Pachylaelaps (Longipachylaelaps) abludens, Mašán, Peter, 2017

Mašán, Peter, 2017, Four new species of the subgenus Pachylaelaps (Longipachylaelaps) from Italy, with a new identification key to the known species (Acari: Pachylaelapidae), Zootaxa 4236 (1), pp. 95-117 : 96-99

publication ID	https://doi.org/ 10.11646/zootaxa.4236.1.5
publication LSID	lsid:zoobank.org:pub:04D3145C-1C8A-4AE7-968F-7F307E1E732A
DOI	https://doi.org/10.5281/zenodo.5694782
persistent identifier	https://treatment.plazi.org/id/03DD87E1-2E07-C469-A69E-FADEFF5A608D
treatment provided by	Plazi
scientific name	Pachylaelaps (Longipachylaelaps) abludens
status	sp. nov.

Treatment

Pachylaelaps (Longipachylaelaps) abludens View in CoL sp. nov.

( Figs 1 View FIGURES 1 – 2 ¯13, 36, 53)

Specimens examined. Holotype female: North Italy, Bergamo Province , Bergamasque Alps and Prealps, Oltre Il Colle Village, beech forest ( Fagus sylvatica ) with admixed spruce ( Picea abies ), leaf litter and soil detritus, altitude 1,100 m, 13 May 2015, coll. P. Mašán . Paratypes: 8 females and 4 males, same data as holotype.

Diagnosis. In female, tubiform structures of sperm induction system markedly elongated, with subterminal sections hooked and directed forward ( Figs 3 View FIGURES 3 – 9 , 10‒13 View FIGURES 10 – 13 ). Male spermatodactyl notably elongated, more than three times the movable digit, with anterior medial margin finely denticulated ( Figs 5 View FIGURES 3 – 9 , 53 View FIGURES 53 – 56 ). Palptibia with two divergent petal-like projections: antiaxial projection longer, oblong, with rounded distal margin, and small lamellar prominence at its inner base; paraxial projection shorter, subtriangular, and tapered toward obtuse apex ( Figs 8 View FIGURES 3 – 9 , 36 View FIGURES 36 – 39 ).

Description. FEMALE.

Dorsal idiosoma ( Fig. 1 View FIGURES 1 – 2 ). Dorsal shield 785–845 µm long and 470–500 µm wide, elongated and suboval (length/width 1.58–1.75), delicately and evenly reticulated on surface, and bearing 30 pairs of dorsal setae. Dorsal setae uniform, smooth and needle-shaped, mostly subequal in length, relatively shorter and mostly with tips not reaching beyond insertions of following setae; setae z1 shortest. For length and spacing of some selected dorsal shield setae see Table 1 View TABLE 1 . Dorsolateral soft integument with seven pairs of marginal setae (r6, R1, R3‒R7).

Ventral idiosoma ( Fig. 2 View FIGURES 1 – 2 ). Sternal shield 270–284 µm long, nearly as long as genitiventral shield (length of sternal shield/length of genitiventral shield 0.92–1.08). Genitiventral shield almost subequal in length and width (length 268–294 µm, width 265–280 µm, length/width 0.96–1.08). Anal shield subtriangular, 109–129 µm long and 160–187 µm wide (length/width 0.64–0.76); anus with three circum-anal setae situated close to posterior margin of shield. Peritremes normally developed, with anterior tips reaching dorsal surface close to insertions of setae z1. Ventral shields with delicate reticulation on surface. Metapodal platelets minuscule, free on soft integument. Ventral soft integument with nine pairs of ventral setae (JV2–JV5, ZV1–ZV5). Ventral setae similar to those on dorsal idiosoma.

Sperm induction structures ( Figs 3 View FIGURES 3 – 9 , 10‒13 View FIGURES 10 – 13 ). Tubes of sperm induction system well sclerotised and developed, conspicuously elongated; moderately broadened basal portions relatively short, connected to anterior margin of coxae IV, and less sclerotised than other tubular portions; medial portions regularly curved and directed posteriorly; distal portions closely adjacent each other, with short subterminal sections abruptly hooked and directed forward; tips of tubes regularly rounded.

