Research Article |
Corresponding author: Peter Mašán ( uzaepema@savba.sk ) Academic editor: Farid Faraji
© 2016 Peter Mašán, Hasan Hüseyin Özbek, Peter Fenďa.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Mašán P, Özbek HH, Fenďa P (2016) Two new species of Pachylaelaps Berlese, 1888 from the Iberian Peninsula, with a key to European species (Acari, Gamasida, Pachylaelapidae). ZooKeys 603: 71-95. https://doi.org/10.3897/zookeys.603.9038
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Pachylaelaps (Pachylaelaps) pyrenaicussp. n. and Pachylaelaps (Longipachylaelaps) brevipilissp. n. (Acari, Pachylaelapidae) are described and illustrated based on specimens from litter and soil detritus of forest habitats in Spain (Pyrenees Mts) and Portugal (Serra da Labruja Mts), respectively. An identification key to European species of the genus Pachylaelaps Berlese, 1888 is provided.
Description, Europe, identification key, Mesostigmata , morphology, soil mites, systematics
Pachylaelapid mites (Acari, Mesostigmata, Gamasida, Eviphidoidea) represent a cosmopolitan group of free-living mites with extraordinarily wide ecological and behavioural diversity (including more than 230 known species and 16 genera worldwide). They constitute an important component of the fauna in all soil microhabitats of the temperate zone of the northern hemisphere. They colonise various soil substrates, especially leaf litter and decomposing organic detritus (
The genus Pachylaelaps Berlese, 1888 belongs to the largest pachylaelapid genera and currently includes 56 valid species. Its continental diversity, based on the original type specimens and excluding those which have been incorrectly classified in the genus at some time, covers Europe (38 spp.), Asia (13 spp.), Africa (3 spp.), South America (1 sp.) and Australia (1 sp.) (
When compared with other taxa of edaphic mesostigmatic mites, Pachylaelaps are relatively little-known in Europe. The almost identical appearance of individual species, which causes difficulties in species identification, may also explain the small number of papers exclusively devoted to the European species of the genus Pachylaelaps (
The main aim of this paper is to describe two new soil-inhabiting species of the little known genus Pachylaelaps, compare them with other morphologically similar congeneric species, and provide an updated identification key to the European species of this genus.
Collected mites were extracted from the litter and soil detritus by means of a modified Berlese-Tullgren funnel equipped with a 40 Watt bulb, and preserved in ethyl alcohol. Before identification, the mites were mounted onto permanent microscope slides, using Swan’s chloral hydrate mounting medium. Illustrations were made by H. H. Özbek using a normal optical microscope equipped with a drawing tube. A Leica DM 1000 light microscope equipped with a stage-calibrated ocular micrometer and a Leica EC3 digital camera was used by P. Mašán to obtain measurements and photos. Measurements were made from slide-mounted specimens. Some multiple images were combined using the CombineZP software program (
Pachylaelaps
Berlese, 1888: 196. Type species Gamasus pectinifer G. Canestrini, 1881, by subsequent designation (
Pachylaelaps can be reliably diagnosed by the following combination of characters: (1) dorsal shield oblong, suboval, and bearing 30 pairs of mostly subequal setae; (2) dorsocentral setae J2 in normal posterolateral position to setae J1; (3) sternal and genitoventral shield with four and two pairs of setae, respectively; (4) female tarsus II with two spur-like distal setae, pl1 and pl2; (5) sperm induction system of female associated with coxae IV; (6) tibial projections on male palp developed (except for species of Pachylaelaps pectinifer group); (7) genu I with 13 setae.
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.
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.
Female. Dorsal idiosoma (Figure
Ventral idiosoma (Figure
Sperm induction structures (Figures
Gnathosomal structures (Figures
Legs. Leg setation normal for genus (
Male. Idiosoma (Figure
Gnathosomal structures (Figures
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
The epithet of this species is derived from the Latin name “Pyrenaei Montes” and alludes to the type locality situated in the Pyrenees Mountains.
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.
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 P. (P.) 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 P. (P.) 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 P. (P.) 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.
