Pachyseius anisimovi, Marchenko, Irina I., 2015

Marchenko, Irina I., 2015, A new species of Pachyseius Berlese (Acari: Pachylaelapidae) from South Siberia (Russia), with a key to the species known from Asia, Zootaxa 3905 (2), pp. 221-232 : 222-230

Pachyseius anisimovi sp. nov.

Diagnosis. Dorsal shield with dorsocentral setae only slightly shorter than other dorsal setae; a pair of well sclerotised presternal shields present; ventri-anal shield with two pairs of pre-anal setae (Jv1, Jv2); ventrolateral margins of soft integument with six pairs of setae (r6, R1, R3, R4, R6, R7), opisthogastric region with five pairs of setae (Jv3-Jv5, Zv3, Zv4); metasternal shields free, subtriangular, densely micropunctate; peritrematal shields not fused with exopodal shields; posterior tips of peritrematal shields extending beyond exopodal shields IV; peritrematal shield expanded close to stigma; metapodal shields separated from antero-lateral margins of ventrianal shield; trochanter I with five setae; femur I with 12 setae; tarsus II with two distal spur-like setae; tarsus IV of female with 17 setae.

Description. Female ( Figs 1–9 , 23 specimens measured)

Dorsal idiosoma ( Fig. 1 ). Dorsal shield entire, oval, smooth anteriorly, with punctiform reticulate pattern on opisthonotal surface, 625–775 long, 340–425 wide, length/width 1.76–1.86. Dorsal shield with 30 pairs of acicular setae. Bases of j 1 setae adjacent. Podonotal region with seven pairs of poroids including enlarged, cavity-like glands gdj 3 and slit-like lyrifissures idj 1 between setae j 2 and z 2. Two pairs of small, oval, dark-coloured spots between setae j2 and j3, apparently under the dorsal shield and visible through the cuticle ( Fig. 2 ). Opisthonotal region with 13 pairs of poroids. Length of setae: j1 (18–30), j2 (23–40), j3 (25–50), j4 (25–37), j5 (25–32), j6 (25–37), z1 (7–10), z2 (25–50), z4 (33–55), z5 (25–30), z6 (25–33), s2 (25–37), s4 (25–50), s5 (25–45), s6 (25–37), r2 (35–55), r3 (25–37), r5 (25–37), J1 (25–37), J2 (30–37), J3 (30–37), J4 (30–37), J5 (43–50), Z1 (30–37), Z2 (30–45), Z3 (37–50), S1 (25–30), S3 (25–37), S4 (30–45), S5 (37–50).

Ventral idiosoma ( Fig. 3 ). Base of tritosternum 30–37 long and 15–20 wide, pilose laciniae 90–100 long. A pair of free sclerotised presternal shields present. Sternal shield 125–140 long at mid-line and 95–103 wide at the narrowest point between coxae II, with punctiform reticulation, three pairs of setae (St1–St3) and two pairs of lyrifissures (iv1, iv2). Anterior and posterior margins of sternal shield concave medially. Metasternal shields free, subtriangular, punctate, each with seta St 4 and lyrifissure iv 3. Genital shield 105–120 long and 100–120 wide, truncate posteriorly, with delicate punctiform ornamentation, a pair of genital setae St 5 and four small sclerites close to posterior margin. Genital lyrifissures iv 5 on the soft integument. Ventri-anal shield subcordate, 240–300 long and 210–280 wide, length/width 1.03–1.22, with punctiform reticulation, two pairs of pre-anal setae (Jv1, Jv2), three circum-anal setae, one pair of poroids, and glands gv3. Bases of para-anal setae situated anteriorly of anus. Ventral soft integument with 11 pairs of setae (Jv3-Jv5, Zv2, Zv3, r6, R1, R3-R4, R6-R7) and five pairs of poroids. Area between peritrematal shields and antero-lateral margins of ventri-anal shield with three oblong platelets: two lateral platelets smaller than the medial platelet. Metapodal shields elongate, situated close to anterolateral margins of ventri-anal shield. Surfaces between coxae I and II with three pairs of small podal platelets, each medial platelet with a poroid. Exopodal shields III free, abutting the peritrematal shields and exopodal shields IV. Exopodal shields IV free, each with gland gv2. Peritrematal shields fused with dorsal shield anteriorly, with five pairs of poroids, one pair situated laterally of stigmata is conspicuously enlarged. Peritreme extending anteriorly to enlarged gland gdj 3, near of z1 seta on dorsal shield ( Fig. 2 ). Posterior ends of peritrematal shields slightly widened close to stigmata and extending beyond the posterior margin of coxae IV and exopodals IV. Peritrematal shield is expanded at level of stigmata with vertical sculptural line extending the level of posterior margin of IV exopodal shields. Length of ventral setae: St1 (42–50), St2 (42–50), St3 (37–45), St4 (30–42), St5 (35–40), Jv1 (37–50), Jv2 (50–55), Jv3 (35–40), Jv4 (42–50), Jv5 (52–62), Zv3 (20–25), Zv4 (37–42), para-anal (37–40), post-anal setae (42–50). Length of marginal setae: r6 (18–23), R1 (15–18), R3 (15–30), R4 (33–45), R6 (37–40), R7 (37–40).

