Pachylaelaps (Longipachylaelaps)

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 : 112-113

Key to known species of the subgenus Pachylaelaps (Longipachylaelaps) (females)

Partial keys to European species of Pachylaelaps may be found in Karg (1971, 1993), Koroleva (1977), Mašán (2007a), and Mašán et al. (2016). A new key to the subgenus Longipachylaelaps is needed to include a species described recently from Turkey ( Özbek , 2015), the four new species described in this study, and a revised species of Hirschmann & Krauss (1965), namely P. (L.) granulifer , based on numerous specimens collected in Portugal ( 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, lgt. P. Fenďa, det. P. Mašán) .

The identification of Pachylaelaps species is complicated by the incomplete descriptions of some species. Therefore some species are not included in the keys presented in this paper, namely Pachylaelaps (Longipachylaelaps) dubius Hirschmann & Krauss, 1965 and P. (L.) obirensis Schmölzer, 1992 , including also the two dubious species P. (L.) gallicus Berlese, 1920 and P. (L.) tetragonoides Dugès, 1834 . The male described under the name P. (L.) longisetis Halbert, 1915 by Evans & Hyatt (1956) is considered here as a misidentification of P. (L.) undulatus Evans & Hyatt, 1956 , but this suggestion needs to be verified by further study. The keys below contain 26 species of which 15 species are based on both adult stages, six species exclusively on males ( conifer , decipiens , gibbosus , hestulifer , longicrinitus , and virago ), and five species only on females ( anatolicus , bifurciger , longisetis , undulatus , and vicarius ). The identification key for male stages is newly developed for the purposes of this paper. The key to identification of females is derived from that by Mašán (2007a).

1. Cheliceral digits polydentate, each with at least ten denticles; central projection of epistome apically pointed, lanceolate; length of dorsal shield 720–810 µm............................................... P. (L.) anatolicus Özbek, 2015

- Cheliceral digits oligodentate, each with at most five denticles; central projection of epistome apically widened, with anterior margin densely crenellated............................................................................. 2

2. Structures of sperm induction system between coxae IV well sclerotised (at least some basal or distal components), usually well discernible and striking in their lines ( Figs 10–13 , 23–26 , 49–52 , 57–61 ).................................... 3

- Structures of sperm induction system weakly sclerotised, hyaline and transparent, scarcely detectable, often poorly developed or fully reduced ( Fig. 62 )............................................................................. 16

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 ( Fig. 61 ), or into specific sickle-shaped structures ( Fig. 60 ).................................................................................................... 14

4. Movable digit of chelicera tridentate; tubiform structures of sperm induction system short and narrow, straight or slightly curved, regularly sclerotised ( Fig. 57 ); length of dorsal shield 750–800 µm............... P. (L.) longisetis Halbert, 1915

- Movable digit of chelicera bidentate; tubiform structures longer, often irregularly sclerotised, and otherwise formed as depicted in Fig. 57................................................................................... 5

5. Tubiform structures of sperm induction system shorter, with their apices separated ( Figs 23–26 , 51, 52 , 58, 59 ).......... 6

- Tubiform structures longer, with their apices or distal sections adjacent, sometimes with bends ( Figs 10–13 , 49, 50 )..... 10

6. Dorsal setae short: setae J1 (= 25–30 µm) 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; tubiform structures of sperm induction system with narrow base and club-like apice ( Fig. 58 ); smaller species, length of dorsal shield 510–565 µm................................................................................... P. (L.) brevipilis Mašán, Özbek & Fenďa, 2016

- Dorsal setae long: setae J1 (= 60–95 µm) with tips reaching to or beyond insertions of setae J2; setae J4 at least 1.5 as long as setae J5; pilus dentilis not hypertrophied, slender; larger species, dorsal shield at least 680 µm in length................ 7

7. Dorsal setae J5 markedly shortened, about 5–6 times shorter than setae J4; tubiform structures os sperm induction system reg-

ularly sclerotised; pilus dentilis minute, with upright position; length of dorsal shield 770–890 µm.............................................................................................. P. (L.) sublongisetis Koroleva, 1977 - Setae J5 less shortened, about 1.4–2.2 times shorter than setae J4; basal or medial portion of tubiform structures unsclerotised, hyaline; pilus dentilis larger, curved and directed backward................................................... 8

8. Tubiform structures of sperm induction system with less sclerotised medial portion and well sclerotised narrow base ( Fig. 59 ); length of dorsal shield 680–805 µm.............................................. P. (L.) longulus Willmann, 1938

- Tubiform structures with less sclerotised and slightly expanded basal portion ( Figs 23–26 , 51, 52 ).................... 9

9. Tubiform structures of sperm induction system larger, as in Figs 23–26 ; genitiventral shield subequal in length and width (289–318 µm long, 289–310 µm wide, L/ W 0.93 –1.05); anterior sections of peritremes longer, with tips reaching close to dorsal setae z1; length of dorsal shield 780–925 µm....................................... P. (L.) bergomensis sp. nov.

- Tubiform structures smaller, as in Figs 51, 52 ; genitiventral shield oblong (246–284 µm long, 203–225 µm wide, L/ W 1.2 – 1.28); anterior sections of peritremes shorter, with tips reaching between setae z1 and z2; length of dorsal shield 665–800 µm.................................................................................. P. (L.) pantinii sp. nov.