Holotype female: North Portugal, Serra da Labruja Mts., San Bento da Porta Aberta Village, Viana do Castelo Cadaster, non-native eucalyptus forest (Eucalyptus globulus), humid leaf litter and soil detritus, altitude 260 m, 41°56'02,3"N, 08°37'49,9"W, 10 May 2008, coll. P. Fenďa. Paratypes: 45 females and 14 males, with the same data as in holotype. The holotype and paratypes are deposited at the Institute of Zoology, Slovak Academy of Sciences, Bratislava; six paratypes (three females and three males) are deposited at the Acarology Laboratory of Erzincan University, Turkey.
Soft integument with decreased number of 13 pairs of setae in female and ten setal pairs in male. Dorsal setae J5 well developed, slightly longer than setae J4. Prestigmatic section of peritreme long, with anterior tip reaching dorsal surface close to setae z1. Dorsal setae relatively short (longest setae not exceeding 35 μm in length), with their tips not reaching bases of following setae. Cheliceral digits unidentate; pilus dentilis conspicuously enlarged (in female) or vestigial (in male). Male palptibia with two petal-like projections, shorter than cross-sectional radius of palptibia. Terminal part of male tarsus II with only one spur-like distal seta (pl1). Sperm induction system with tubular components: tubes relatively shorter, with club-shaped apical section, straight or variously curved; basal part not markedly expanded, thin, associated with inner middle surface of coxa IV.
Female. Dorsal idiosoma (Figure
Ventral idiosoma (Figure
Sperm induction structures (Figures
Gnathosomal structures (Figures
Legs. Leg setation normal for genus (Mašán, 2007). Tarsus II with two spur-like distal setae, pl1 and pl2 (Figure
Male. Idiosoma (Figure
Gnathosomal structures (Figures
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 Figure
The specific name of the new species is derived from the Latin words “brevis” (short) and “pilum” (hair), and it alludes to the fact that the species has the shortest idiosomal setae among its congeners.
The main diagnostic character states for Pachylaelaps (Longipachylaelaps) brevipilis are the presence of shorter idiosomal setae (e.g., j5 < j5–z5, J1 ≈ ½ x J1–J2), the relative length of dorsal setae J4 and J5 (setae J5 negligibly longer than J4, about 1.04–1.14 times as long as J4), the existence of sexual dimorphism in the pilus dentilis (markedly enlarged and spiniform in female, minute and slender in male), the form of the tubular structures of the sperm induction system (tubes shorter, with club-like terminal part), the form and length of the cheliceral spermatodactyl (sword-like, less than twice as long as movable digit), and the length of the dorsal shield (small species, with dorsal shield 470–510 μm long in males, and 510–565 μm long in females).
The presence of relatively short dorsal setae (at least in a central row), along with subequal setae J4 and J5, is also the feature of three other Pachylaelaps (Longipachylaelaps) species, namely P. (L.) bifurciger, P. (L.) dubius and P. (L.) silviae. The new species may be reliably distinguished from the above mentioned congeners by the characters presented in Table
Comparative characteristics of the females of four similar species of the subgenus Pachylaelaps (Longipachylaelaps).