Spermatheca. ( Fig. 4 ). Sperm access system typical for genus: spermathecal tubes very long and associated with internal cavity of posterior margin of coxa III, posterior tips slightly widened.

Gnathosoma. Fixed cheliceral digit 62–64 long, with two teeth in addition to apical hook and setiform pilus dentilis ( Fig. 5 ). Movable cheliceral digit 60–62 long, with two teeth in addition to apical hook. Chelicera with dorsal seta, lateral (antiaxial) and dorsal lyrifissures, and setal brush around base of movable digit. Epistome widened basally, distal margin moderately rounded, irregularly finely denticulated ( Fig. 6 ). Deutosternal groove of hypostome with five denticulate rows, each bearing 10–12 denticles, and a smooth basal line ( Fig. 7 ). Seta h3 longer than other (52–62), h1 (25–37), h2 (17–22), pc (25–27). Corniculi 27–29 long and 10 wide, tapered, with compression at inner side. Palp apotele 3-tined.

Legs. Lengths: I 485–570, II 400–475, III 325–365, IV 430–515 µm. Chaetotaxy of legs I–IV: coxae—2 (0 0/ 2 0), 2 (0 0/2 0), 2 (0 0/2 0), 1 (0 0/1 0); trochanters—5 (1 1/2 1), 5 (1 0/3 1), 5 (1 0/3 1), 5 (1 0/3 1); femora—12 (2 5/3 2), 11 (2 5/3 1), 6 (1 3/1 1), 6 (1 3/1 1); genua—12 (2 5/3 2), 11 (2 5/3 1), 8 (2 4/1 1), 8 (2 4/1 1); tibiae—12 (2 5/3 2), 10 (2 4/2 2), 7 (1 2/3 1), 7 (1 3/2 1); tarsi II–IV: 18, 18, 17. Tarsus II with two spur-like setae pl1 and pl2 ( Fig. 8 ). Trochanter I shown in Fig. 9 . All legs with pretarsus, ambulacral stalk, a pair of strongly sclerotised claws and rounded pulvillus with five lobes.

Male ( Figs 10‒13 , 1 specimen measured)

Dorsal idiosoma. Dorsal shield 660 long, 390 wide, length/width 1.69. Chaetotaxy similar to that of female.

Ventral idiosoma ( Fig. 10 ). Base of tritosternum 20 long and 18 wide; laciniae pilose, 85 long. Sternogenital shield with reticulation and punctiform ornamentation, 213 long and 105 wide at the narrowest point between coxae II; with five pairs of acicular setae (St1–St5) and with three pairs of lyrifissures. Genital opening on anterior margin of sternogenital shield. Podal and peritrematal shields as in female. Ventri-anal shield subcordate, with punctiform reticulation, 330 long and 270 wide, length/width 1.22; with four pairs of ventral setae (Jv1–Jv3, Zv3), three circumanal setae, three pairs of poroids and a pair of glands gv3. Soft integument around ventri-anal shield with three pairs of ventral setae (Jv 4, Jv 5, Zv 4) and two pairs of poroids. Lateral margin of soft integument with six pairs of marginal setae (r6, R1, R3, R4, R6 and R7). Length of opisthogastric setae: Jv1 (45), Jv2 (55), Jv3 (37), Jv4 (30), Jv5 (57), Zv3 (25), Zv4 (30), po (55), pa (broken). Length of marginal setae: r6 (20), R1 (17), R3 (22), R4 (35), R6 (43), R7 (40).

