Pachylaelapidae, Berlese, 1913

MAŠÁN, PETER & HALLIDAY, BRUCE, 2014, Review of the mite family Pachylaelapidae (Acari: Mesostigmata), Zootaxa 3776 (1), pp. 1-66 : 7-8

Key to subfamilies, tribes, genera and subgenera of Pachylaelapidae (females)

1. Epigynal shield free from ventral shield, simple, subrectangular to subtriangular, truncate posteriorly, with a pair of setae; anal shield fused with ventral shield to form a suboval or subtriangular ventri-anal shield, ventri-anal shield with 2–4 pairs of preanal setae................................................................... Pachyseiinae Karg, 1971 … 2

- Epigynal plate posteriorly expanded, fused with ventral or ventri-anal shield to form a genitiventral or geniti-ventri-anal shield bearing more than one pair of setae; anal shield free or fused with genitiventral shield to form a suboval geniti-ventri-anal shield, geniti-ventri-anal shield with 3–5 pairs of pre-anal setae................................................ 3

2. Tarsus II with 1–3 distal setae modified, spur-like; stigmata and peritremes normally formed, peritremes shorter, with anterior ends situated between setae z1 and z2, clearly distant from insertions of vertical setae; setae on soft posteroventral integument simple and needle-like; infundibulum of some glands on dorsal and/or peritrematal shields usually modified, markedly enlarged, cavity-like and well sclerotised.............................................. Pachyseius Berlese, 1910

- Tarsus II with setae uniform, simple and needle-like or spine-like; stigmata and peritremes hypertrophied, peritremes longer, with anterior ends reaching close to setae j1; some setae on soft posteroventral integument modified, apically bifurcated or brush-shaped; infundibulum of all glands on dorsal and ventral surface normal and never modified into enlarged cavity-like structures..................................................................... Mirabulbus Liu & Ma, 2001

3. Dorsal shield with full complement of J, Z and S opisthonotal setae (with at least 15 pairs of these setae), never hypertrichous; a pair of presternal plates present; tarsus II with spur-like distal seta al1; palp apotele 2-tined; epistome nearly truncate.............................................................................. Pachyseiulinae Mašán, 2007 … 4

- Dorsal shield with reduced complement of opisthonotal setae (with at most 12 pairs of these setae, Z4, Z5 and S2 always absent, S1 rarely absent), or hypertrichous; presternal plates absent; seta al1 of tarsus II simple, needle- to spine-like; palp apotele 3-tined; epistome produced into medial anteriorly-directed projection............ Pachylaelapinae Berlese, 1913 … 5

4. Genitiventral shield with four pairs of setae; dorsal shield with 37 pairs of setae (R1 and R2 situated on the shield); metasternal setae st4 situated on endopodal section of fused sternal/endopodal shields......... Pachyseiulus Moraza & Johnston, 1990

- Genitiventral shield with two pairs of setae; dorsal shield with 35 pairs of setae (R1 on soft integument, R2 absent); metasternal setae st4 situated in soft integument............................................. Pseudopachys Berlese, 1916

5. Genitiventral shield free, relatively small, not markedly enlarged behind ventral setae Jv1, clearly separated from anal shield and posterior ends of peritrematal shields; parapodal portion of peritrematal shields not strongly developed behind coxa IV, always free; dorsal shield with 30–38 pairs of setae; tarsi with minute claws and well developed empodium, tarsus II without distal setae modified into spurs................................................... Paralaelapini new tribe … 6

- Genitiventral shield markedly enlarged behind ventral setae Jv1, closely adjacent to anal shield, fused with or touching posterior ends of peritrematal shields; parapodal portion of peritrematal shields strongly developed behind coxa IV; dorsal shield with at most 30 pairs of setae, or hypertrichous; tarsi with normal claws and empodium, tarsus II with 0–2 distal setae spur-like .................................................................................................... 8

6. Soft integument strongly hypertrichous; dorsal shield setae uniformly long, tips reaching beyond the bases of following setae.............................................................................. Paralaelaps Trägårdh, 1908

- Soft integument with normal chaetotaxy; some dorsal shield setae short to minute....... Elaphrolaelaps Berlese, 1910 … 7

7. Sternal shield entire, without posterior incision; dorsal shield setae short and mostly subequal in length........................................................................................... Elaphrolaelaps (Elaphrolaelaps)

- Sternal shield with deep incision on posterior margin, at least to the level between setae st1 and st2; dorsal shield with some marginal setae markedly elongated................................... Elaphrolaelaps (Incisosternum) Elsen, 1974

8. Sperm access system associated with coxae IV ( Figs 3, 4 ); genu I with 11 or 13 setae (2-5/2-2 or 2-6/3-2); hypostomal corniculi long, sword-like; tarsus II with two distal setae modified (pl1, pl2), spur-like (in two Olopachys species , seta pl2 simple and needle-like)........................................................... Pachylaelapini Berlese, 1913 … 9

- Sperm access system associated with coxae III ( Figs 1, 2 ); genu I with 12 or 14 setae (2-5/3-2 or 2-6/4-2); hypostomal corniculi short, horn-like; tarsus II with at most one distal seta modified (pl1), spur-like Onchodellini Mašán, 2007 ........ 13