Character / Species | Pachylaelaps (L.) brevipilis sp. n. | Pachylaelaps (L.) bifurciger | Pachylaelaps (L.) dubius | Pachylaelaps (L.) silviae |
---|---|---|---|---|
Length of dorsal shield | 510‒565 μm | 910 μm | unknown | 836 μm |
Length of seta J1 | J1 ≈ ½ J1‒J2 | J1 ≈ ½ x J1‒J2 | J1 ≥ J1‒J2 | J1 < J1‒J2 |
Length of seta z6 | z6 < ½ z6‒Z1 | z6 ≈ ½ x z6‒Z1 | z6 ≤ z6‒Z1 | z6 > z6‒Z1 |
Length of seta J3 | J3 < ½ J3‒J4 | J3 < ½ J3‒J4 | J3 ≈ J3‒J4 | J3 < J3‒J4 |
Pilus dentilis | enlarged, spiniform | unknown | enlarged, spiniform | minute, setiform |
Genitoventral shield | longer than wide (1.05‒1.17) |
wider than long (0.87) |
longer than wide (1.18) |
as long as wide (≈ 1) |
Terminal epistome | densely crenelated | bifurcate | unknown | densely crenelated |
Spermathecal tubes | club-like distally, shorter (tips distant) |
worm-like distally, longer (tips adjacent) |
unknown (not detectable ?) |
strongly elongated, spirally convoluted |
Partial keys to the European species of Pachylaelaps may be found in
Due to vague and inadequate original descriptions, the particular structures of the sperm induction system, palptibial outgrowths and some other important characters remain unknown in a large number of species. Therefore several species are not included in the keys presented in this paper, namely Pachylaelaps (Pachylaelaps) bicornis Willmann, 1939 (♀), Pachylaelaps (Longipachylaelaps) dubius Hirschmann & Krauss, 1965 (♀), Pachylaelaps (Pachylaelaps) grandis Koroleva, 1977 (♀), Pachylaelaps (Longipachylaelaps) granulifer Hirschmann & Krauss, 1965 (♀, but ♂ included), Pachylaelaps (Longipachylaelaps) longisetis Halbert, 1915 (♂, but ♀ included), Pachylaelaps (Longipachylaelaps) obirensis Schmölzer, 1992 (♀, ♂).
1 | Dorsal setae J5 developed, needle-like; posterolateral margins of dorsal shield with one pair of slit-like poroid structures, gdS4 (subgenus Longipachylaelaps Mašán, 2007) | 2 |
– | Setae J5 vestigial; posterolateral margins of dorsal shield with two pairs of slit-like poroid structures, gdZ1 and gdS4 (subgenus Pachylaelaps s. str.) | 15 |
2 | Structures of sperm induction system between coxae IV well sclerotized (at least some basal or distal components), usually well discernible and striking in their lines | 3 |
– | Structures of sperm induction system weakly sclerotized, hyaline and transparent, scarcely detectable, often poorly developed or fully reduced | 12 |
3 | Sperm induction system tubular: tubiform structures simple, short or elongated, straight or curved, sometimes variously convoluted, or broadened distally | 4 |
– | Sperm induction system sacculate or otherwise modified: tubiform structures absent and transformed into saccules with short tubiform opening only slightly protuberant above enlarged base, or into specific sickle-shaped structures | 10 |
4 | Tubiform structures short and straight; movable digit of chelicera with three separate dents: distal hook (often with tiny lateral denticle), and subdistal and medial teeth; length of dorsal shield 750–800 μm | Pachylaelaps longisetis Halbert, 1915 |
– | Tubiform structures longer or otherwise formed; movable digit of chelicera with two separate dents: simple or bifid distal hook (often with tiny lateral denticle), and a subdistal tooth | 5 |
5 | Tubiform structures of sperm induction system intermediate in length (with their apices sufficiently separated) | 6 |
– | Tubiform structures long (with distalmost sections adjacent) | 8 |
6 | Dorsal setae short: setae J1 with tips reaching between insertions of setae J1 and J2; setae J4 slightly shorter than setae J5 (J4/J5 0.87–0.96); pilus dentilis conspicuously enlarged, spine-like; smaller species, length of dorsal shield 510–565 μm | Pachylaelaps brevipilis sp. n. |
– | Dorsal setae long: setae J1 with tips reaching beyond insertions of setae J2; setae J4 at least 1.5 longer than setae J5; pilus dentilis normal, slender; larger species, dorsal shield at least 680 μm in length | 7 |