Gnathosoma. Fixed digit of chelicera 55 long, with three teeth in addition to apical hook and setiform pilus dentilis ( Fig. 11 ); movable digit 50 long, unidentate, with setal brush at base. Spermatodactyl tubular, curved backward, directed dorsally, narrowed distally, with truncate tip; internal canal along its entire length. Cheliceral dorsal seta, lateral (antiaxial) and dorsal lyrifissures as in female. Corniculi 37 long and 17 wide, almost straight on inner side, and with rounded basal expansion on outer side ( Fig. 12 ). Epistome not visible. Hypostome as in female, length of setae: h 1 (30), h 2 (20), h 3 (50), pc (22).

Legs. Lengths: I—590, II—450, III—375, IV—525. Chaetotaxy of legs I–IV similar to that of female, except tarsus IV with 18 setae (in female, tarsus IV with 17 setae). Trochanter I with five setae as in female (1 1/2 1), one ventral seta absent; femur I with 12 setae (2 5/3 2), one ventral seta absent. Leg II with one ventral large spur-like projection on femur, two small spur-like setae on genu, two small spur-like setae on tibia and two large distal spurlike setae pl1 and pl2 on tarsus ( Fig. 13 ). All legs with pretarsus, ambulacral stalk, a pair strongly sclerotised claws and rounded pulvillus.

Deutonymph ( Figs 14‒16 , 6 specimens measured).

Dorsal idiosoma ( Fig. 14 ). Dorsal shield oval, with fine punctiform reticulation on opisthonotal region, 500–570 long and 260–310 wide (at level of r3 setae), length/width 1.7–1.9, with deep mediolateral incisions. Dorsal shield with 30 pairs of acicular setae. Podonotal region with 18 pairs of setae and six pairs of poroids, including enlarged cavity-like gdj3 and slit-like idj1; two pairs of small dark-coloured spots scarcely distinguishable under dorsal shield cuticle anteriorly. Opisthonotal region with 12 pairs of setae and 13 pairs of poroids. Length of dorsal setae: j1 (18–20), j2 (20–25), j3 (30–32), j4 (25–27), j5 (17–20), j6 (18–20), z1 (5–7), z2 (27–30), z4 (35–37), z5 (17–20), z6 (17–20), s2 (17–20), s4 (25–27), s5 (27–30), s6 (17–20), r2 (18–20), r3 (18–20), r5 (18–20), J1 (18–20), J2 (17–20), J3 (15–17), J4 (17–20), J5 (37–40), Z1 (25–27), J2 (17–20), Z2 (25–27), Z3 (30–32), S1 (17–20), S3 (17–20), S4 (30–32), S5 (35–37). Total number of dorsal setae—36 pairs, including marginal setae of r -R rows, inserted latero-ventrally.

Ventral idiosoma ( Fig. 15 ). One pair of presternal shields present. Sternal shield 225–240 long and 110–120 wide at the level of St2 setae; with four pairs of setae (St1–St4) and three pairs of lyrifissures, setae St5 on soft cuticle outside the shield. Anal shield with slight linear reticulation, 105–145 long and 80–100 wide, with three circum-anal setae and a pair of gland pores gv3. Two pairs of endopodal shields between coxae II–III and III–IV present, free from sternal shield. Exopodal shields III and IV developed. Metapodal shields placed between coxae IV and anal shield. Seven pairs of setae located on soft integument (Jv1-Jv5, Zv3-Zv4) and six pairs of setae inserted along the margin (r6, R1, R3, R4, R 6 and R7). Peritrematal shield developed only in anterior part of peritreme, not connected with dorsal shield. Peritremes long, reaching the level of pores gdj 3 on dorsal side of idiosoma. Stigmata situated at the level between coxae III–IV. Three pairs of peritrematal poroids distinct: one enlarged pair laterad to stigmata and two smaller between stigmata and metapodal shield. Length of ventral setae: St1 (22–25), St2 (22–25), St3 (22–25), St4 (20–22), St5 (20–22), Jv1 (22–25), Jv2 (22–25), Jv3 (22–25), Jv4 (30–32), Jv5 (47–50), Zv3 (20–25), Zv4 (37–40), pa (30–32), po (35–37), r6 (22–25), R1 (18–20), R3 (18–20), R4 (22–25), R6 (37–40), R7 (37–40).

Gnathosoma. As in the adults.

