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# First description of phoretic and redescription of non-phoretic females of Pediculaster nidicolus (Mahunka) (Acari: Pygmephoridae) from Western Siberia, Russia

Alexander Khaustov

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Alexander Khaustov. First description of phoretic and redescription of non-phoretic females of Pediculaster nidicolus (Mahunka) (Acari: Pygmephoridae) from Western Siberia, Russia. Acarologia, 2022, 62 (2), pp.359-377. 10.24349/zk54-xqx6. hal-03627629

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# First description of phoretic and redescription of non-phoretic females of *Pediculaster nidicolus* (Mahunka) (Acari: Pygmephoridae) from Western Siberia, Russia

Alexander A. Khaustovª

ªTyumen State University, Tyumen, Volodarskogo 6, 625003 Russia.

## Original research

### ABSTRACT

Phoretic and non-phoretic females of *Pediculaster nidicolus* (Mahunka) (Acari: Pygmephoridae) are recorded from Russia for the first time. Mites were collected from the nest of undetermined small mammal in Western Siberia, Russia. Non-phoretic female is redescribed, and phoretic female is described for the first time. An updated key to phoretic females of Palaearctic *Pediculaster* species is provided.

**Keywords** Pygmephozoidea; systematics; morphology; female dimorphism; Tyumen Region

**Zoobank** http://zoobank.org/022BDC53-CB93-4CFF-BA55-1DE9153AD7CA

### Introduction

The genus *Pediculaster* Vitzthum, 1931 (Acari: Pygmephozoidea) is the largest in the family Pygmephoridae and comprises more than 100 described species in the world fauna (Khaustov 2020; Seyedein *et al.* 2021). Mites of the genus *Pediculaster* are fungivorous and inhabit a great variety of habitats, e.g. soil, litter, mosses, dung, nest material, decaying organic matter (Camerik and Kheradmand 2010). Some species are considered as pests of mushrooms in commercial mushroom-houses (Cross and Kaliszewski 1988). *Pediculaster*-mites are characterized by the presence of two morphologically different forms of females: non-phoretic or “normal” and phoretic (Martin 1978; Camerik *et al.* 2006). For most species of *Pediculaster* non-phoretic females still unknown. At the same time, some species were described based only on non-phoretic females. Until now eight species of *Pediculaster* have been reported from Western Siberia, namely: *P. bisetus* Khaustov, 2020, *P. camerikae* Khaustov, 2008b, *P. dudinskii* Khaustov, 2011, *P. ermilovi* Khaustov, 2015, *P. lignarius* Khaustov, 2015, *P. montanus* Khaustov, 2008b, *P. rarus* Khaustov, 2020, and *P. tjumeniensis* Khaustov, 2020 (Khaustov 2015, 2020).

Non-phoretic females of *Pediculaster nidicolus* (Mahunka, 1972) were described from the nest of mole (*Talpa europaea*) from Austria (Mahunka 1972). Later it was also recorded from Slovenia (Mahunka 1975). Phoretic female of this species were unknown up till now.

During the study of heterostigmatic mites of Western Siberia, I found numerous specimens of phoretic and non-phoretic females of *Pediculaster nidicolus* from the nest of undetermined small mammal. The main goal of this paper is to redescribe non-phoretic and describe phoretic females of *Pediculaster nidicolus* based on material from Western Siberia.

Received 03 February 2022

Accepted 24 March 2022

Published 28 March 2022

Corresponding author

Alexander A. Khaustov:
alex1973khaustov@gmail.com

Academic editor
Auger, Philippe

https://doi.org/
10.24349/zk54-xqx6

ISSN 0044-586X (print)

ISSN 2107-7207 (electronic)

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Khaustov A. A.

Licensed under
Creative Commons CC-BY 4.0

OPEN ACCESS
**Material and methods**

The mites were collected from sample of small mammal nest using Berlese funnels and mounted in Hoyer's medium. Numerous phoretic females were attached to various insects (rove beetles, insect larvae) and bigger mites (Figs 9A, B). The terminology of the idiosoma and legs follows that of Lindquist (1986); the nomenclature of subcapitular setae and the designation of cheliceral setae follow those of Grandjean (1944, 1947), respectively. The systematics of Pygmephoroidea follows that of Khaustov (2004, 2008a). All measurements are given in micrometers (µm). For leg chaetotaxy, the number of solenidia is given in parentheses. Mite morphology was studied using a Carl Zeiss AxioImager A2 compound microscope with phase contrast and differential-interference contrast (DIC) illumination. Photomicrographs were taken with a digital camera AxioCam ICc5 (Carl Zeiss, Germany). For SEM microscopy, alcohol-preserved mites were dried in a freeze drying device JFD 320 (JEOL, Japan), dusted with gold and scanned with the aid of a JEOL-JSM-6510LV SEM microscope.