7 | Tubiform structures regularly sclerotized; pilus dentilis minute, with upright position; dorsal setae J5 markedly shortened, about 5–6 times shorter than setae J4; genitiventral shield 260–320 μm wide; length of dorsal shield 770–890 μm | Pachylaelaps sublongisetis Koroleva, 1977 |
– | Medial portion of tubiform structures unsclerotized, hyaline; pilus dentilis larger, curved and directed backward; setae J5 less shortened, about 1.5–2.5 times shorter than setae J4; genitiventral shield 188–225 μm wide; length of dorsal shield 680–805 μm | Pachylaelaps longulus Willmann, 1938 |
8 | Tubiform structures excessively elongated, slightly tapered distally and helically convoluted (with 2–3 bends); length of dorsal shield 836 μm | Pachylaelaps silviae Moraza & Peña, 2005 |
– | Tubiform structures normal in length, straight or curved, and moderately broadened distally | 9 |
9 | Dorsal setae J5 shortened, about 4–7 times shorter than setae J4; length of dorsal shield 870 μm | Pachylaelaps squamifer Berlese, 1920 |
– | Setae J5 and J4 subequal in length; length of dorsal shield unknown | Pachylaelaps pulsator Hirschmann & Krauss, 1965 |
10 | Sperm induction system with specific sickle-shaped structures; pilus dentilis relatively robust, spine-like and directed backward; movable cheliceral digit with simple distal hook; genitiventral shield relatively narrower (length/width 1.14–1.27); length of dorsal shield 745–840 μm | Pachylaelaps distinctus Mašán, 2007 |
– | Sperm induction system sacculate: saccules with short tubiform opening slightly protuberant above enlarged base; pilus dentilis minute, with upright position; movable cheliceral digit with bifid distal hook; genitiventral shield relatively wider (length/width 0.92–1.12) | 11 |
11 | Sperm ductus inside saccules relatively shorter, straight and directed to anterior margin of coxa IV; base of saccules abutting the coxa IV; dorsal setae J5 30–39 μm long, about 2–3.5 times shorter than setae J4; genitiventral shield relatively narrower (length/width 1.03–1.12); length of dorsal shield 745–885 μm | Pachylaelaps vicarius Mašán, 2007 |
– | Sperm ductus inside saccules relatively longer, slightly curved and directed between coxae III and IV; base of saccules slightly widened, abutting the coxae III and IV; setae J5 20–25 μm long, about 5–7 times shorter than setae J4; genitiventral shield relatively wider (length/width 0.9–0.95); length of dorsal shield 940–1,050 μm | Pachylaelaps bocharovae Koroleva, 1978 |
12 | Tubiform structures of sperm induction system elongated (with more or less adjacent tips), straight or slightly curved | 13 |
– | Tubiform structures shortened (with well separated tips) or not detectable | 14 |
13 | Tubiform structures thin and long, worm-like; margins of genitiventral and anal shield straight and markedly separated; dorsal setae J4 and J5 short and subequal in length; epistome with distal projection narrow and bifurcate apically (often with small denticle between lateral cusps); length of dorsal shield 910 μm | Pachylaelaps bifurciger Berlese, 1920 |
– | Tubiform structures broadened, with slightly club-like tip; margins of genitiventral and anal shield undulate and closely abutting each other; setae J5 30–33 μm long, about 4–4.5 times shorter than setae J4; distal projection of epistome wide and densely crenelated anteriorly; length of dorsal shield 780–840 μm | Pachylaelaps undulatus Evans & Hyatt, 1956 |
14 | Tubiform structures short, broad, conical and delicately striated transversally; pilus dentilis relatively well developed, directed backward; dorsal setae J5 47–61 μm long, about 1.5–2 times shorter than setae J4; length of dorsal shield 685–835 μm | Pachylaelaps carpathicus Mašán, 2007 |
– | Tubiform structures not detectable (only rudimentary and tenuous structures rarely present); pilus dentilis small, with upright position; setae J5 15–25 μm long, about 3.5–6.5 times shorter than setae J4; length of dorsal shield 740–930 μm | Pachylaelaps perlucidus Mašán, 2007 |
15 | Two slit-like poroid structures well separated on posterolateral dorsal surface: gdZ1 situated between setae Z1–Z2 (close to Z2) and gdS4 between setae S4–S5 (close to S4) | 16 |