9. Anal and genitiventral shields fused to form a geniti-ventri-anal shield bearing 3–5 pairs of pre-anal setae and three circumanal setae....................................................................... Olopachys Berlese, 1910 … 10

- Anal shield free from ventral shield, simple, subtriangular, bearing only three circumanal setae...................... 11

10. Setae J5 minute; sperm access system with tubular components; pilus dentilis on fixed digit of chelicerae minute, with normal upright position or directed anteriorly................................................... Olopachys (Olopachys)

- Setae J5 normally developed, needle-like; sperm access system with sacculated and lobe-like structures; pilus dentilis on fixed digit of chelicerae relatively large and curved posteriorly..................... Olopachys (Olopachylaella) Mašán, 2007

11. Dorsal shield with 29 pairs of setae (S1 absent); chaetotaxy of some leg segments deficient: femur I with 12 setae (2-5/3-2), genu I and tibia I with 11 setae (2-5/2-2), genu III with six setae (1-4/0-1); R setae on soft integument absent; epistome produced into lanceolate and apically bifurcate projection................................ Neopachylaelaps Mašán, 2007

- Dorsal shield with 30 pairs of setae (S1 present); leg chaetotaxy normal: femur I (2-5/4-2) and genu I (2-6/3-2) with 13 setae, tibia I with 12 setae (2-5/3-2), genu III with seven setae (1-4/1-1); at least one R seta present on soft integument; epistome otherwise formed............................................................. Pachylaelaps Berlese, 1888 … 12

12. Setae J5 minute; posterolateral margins of dorsal shield with two pairs of hypertrophied slit-shaped gland pores (gdZ1, gdS4)............................................................................. Pachylaelaps (Pachylaelaps)

- Setae J5 normally developed, needle-like; posterolateral margins of dorsal shield with one pair of hypertrophied slit-shaped gland pores (gdS4).............................................. Pachylaelaps (Longipachylaelaps) Mašán, 2007

13. Genitiventral shield with three pairs of setae (st5, Jv1, Zv2); setae j1 minute; soft integument with five pairs of setae............................................................................ Chaetodellus Mašán & Halliday, 2013

- Genitiventral shield with two pairs of setae (Zv2 off the shield); setae j1 normally developed, needle-like; soft integument with at least seven pairs of setae............................................................................. 14

14. Tarsus II without distal setae modified into a spur; soft integument hypertrichous (at least 35 pairs of setae present)...... 15

- Tarsus II with distal seta pl1 modified, spur-like; soft integument with normal or deficient chaetotaxy (at most 15 pairs of setae present)............................................................................................ 16

15. Dorsal shield with 30 pairs of setae; some dorsal shield setae modified, elongated and thickened, with club-like tips; leg chaetotaxy normal: genu I with 12 setae (2-5/3-2), genu III with seven setae (1-4/1-1), femur IV with six setae (1-3/1-1)................................................................................. Sphaerolaelaps Berlese, 1903

- Dorsal shield with about 80 pairs of setae; all dorsal shield setae uniform, simple and needle-like; most leg segments with increased number of setae: genu I with 14 setae (2-6/4-2), genu III with ten setae (2-4/2-2), femur IV with 11 setae (2-4/3-2)......................................................................... Pachysphaerolaelaps Mašán, 2007

16. Idiosoma subglobular; dorsal shield strongly vaulted, hemispherical, expanded ventrally and covering margins of ventral surface, with 29 pairs of unequal setae; setae J5 inserted with some other marginal dorsal shield setae on ventral expansion of the shield; soft integument with seven pairs of setae............................... Pachyglobolaelaps Mašán , new genus

- Idiosoma dorso-ventrally flattened; dorsal shield flat to slightly convex, covering only dorsal surface, with 30 pairs of subequal setae; all dorsal shield setae inserted dorsally; soft integument with more than seven pairs of setae, usually 10–15 pairs... 17

17. Setae J5 minute; sperm access system with tubular structures strongly reduced (not observable), tube concealed in coxa (in P. sculptus group, also short tubiform opening slightly protuberant above margin of coxa III present)...................................................................................................... Pachydellus Mašán, 2007

- Setae J5 normally developed, needle-like; sperm access system with tubular structures well developed, tubes long and fine... .................................................................................................. 18

18. Long-legged forms, legs I and IV markedly longer than dorsal shield; genu IV with 8 setae (2-4/1-1) and tibia IV with 9 setae (2-3/2-2)................................................................... Pachylaelapsoides Mašán, 2007

- Short-legged forms, legs I and IV shorter than dorsal shield; genu IV (1-4/1-1) and tibia IV (1-3/2-1) with 7 setae........................................................................................ Onchodellus Berlese, 1904

Figures

FIGURES 1–4. Pachylaelapidae species, females, coxae III and IV showing attachment of sperm induction tubes. 1. Onchodellus slovacus; 2. Pachydellus sculptus; 3. Olopachys suecicus; 4. Pachylaelaps longulus. Based on Mašán (2007a).