Legs. Lengths: I—405–425, II—285–300, III—265–275, IV—365–375. Chaetotaxy of legs I–IV as in male, tarsus IV with 18 setae. Reductions in leg chaetotaxy as in adults: trochanter I with five setae (1 1/2 1); femur I with 12 setae (2 5/3 2). Tarsus II with two spur-like setae pl 1 and pl 2 ( Fig. 16 ).

Protonymph ( Figs 17–20 , 1 specimen measured).

Dorsal idiosoma ( Fig. 17 ). Dorsal idiosoma 450 long and 260 wide at the widest point, with weakly sclerotised podonotal and opisthonotal shields. Podonotal shield with 11 pairs of acicular setae (j1‒j6, z2, z4, z5, s4, s5) and five pairs of poroids. Opisthonotal shield with ten pairs of acicular setae (J1‒J5, Z1‒Z3, S4 and S5) and 11 pairs of poroids. Six pairs of acicular setae and one pair of poroids inserted on marginal soft cuticle: s2, s6, r3, r5, z6 and S3. Length of dorsal setae: j1 (22), j2 (25), j3 (25), j4 (25), j5 (20), j6 (25), z2 (27), z4 (25), z5 (20), z6 (25), s2 (32), s4 (25), s5 (25), s6 (25), r3 (32), r5 (25), J1 (17), J2 (17), J3 (17), J4 (30), J5 (67), Z1 (25), Z2 (37), Z3 (62), S3 (37), S4 (37), S5 (75). Total number of dorsal setae—27 pairs.

Ventral idiosoma ( Fig. 18 ). Presternal shields absent. Tritosternum as in deutonymph and adults. Sternal shield 160 long and 105 wide, weakly sclerotised, with indistinct margins, three pairs of setae (St1-St3) and two pairs of lyrifissures. Peritrematal shields represented by three pairs of rudimentary fragments: two anterior fragments on lateral margins of podonotal region and a third around the short reduced, periterme. Coxae IV with weakly sclerotised margins in endo-parapodal area. One pair of small and suboval metapodal shields present. Two pairs of poroids present between peritremes and metapodal shields. Ventral soft integument with four pairs of acicular setae, three short, 20 µm long, Jv 5 longest, 60 µm in length. Anal shield oval, 87 long and 70 wide, with a pair of para-anal setae (25), postanal seta (30) and a pair of gv 3 glands at posterolateral margins.

Gnathosoma. Gnathosoma with four pairs of hypostomal setae, h 3 longest. Deutosternal groove with five denticulate rows. Corniculi well sclerotised, small and narrow ( Fig. 19 ).

Legs. Lengths: I—400, II—300, III—260, IV—330. Chaetotaxy of legs I–IV: coxa—2, 2, 2, 1; trochanter—4 (1 0/2 1), 4 (1 0/2 1), 4 (1 0/2 1), 4 (1 0/2 1); femur—10 (2 4/2 2), 8 (1 4/2 1), 5 (1 3/1 0), 4 (1 3/0 0); genu—8 (1 4/ 2 1), 6 (1 4/0 1), 6 (1 4/0 1), 5 (1 4/0 0); tibia—8 (1 4/2 1), 7 (1 3/2 1), 7 (1 3/2 1), 7 (1 3/2 1). Tarsus II–IV: 17, 17, 17. Tarsus II with two spur-like setae pl 1 and pl 2 ( Fig. 20 ).