– | Two slit-like poroid structures with more adjacent position on posterolateral dorsal surface: gdZ1 and gdS4 situated between setae Z2 and S4, or close to setae Z2 | 18 |
16 | Cheliceral digits bidentate; length of dorsal shield 880 μm | Pachylaelaps denticulatus Hirschmann & Krauss, 1965 sensu Koroleva, 1977 |
– | Cheliceral digits multidentate: movable digit with 7–12 denticles | 17 |
17 | Lateromarginal and ventral soft integument with 11 pairs of setae; tubiform structures tenuous, worm-like and hyaline (hardly discernible); length of dorsal shield 615–670 μm | Pachylaelaps multidentatus Evans & Hyatt, 1956 |
– | Lateromarginal and ventral soft integument with 14 pairs of setae; tubiform structures relatively broad, tapered apically, directed posteromedially, weakly sclerotized but well discernible; length of dorsal shield 650–750 μm | Pachylaelaps bellicosus Berlese, 1920 |
18 | Tubiform structures of sperm induction system Y-shaped, with greatly widened bases, straight and tubular distal sections, and subglobular teat-like apices; basal part V-shaped, with well sclerotized sides | 19 |
– | Tubiform structures otherwise formed or not detectable | 20 |
19 | Openings of slit-like poroids gdZ1 and gdS4 closely adjacent; sternal surface with transversal linear pattern; genitiventral shield longer than wide (length/width 1.05–1.2); length of dorsal shield 720–970 μm | Pachylaelaps littoralis Halbert, 1915 |
– | Openings of slit-like poroids gdZ1 and gdS42 relatively separate; sternal region with transversal-longitudinal linear pattern; genitiventral shield usually subequal in length and width (length/width 0.95–1.1); length of dorsal shield 690–860 μm | Pachylaelaps pectinifer (G. & R. Canestrini, 1882) |
20 | Sperm induction system with short, conical to cylindrical, and evenly sclerotized structures | 21 |
– | Sperm induction system not detectable or with normal, elongated and tubiform structures | 24 |
21 | Lateromarginal and ventral soft integument with 9–10 pairs of setae; cheliceral digits slim and elongated: subdistal and submedial tooth of movable digit small, subequal in size and with well separated position; length of dorsal shield 680–800 μm | Pachylaelaps resinae Karg, 1971 |
– | Lateromarginal and ventral soft integument with 15–16 pairs of setae; cheliceral digits relatively shorter: movable digit with more adjacent subdistal and submedial tooth, submedial tooth distinctly larger than small subdistal tooth | 22 |
22 | Smaller species with dorsal shield under 850 μm in length (sternal shield less than 275 μm in length, genitiventral shield less than 305 μm in width); transversal curved sculptural line on sternal surface between setae st2 discontinuous medially; length of dorsal shield 750–800 μm | Pachylaelaps terreus Mašán, 2007 |
– | Larger species with dorsal shield more than 850 μm in length (sternal shield more than 275 μm in length, genitiventral shield more than 305 μm in width); transversal curved sculptural line on sternal surface continuous | 23 |
23 | Sclerotized structures with sperm ductus stout, widened basally and completely abutting inner surface of coxae IV, and relatively short (with well separate apices); length of dorsal shield 880–1,022 μm | Pachylaelaps insularis Berlese, 1920 |
– | Sclerotized structures with sperm ductus slim, narrow, and relatively long; length of dorsal shield 950–1,140 μm | Pachylaelaps imitans Berlese, 1920 |
24 | Smaller species with dorsal shield under 950 μm in length; tubiform structures of sperm induction system evenly sclerotized and relatively shorter (with their apices sufficiently separated); dorsolateral and ventral soft integument with 11 pairs of setae | Pachylaelaps pyrenaicus sp. n. |
– | Larger species with dorsal shield between 1,150 and 1,400 μm in length; tubiform structures not detectable (unsclerotized or absent), or unevenly sclerotized and obviously elongate, with adjacent apical or distal sections; apical or distal section of tubes more sclerotized than basal part; dorsolateral and ventral soft integument with at least 13 pairs of setae | 25 |
