal hook, small and obtuse subapical denticle, and one larger and flattened distal tooth associated with pilus dentilis; movable digit armed with relatively thin terminal hook and one subdistal tooth.

Legs. Leg setation normal for genus ( Mašán 2007). Femur II with a small spine-like process on ventral distal surface, process associated with a seta. Tarsus II with two spur-like distal setae pl1 and pl2 (Figure 7).

Male. Idiosoma (Figure 8). Dorsal shield 810 μm long and 492 μm wide, suboval (length/width 1.65). Sternal, genitiventral, peritrematal, metapodal, and anal plates are fused together to form an entire holoventral shield bearing nine pairs of setae (excluding three circum-anal setae); the shield irregularly reticulate on surface. Dorsolateral and ventral soft integument with eight pairs of setae (see diagnosis). Dorsal and ventral chaetotaxy and other characters as in female.

Gnathosomal structures (Figures 9, 10, 17, 18). Cheliceral spermatodactyl elongated, ensiform, 162 μm long (about 1.5 times as long as movable digit of chelicera), slightly widened in basal section, progressively tapering toward tip and slightly undulate medially; sperm ductus well defined (Figure 9). Palptibiae normal, not thickened (when compared with other palp segments), each bearing a pair of well-developed petal-like projections on proximal ventral surface (see Figures 17 and 18); outer petal markedly larger than inner one, and longer than cross-sectional radius of palptibia.

Legs. Medial segments of legs II spurred on their distal ventral surface: femur with one robust spur, genu and tibia each with a small knob-like spur, as in Figure 11. Femoral spur broadened basally, produced into obtuse and rounded apex; associated axillar seta pv1 inserted in a small tubercle (Figure 11). Terminal part of tarsus II with only one spur-like distal seta pl1; seta pl2 needle-shaped (Figure 12).

Etymology.

The epithet of this species is derived from the Latin name "Pyrenaei Montes" and alludes to the type locality situated in the Pyrenees Mountains.

Taxonomic notes.

The new species may be distinguished from all other congeners especially by the following combination of characters: (1) in female, tubiform spermathecal structures irregular, with worm-like distal sections having some bends, folds and small bumps, and expanded base widely abutting the anterior margin of coxa IV; (2) female chelicera with flat to truncate subdistal tooth on fixed digit; (3) epistome with narrow central projection bearing a row of four to six denticles; (4) male palptibia with two well developed petal-like projections; (5) terminal part of male tarsus II with only one spur-like distal seta, pl1 (6) cheliceral spermatodactyl simple, ensiform, slightly undulate medially, without irregular convexities or projections on its margin.

Mašán (2007) divided the European members of the subgenus Pachylaelaps into five clusters of species: (1) the bellicosus group ( Pachylaelaps bellicosus and Pachylaelaps multidentatus ), with separate position of slit-like poroid structures gdZ1 and gdS4 on dorsal shield, multidentate cheliceral digits, spermathecal tubiform structures simple, transparent (weakly sclerotized) and relatively longer, and males apparently absent; (2) the denticulatus group ( Pachylaelaps denticulatus only), possessing separate position of slit-like poroid structures gdZ1 and gdS4, three projections on male palptibia, one spur-like distal seta on tarsus II in male, and bidentate cheliceral digits; (3) the ensifer group ( Pachylaelaps armimagnus , Pachylaelaps carpathimagnus , Pachylaelaps ensifer , Pachylaelaps troglophilus and Pachylaelaps sacculimagnus ), characterized by the adjacent position of slit-like poroid structures gdZ1 and gdS4, robust size of idiosoma, spermathecal tubiform structures (if detectable) elongated and weakly sclerotized, and presence of 2‒4 palptibial projections in male and two spur-like distal setae on tarsus II in both adults; (4) the imitans group ( Pachylaelaps imitans , Pachylaelaps insularis , Pachylaelaps resinae and Pachylaelaps terreus ), with adjacent slit-like poroid structures gdZ1 and gdS4 having their openings in a common infundibulum, spermathecal tubiform structures short, conical to cylindrical and strongly sclerotized, two palptibial projections in male, and small lobe-like convexity on ventral margin of cheliceral spermatodactyl; (5) the pectinifer group ( Pachylaelaps littoralis and Pachylaelaps pectinifer ), characterized by the adjacent position of slit-like poroid structures gdZ1 and gdS4, Y-shaped spermathecal tubiform structures, absence of palptibial projections in male, and presence of two spur-like distal setae on tarsus II in both adults.

In this classification scheme, Pachylaelaps (Pachylaelaps) pyrenaicus should be considered as a species with a separate position among the all above mentioned species groups because it possesses a unique combination of main diagnostic characters. Some morphological characters of Pachylaelaps (Pachylaelaps) pyrenaicus are not consistent with those found typically in the individual species groups. The adjacent position of slit-like poroid structures gdZ1 and gdS4 on dorsal shield and unidentate cheliceral digits in the new species are in contradiction with the definition of the bellicosus and denticulatus groups. The male palptibia has two petal-like projections in Pachylaelaps (Pachylaelaps) pyrenaicus , where the pectinifer group species does not have these structures developed. In the robust species of the ensifer group, tarsus II has two spur-like distal setae in adults, but this character is found in the smaller new species only in females. In addition, in Pachylaelaps (Pachylaelaps) pyrenaicus , the tubular structures of sperm induction system have a distinctive form which is not known in the other species of the genus, but is especially different from the members of the imitans group that are characterized by short, conical to cylindrical, and strongly sclerotized spermathecal tubes.