Material examined. Holotype female, Russia, South Siberia, North Altai Mts., Altaiskoe District, environs of Basargino Village (51̊44́N, 85 ̊25́E, 700 m a.s.l.), forest with Betula pubescens and Populus tremula , in litter, 13 July, 2011, coll. I. Marchenko. Paratypes — 2 females, 1 deutonymph, same data as in holotype; NORTH ALTAI: 2 females, Shebalino District, environs of Ilyinka Village (51̊27́N, 85 ̊07́E, 1100 m a.s.l.), Gladkih Mts., mixed forest, in litter, 19 July, 2011, coll. I. Marchenko; 1 female, Shebalino District, environs of Cherga Village (51 ̊31 N, 85 ̊34́E, 500 m a.s.l.), Sema River floodplain forest with Betula and Salix spp., in litter, 16 July, 2011, coll. I. Marchenko; 1 female, Cherga Village (51 ̊34 ́N, 85 ̊34 ́E, 470 m a.s.l.), in the village, in soil, 15 July, 2011, coll. I. Marchenko; 1 female, 2 deutonymphs, 1 protonymph, Shebalino District, Cherginsky Ridge, Belok Mukhor- Cherga Mts., (51 ̊21́N, 85 ̊19́E, 1100‒1850 m a.s.l.), coniferous forest with Larix sibirica and Pinus sibirica and alpine tundra, in litter and soil, 21 July, 2011, coll. I. Marchenko and N. Vladimirova; NORTHEAST ALTAI: 1 female, Turochak District, environs of Kebezen Village (51 ̊55́N, 87 ̊06́E, 500 m a.s.l.), coniferous forest with Pinus sylvestris , in soil, 22 June, 2007, coll. I. Marchenko; CENTRAL ALTAI: 2 females, Ulagan District, environs of Aktasch Village, Kurai Ridge Mts. (50 ̊18́N, 87 ̊36́E, 2500 m a.s.l.), alpine tundra, in soil, 22 July, 1964, coll. S. Stebaeva, 1 female, 29 June 2008, coll. I. Marchenko; 7 females, 2 deutonymphs, Ongudai District, environs of Kulady Village (50 ̊41 ́N, 85 ̊46 ́E), coniferous forest with Larix sibirica , Pinus sibirica and Picea obovata , on the northern slope, and Larix sibirica forest on the southern slope, in litter, 7‒ 8 August, 2008, coll. I. Marchenko; WEST SAYAN, TUVA: 1 female, Kaa-Khem District, left riverside of Malyi Enisei River (Tuvan name—Kaa-Khem), environs of Derzig-Aksy Village (also known as Danilovka Village) (51 ̊27́N, 95 ̊36́E), 8 June, 1976, coll. L. Grishina; 2 females, Tandinsky District, slope of Eastern Tannu-Ola Ridge, environs of Berezovka Village (50 ̊55 ́N, 95 ̊13 ́E), 13 and 31 July, 1976, coll. O. Belova; EAST SAYAN: 1 female, 1 male, environs of Krasnoyarsk City, Stolby Nature Reserve (55 ̊57́N, 92 ̊46 ́E), in litter, 14 September, 1972, coll. L. Grishina.

Holotype and paratypes are deposited in Zoological Museum of Institute of Systematics and Ecology of Animals, Novosibirsk, Russia; some paratypes (seven females, two deutonymphs and one protonymph) are kept in arthropod collection of Manchester Museum, United Kingdom.

Etymology. The species is dedicated to Russian ornithologist Yuri A. Anisimov of Baikal Nature Reserve, who has helped in the organisation of field collections of mites in East Sayan Mountains in 2014.

Remarks. Pachyseius anisimovi sp. nov. is most similar to two Asian species: P. orientalis and P. siranensis , but it differs from both of them having ventral soft integument with 11 pairs of setae: six pairs of marginal setae and five pairs of ventral setae; tarsus II with two spur-like setae. Pachyseius anisimovi sp.nov. is remarkable in having reduced chaetotaxy on trochanter I, femur I and in females—tarsus IV. In all examined specimens of adults trochanter I has five setae (1 1/2 1)—typically six; femur I has 12 setae—typically 13. In the female tarsus IV has 17 setae—typically 18. The only examined male specimen has 18 setae tarsus IV.

Figures

FIGURES 1 ‒ 4. Pachyseius anisimovi sp. nov., female. 1. Dorsal idiosoma; 2. Anterior part of dorsal shield; 3. Ventral idiosoma; 4. coxa III with sperm acces structures.

FIGURES 5 ‒ 9. Pachyseius anisimovi sp. nov., female. 5. Chelicera; 6. Epistome; 7. Ventral gnathosome; 8. Tarsus II; 9. Trochanter I.

FIGURES 10 ‒ 13. Pachyseius anisimovi sp. nov., male. 10. Ventral idiosoma; 11. Chelicera; 12. Anteroventral hypostome with corniculi; 13. Leg II.

FIGURES 14 ‒ 16. Pachyseius anisimovi sp. nov., deutonymph. 14. Dorsal idiosoma; 15. Ventral idiosoma; 16. Tarsus II.

FIGURES 17 ‒ 20. Pachyseius anisimovi sp. nov., protonymph. 17. Dorsal idiosoma; 18. Ventral idiosoma; 19. Corniculi; 20. Tarsus II.