25 | Tubiform structures well developed, relatively long | 26 |
– | Tubiform structures not detectable | 28 |
26 | Tubiform structures penis-like, straight or slightly curved, directed anteriorly, with slightly broadened base and more sclerotized tip; length of dorsal shield 1,185–1,330 μm | Pachylaelaps armimagnus Mašán, 2007 |
– | Tubiform structures more elongated, worm-like to saccule-like, well broadened basally, strongly curved and directed posteriorly | 27 |
27 | Distal portions of tubiform structures relatively wide, saccule-like, closely adjacent, and uniformly sclerotized; lateromarginal and ventral soft integument with 13–14 pairs of setae; length of dorsal shield 1,320–1,350 μm | Pachylaelaps sacculimagnus Mašán, 2007 |
– | Distal portions of tubiform structures narrow, worm-like, well distant, and with thickened terminal sclerotization; lateromarginal and ventral soft integument with 15 pairs of setae; length of dorsal shield 1,180–1,310 μm | Pachylaelaps troglophilus Willmann, 1940 |
28 | Lateromarginal and ventral soft integument with increased number of 20–21 pairs of setae; genitiventral shield relatively narrower (length/width 1.08–1.19); length of dorsal shield 1,245–1,300 μm | Pachylaelaps ensifer Oudemans, 1904 |
– | Lateromarginal and ventral soft integument with 15 pairs of setae; genitiventral shield relatively wider (length/width 0.96–1.05); length of dorsal shield 1,190–1,400 μm | Pachylaelaps carpathimagnus Mašán, 2007 |
1 | Dorsal setae J5 well developed, needle-like; posterolateral margins of dorsal shield with one pair of slit-like poroid structures, gdS4 (subgenus Longipachylaelaps Mašán, 2007) | 2 |
– | Setae J5 vestigial; posterolateral margins of dorsal shield with two pairs of slit-like poroid structures, gdZ1 and gdS4 (subgenus Pachylaelaps s. str.) | 18 |
2 | Apex of cheliceral spermatodactyl with special horseshoe-like process; length of dorsal shield 810 μm | Pachylaelaps virago Berlese, 1920 |
– | Apex of spermatodactyl regularly formed, never with additional process | 3 |
3 | Cheliceral spermatodactyl wider, with obvious basal or medial expansion and narrow distal section | 4 |
– | Spermatodactyl narrower, sword-like to stiletto-like, with almost parallel lateral margins in medial section and moderately tapered distal section | 7 |
4 | Cheliceral spermatodactyl widened in basal section and relatively longer (spermatodactyl length/movable digit length 2.9–3.3); dorsal setae J5 less than two times longer than setae J4 | 5 |
– | Spermatodactyl widened in medial section and relatively shorter (spermatodactyl length/movable digit length 1.8–2.3); setae J5 at least two times shorter than setae J4 | 6 |
5 | Dorsal setae J5 and J4 subequal in length; length of dorsal shield unknown | Pachylaelaps pulsator Hirschmann & Krauss, 1965 |
– | Dorsal setae J5 about 1.5 times shorter than setae J4; length of dorsal shield unknown | Pachylaelaps longicrinitus Hirschmann & Krauss, 1965 |
6 | Dorsal setae J5 less shortened, about 2–3.5 times shorter than setae J4; two petal-like palptibial projections basally fused; length of dorsal shield 670–735 μm | Pachylaelaps distinctus Mašán, 2007 |
– | Setae J5 more shortened, about 4–7 times shorter than setae J4; two petal-like palptibial projections free; length of dorsal shield 750 μm | Pachylaelaps squamifer Berlese, 1920 |
7 | Petal-like palptibial projections smaller, shorter than cross-sectional radius of palptibia | 8 |
– | Petal-like palptibial projections larger, longer than cross-sectional radius of palptibia | 11 |
8 | Dorsal setae J4 and J5 subequal or only negligibly differing in length; dorsocentral setae shorter: setae J1 with tips reaching between insertions of setae J1 and J2 | 9 |
– | Dorsal setae J4 at least 1.5 times longer than setae J5; dorsocentral setae longer: setae J1 with tips reaching or overlapping the insertions of setae J2 | 10 |
9 | Cheliceral spermatodactyl laterally flattened, sword-like, shorter (less than two times the movable digit); most dorsal setae short: z6 < z6‒Z1, s4 < s4‒s5, Z2 < Z2‒Z3; length of dorsal shield 470–510 μm | Pachylaelaps brevipilis sp. n. |