10. Tubiform structures of sperm induction system conspicuously elongated, with 1–3 bends ( Figs 10–13 )............... 11

- Tubiform structures shorter, straight or regularly curved ( Figs 49, 50 ).......................................... 12

11. Tubiform structures of sperm induction system helically convoluted, with 2–3 bends in medial and distal portions; dorsal setae J4 and J5 subequal in length; soft integument with 14 pairs of setae (six pairs of r-R setae and eight pairs of Jv-Zv setae); length of dorsal shield 836 µm............................................... P. (L.) silviae Moraza & Peña, 2005

- Tubiform structures with one subterminal bend, as in Figs 10–13 ; setae J4 as long as setae J5 (J4/J5 1.43–1.98); soft integument with 16 pairs of setae (seven pairs of r-R setae and nine pairs of Jv-Zv setae); length of dorsal shield 785–845 µm...................................................................................... P. (L.) abludens sp. nov.

12. Dorsal setae J5 shortened (17.5 µm long), more than three times shorter than setae J4; tubiform structures of sperm induction system terminally truncate; length of dorsal shield 870 µm............................ P. (L.) squamifer Berlese, 1920

- Setae J5 normal in length (± 40 µm long), never more than two times shorter than setae J4; tubiform structures terminally rounded........................................................................................... 13

13. Dorsal setae shorter: setae J1 with tips not reaching insertions of following setae J2; setae J5 shorter than setae J4 (J4/J5 1.45– 1.8); length of dorsal shield 830–865 µm............................................. P. (L.) marcovallei sp. nov.

- Dorsal setae longer: setae J1 with tips reaching beyond insertions of setae J2; setae J4 and J5 subequal in length (J5 less than 1.4 times shorter than setae J5); length of dorsal shield unknown............. P. (L.) pulsator Hirschmann & Krauss, 1965

14. Sperm induction system with specific sickle-shaped structures ( Fig. 60 ); 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............................................... P. (L.) 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)................................................................................... 15

15. Sperm ductus inside saccules relatively shorter, straight and directed to anterior margin of coxa IV; base of saccules abutting the coxa IV ( Fig. 61 ); dorsal setae J 5 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.................... P. (L.) 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 J 5 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........... P. (L.) bocharovae Koroleva, 1978

16. Tubiform structures of sperm induction system elongated (with more or less adjacent tips), straight or slightly curved.... 17

- Tubiform structures shortened (with well separated tips) or not detectable...................................... 18

17. Tubiform structures thin and long, worm-like; opposite 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............... P. (L.) bifurciger Berlese, 1920

- Tubiform structures broadened, with slightly club-like tip; opposite margins of genitiventral and anal shield undulate and closely abutting each other; setae J 5 30–33 µm long, about 4–4.5 times shorter than setae J4; distal projection of epistome wide and densely crenulated anteriorly; length of dorsal shield 780–840 µm............ P. (L.) undulatus Evans & Hyatt, 1956

18. Tubiform structures short, broad, conical and delicately striated transversally ( Fig. 62 ); length of dorsal shield 685–835 µm............................................................................. P. (L.) carpathicus Mašán, 2007

- Tubiform structures not detectable, absent................................................................ 19

19. Dorsal setae J5 shortened (15–25 µm long), more than three times shorter than setae J4 (82–105 µm long); genitiventral shield 240–300 µm wide, relatively narrower (L/W 0.97–1.11); soft integument with 16 pairs of setae (seven pairs of r-R setae and nine pairs of Jv-Zv setae); smaller species, length of dorsal shield 740–930 µm............ P. (L.) perlucidus Mašán, 2007

- Dorsal setae J5 normal (50–66 µm long), less than 1.5 times shorter than setae J4 (60–78 µm long); genitiventral shield 375– 450 µm wide, relatively wider (L/W 0.86–0.97); soft integument with 14 pairs of setae (six pairs of r-R setae and eight pairs of Jv-Zv setae); larger species, length of dorsal shield 990–1,085 µm......... P. (L.) granulifer Hirschmann & Krauss, 1965

Figures

FIGURES 10 – 13. Pachylaelaps (Longipachylaelaps) abludens sp. nov., sperm induction structures, female, variant forms. 10 ‒ 11. Normal forms; 12 ‒ 13. Aberrant forms in strongly pressed specimens. Not scaled.

FIGURES 23 – 26. Pachylaelaps (Longipachylaelaps) bergomensis sp. nov., sperm induction structures, female, variant forms. Not scaled.

FIGURES 49 – 52. Sperm induction structures, females, variant forms. 49 ‒ 50. Pachylaelaps (Longipachylaelaps) marcovallei sp. nov. (49. Normal form; 50. Aberrant form in strongly pressed specimen); 51 ‒ 52. Pachylaelaps (Longipachylaelaps) pantinii sp. nov. (51. Normal form; 52. Aberrant form in strongly pressed specimen). Not scaled.

FIGURES 57 – 62. Sperm induction structures, females. 57. Pachylaelaps (Longipachylaelaps) longisetis; 58. Pachylaelaps (Longipachylaelaps) brevipilis; 59. Pachylaelaps (Longipachylaelaps) longulus; 60. Pachylaelaps (Longipachylaelaps) distinctus; 61. Pachylaelaps (Longipachylaelaps) vicarius; 62. Pachylaelaps (Longipachylaelaps) carpathicus. Not scaled.