Gnathosomal structures ( Figs 4, 6 View FIGURES 3 – 9 ). Corniculi elongated and horn-like; laciniae densely pilose, as long as corniculi; deutosternum with six rows of denticles; subcapitular setae smooth and needle-shaped. Epistome with subtriangular and regularly narrowed base, narrow central neck and widened apical part densely crenulate anteriorly; basal part with denticulate lateral margins ( Fig. 4 View FIGURES 3 – 9 ). Fixed digit of chelicera with bifid terminal hook, one large distal tooth associated with pilus dentilis, and one additional distal denticle on lateral ridge; pilus dentilis well developed, curved and directed backward; movable digit of chelicera unidentate, with simple hook and one distal tooth ( Fig. 6 View FIGURES 3 – 9 ).

Legs. Leg setation normal for genus (Mašán, 2007). Tarsus II with two spur-like distal setae, pl1 and pl2 ( Fig. 9 View FIGURES 3 – 9 ).

MALE. Dorsal idiosoma. Dorsal shield 690‒770 µm long and 400‒445 µm wide, elongated and suboval (length/width 1.64‒1.78).

Ventral idiosoma. Sternal, genitiventral, peritrematal, metapodal and anal plates fused to form an entire holoventral shield bearing nine pairs of setae (st1‒st5, JV1‒JV3, ZV2), not including three circum-anal setae close to anus; shield with reticulate sculpture on surface. Dorsolateral and ventral soft integument with 13 pairs of setae (r6, R1, R3‒R7, JV4, JV5, Zv1, ZV3‒ZV5). Dorsal and ventral chaetotaxy, and other characters as in female.

Gnathosomal structures ( Figs 5, 8 View FIGURES 3 – 9 , 36 View FIGURES 36 – 39 , 53 View FIGURES 53 – 56 ). Cheliceral spermatodactyl elongate, 205‒225 µm in length, 3.2‒3.6 times as long as movable digit, expanded and foliate proximally, conspicuously narrowed distally, anterior medial margin finely denticulated ( Figs 5 View FIGURES 3 – 9 , 53 View FIGURES 53 – 56 ). Palptibiae moderately thickened medially compared with other palp segments, each bearing a pair of petal-like projections on proximal ventral surface, as in Figs 8 View FIGURES 3 – 9 and 36 View FIGURES 36 – 39 ; projections relatively large, with divergent adjacent margins: antiaxial projection longer, with narrower base, almost parallel proximal margins, distal margin irregularly rounded, apex asymmetrical in relation to longitudinal axis, and small lamellar prominence at its inner base; paraxial projection shorter, subtriangular, widened basally and tapered toward obtuse apex. Palpfemur with distinct papular tubercle on anterolateral basal surface.

Legs. Medial segments of legs II spurred on their distal ventral surface: femur with one robust spur, genu and tibia each with a peg-like spur, as in Fig. 7 View FIGURES 3 – 9 . Femoral spur broadened in basal part, produced into narrowly rounded apex, with two small tubercles on axillary side ( Fig. 7 View FIGURES 3 – 9 ). Terminal part of tarsus II with only one spur-like distal seta, pl1.

Etymology. The specific name of the new species is derived from the Latin word " ablūdō " (be unlike), and it alludes to the fact that the species is easily discernible and markedly differing from its congeneric species.

Taxonomic notes. The new species may be easily distinguished from all other congeners by the subapically hooked tubes of the sperm access system in females, and the unusually elongated spermatodactyl in males. Although such elongate spermatodactyl is also found in Pachylaelaps (Longipachylaelaps) pulsator , P. (L.) longicrinitus and P. (L.) silviae , no other known species of the genus Pachylaelaps has a denticulate anteromedial margin of the spermatodactyl other than P. (L.) abludens sp. nov., and one further new species described below. For a detailed comparison of P. (L.) abludens sp. nov. and other known Pachylaelaps (Longipachylaelaps) species see Table 2.