– | Spermatodactyl tubular, slightly sinuous, spear-shaped, longer (about three times the movable digit); most dorsal setae long: z6 > z6‒Z1, s4 > s4‒s5, Z2 > Z2‒Z3; length (mean) of dorsal shield 836 μm | Pachylaelaps silviae Moraza & Peña, 2005 |
10 | Cheliceral spermatodactyl widest in distal section; length of dorsal shield unknown | Pachylaelaps granulifer Hirschmann & Krauss, 1965 |
– | Spermatodactyl widest in basal section; length of dorsal shield unknown | Pachylaelaps gibbosus Hirschmann & Krauss, 1965 |
11 | Two palptibial projections with parallel contiguous margins and adjacent apices | 12 |
– | Two palptibial projections with divergent contiguous margins and apices well separated | 13 |
12 | Larger palptibial projection with widely rounded anterior margin; dorsal setae J5 38–51 μm long, about 1.5–2.5 times shorter than setae J4 (70–92 μm long); length of dorsal shield 645–735 μm | Pachylaelaps longulus Willmann, 1938 |
– | Larger palptibial projection regularly tapered and with obtusely pointed apex; setae J5 about 30 μm long, about four times shorter than setae J4 (120–130 μm long); length of dorsal shield 710–780 μm | Pachylaelaps sublongisetis Koroleva, 1977 |
13 | One of the palptibial projections with needle-like process on distal margin | 14 |
– | Palptibial projections never with needle-like process on distal margin | 15 |
14 | Distal margin of larger palptibial projection irregular, with two apices: anteriorly directed apex needle-like, laterally situated apex expanded and widely rounded; cheliceral spermatodactyl wider, with small subapical incision; length of dorsal shield 640–715 μm | Pachylaelaps carpathicus Mašán, 2007 |
– | Distal margin of larger palptibial projection regularly curved, with one needle-like apex directed laterally; spermatodactyl narrower, with regularly tapered apex; length of dorsal shield 870–950 μm | Pachylaelaps bocharovae Koroleva, 1978 |
15 | Cheliceral spermatodactyl relatively longer (spermatodactyl length/movable digit length 1.8–2.4) | 16 |
– | Spermatodactyl relatively shorter (spermatodactyl length/movable digit length 1.6–1.8) | 17 |
16 | Terminal hook of cheliceral fixed digit bifid; cheliceral spermatodactyl relatively shorter (spermatodactyl length/movable digit length 1.8–2); length of dorsal shield 745–900 μm | Pachylaelaps perlucidus Mašán, 2007 |
– | Terminal hook of cheliceral fixed digit simple; spermatodactyl relatively longer (spermatodactyl length/movable digit length 2.2–2.4); length of dorsal shield unknown | Pachylaelaps conifer Hirschmann & Krauss, 1965 |
17 | Dorsal setae relatively longer: setae J3 with tips reaching to the bases of setae J5; cheliceral spermatodactyl relatively shorter (spermatodactyl length/movable digit length 1.6); length of dorsal shield unknown | Pachylaelaps decipiens Hirschmann & Krauss, 1965 |
– | Dorsal setae relatively shorter: setae J3 with tips reaching between the bases of setae J3 and J5; spermatodactyl relatively longer (spermatodactyl length/movable digit length 1.8); length of dorsal shield unknown | Pachylaelaps hestulifer Hirschmann & Krauss, 1965 |
18 | Tarsus II with one spur-like distal seta (pl1) | 19 |
– | Tarsus II with two spur-like distal setae (pl1, pl2) | 23 |
19 | Palptibial projections wider, each with widely rounded apex; cheliceral spermatodactyl with at least one small lobe-like convexity situated on ventral proximal margin | 20 |
– | Palptibial projections narrower, at least one of them with needle-like apex; cheliceral spermatodactyl with straight margins, without lobe-like convexities on its margins | 21 |
20 | Two slit-like poroid structures on posterolateral dorsal surface well separated: gdZ1 situated between setae Z1–Z2 (close to Z2) and gdS4 between setae S4–S5 (close to S4); length of dorsal shield 760–840 μm | Pachylaelaps denticulatus Hirschmann & Krauss, 1965 sensu Koroleva, 1977 |
– | Two slit-like poroid structures with more adjacent position on posterolateral dorsal surface: gdZ1 and gdS4 situated close to setae Z2 | Pachylaelaps pyrenaicus sp. n. |
21 | Cheliceral spermatodactyl with two small lobe-like convexities situated on dorsal distal margin and ventral proximal margin; length of dorsal shield 740 μm | Pachylaelaps terreus Mašán, 2007 |
– | Spermatodactyl with one small lobe-like convexity situated on ventral proximal margin | 22 |
22 | Larger species, dorsal shield more than 750 μm in length; length of dorsal shield 980 μm | Pachylaelaps imitans Berlese, 1920 |
– | Smaller species, dorsal shield less than 750 μm in length; length of dorsal shield 610–665 μm | Pachylaelaps resinae Karg, 1971 |
23 | Palptibia smooth, without projections | 24 |
– | Palptibia with projections | 25 |
24 | Openings of slit-like poroids gdZ1 and gdS4 closely adjacent; projection on genu II small, subconical, with thin and rounded apex; cheliceral spermatodactyl about 1.5 times longer than movable digit; length of dorsal shield 700–830 μm | Pachylaelaps littoralis Halbert, 1915 |
– | Openings of slit-like poroids gdZ1 and gdS42 relatively separate; projection on genu II robust, subcylindrical, with flat to truncate apex; spermatodactyl about two times longer than movable digit; length of dorsal shield 650–770 μm | Pachylaelaps pectinifer (G. & R. Canestrini, 1882) |
25 | Smaller species with dorsal shield less than 1,000 μm in length; palptibia with two projections; cheliceral spermatodactyl relatively shorter (spermatodactyl length/movable digit length about 1.6); length of dorsal shield 825–840 μm | Pachylaelaps insularis Berlese, 1920 |
– | Larger species with dorsal shield more than 1,000 μm in length; palptibia with 2–4 projections; cheliceral spermatodactyl relatively longer (spermatodactyl length/movable digit length more than 2.5) | 26 |
26 | Palptibia thickened: palptibial petal-like projections well developed and sclerotized, longer than cross-sectional radius of palptibia; proximal section of cheliceral spermatodactyl relatively wide and with punctate ornamentation on surface | 27 |
– | Palptibia normal: palptibial petal-like projections weakly developed and sclerotized, shorter than cross-sectional radius of palptibia; proximal section of spermatodactyl relatively narrow and without punctation | 29 |
27 | Palptibia with two petal-like projections and a setiform structure, smaller petal-like projection with spinous apex; cheliceral spermatodactyl with small convexity on ventral proximal margin; length of dorsal shield 1,080–1,170 μm | Pachylaelaps troglophilus Willmann, 1940 |
– | Palptibia with three petal-like projections (one of them with spinous apex) and a setiform structure; spermatodactyl without small convexity on ventral margin | 28 |
28 | Setiform structure associated with palptibial projections simple, tenuous and tubular; cheliceral spermatodactyl with regularly convergent lateral margins, lanceolate in subdistal part; length of dorsal shield 1,245–1,255 μm | Pachylaelaps armimagnus Mašán, 2007 |
– | Setiform structure associated with palptibial projections flattened, plank-like, bifurcate apically, with two sharp points; spermatodactyl knife-like, with almost parallel lateral margins, slight subapical narrowing and rostrum-like tip; length of dorsal shield 1,230–1,360 μm | Pachylaelaps sacculimagnus Mašán, 2007 |
29 | Palptibia with two separate or fused scale-like projections, the projections with rounded or obtusely pointed distal margin; length of dorsal shield 1,235–1,245 μm | Pachylaelaps ensifer Oudemans, 1904 |
– | Palptibia with four scale-like projections, the largest lateral projection hook-shaped subapically, sharply pointed; length of dorsal shield 1,170–1,325 μm | Pachylaelaps carpathimagnus Mašán, 2007 |
This study was supported by the Scientific Grant Agency of the Ministry of Education of Slovak Republic and the Academy of Sciences [VEGA Grant No. 2/0091/14: Arboricolous mites (Acari: Mesostigmata) associated with wood-destroying insects and fungi in Slovakia, with consideration on taxonomy, ecology and chorology of individual species.].