Abbreviations: ap1-ap5 - apodemes 1-5, appr - prosternal apodeme, appo - poststernal apodeme, apsej - sejugal apodeme, Tr - trochanter, Fe - femur, Ge - genu, Ti - tibia, Ta - tarsus, TiTa - tibiotarsus, ass - accessory setogenous structure, php 1-3 - pharyngeal pumps 1-3.

**Systematics**

**Family Pygmephoridae Cross, 1965**

**Genus Pediculaster Vitzthum, 1931**

Type species: *Pygmephorus mesembrinae* Canestrini, 1881, by original designation.

**Pediculaster nidicolus (Mahunka, 1972)**

*Siteroptes nidicolus* Mahunka, 1972, 58

*Siteroptes* (*Siteroptoides*) *nidicolus*: Martin 1978, 125

*Pediculaster nidicolus*: Mahunka 1979, 133

(Figs 1–10)

**Redescription of non-phoretic female**

(Figs 1–4)

Length of idiosoma 255–315, width 130–160.

*Idiosomal dorsum* (Fig. 1A). All dorsal shields with numerous small round puncta. Stigmata small, oval, one-chambered and associated with long tracheal trunks. Setae *h2* pointed and smooth, other dorsal setae blunt-tipped and barbed; trichobothria *sc1* short, spherical. Cupuli *ia* on tergite D and *ih* on tergite H very small, round. Setae *v1* situated distinctly anteriad *v2*. Lengths of dorsal setae: *v1* 27–33, *v2* 22–25, *sc2* 55–64, *c1* 42–48, *c2* 55–63, *d* 47–60, *e* 26–30, *f* 48–59, *h1* 45–53, *h2* 11–14. Distances between setae: *v1–v1* 8–9, *v2–v2* 30–36, *sc2–sc2* 30–40, *c1–c1* 44–55, *c1–c2* 25–30, *d–d* 66–76, *e–f* 13–14, *f–f* 51–61, *h1–h1* 36–46, *h1–h2* 17–19.

*Idiosomal venter* (Fig. 1B). Ventral plates with numerous small round puncta. Sternocoxal fields I and II with three pairs of setae each. Setae *1c*, *2b*, *3c* and *4c* usually pointed; other ventral setae blunt-tipped; setae *1c*, *ps1* and *ps2* smooth, other ventral setae weakly barbed; setae *2a* subequal with *2b*; setae *ps3* much longer than *ps1-2*. Ap1, ap2 and apsej well developed and joined with appr; ap3, ap4 and ap5 well developed and joined with appo. Posterior margin of poststernal plate almost straight, without median lobe. Only one horn-shaped genital sclerite clearly visible. Lengths of ventral setae: *1a* 13–17, *1b* 18–23, *1c* 17–19, *2a* 14–18, *2b* 15–21, *2c* 16–18, *3a* 17–19, *3b* 15–18, *3c* 20–22, *4a* 14–18, *4b* 17–19, *4c* 18–21, *ps1* 7–8, *ps2* 8–11, *ps3* 27–30.
<figure><img src="image_9.png" /><figcaption>**Figure 1** *Pediculaster nidicolus* (Mahunka, 1972), non-phoretic female: A – dorsum of body, B – venter of body. Legs omitted.</figcaption></figure>
<figure><img src="image_10.png" /><figcaption>**Figure 2** *Pediculaster nidicolus* (Mahunka, 1972), non-phoretic female: A – gnathosoma, dorsal aspect, B – gnathosoma and pharyngeal pumps, ventral aspect.</figcaption></figure>

*Gnathosoma* (Fig. 2). Length of gnathosomal capsule 26–30, width 27–31. Dorsal median apodeme weakly developed. All gnathosomal setae pointed; setae *cha* and *chb* weakly barbed, other gnathosomal setae smooth. Palp tibiotarsus with well-developed blunt-tipped claw and tiny eupathid-like seta; palps with well-developed solenidion and mushroom-shaped accessory setigenous structure ventrally. Hp 1 small, bow-shaped, located outside gnathosomal capsule; hp 2 and 3 oval (Fig. 2B), situated close to each other on long oesophagus and far from hp
<figure><img src="image_11.png" /><figcaption>**Figure 3** *Pediculaster nidicolus* (Mahunka, 1972), non-phoretic female: A – left leg I, dorsal aspect, B – left leg II, dorsal aspect.</figcaption></figure>

1. Lengths of gnathosomal setae: cha 12–13, chb 14–18, dFe 11–12, dGe 13–16, m 14–17. Palpcoxal (postpalpal) setae and pits m absent.

*Legs* (Figs 3, 4). Leg I (Fig. 3A). Setation: Tr 1 (v'), Fe 4 (d, l', l'', v''), Ge 4 (l', l'', v', v''), Ti 6(2) (d, l', l'', v', v'', k, φ1, φ2), Ta 13(2) (pl', pl'', p', p'', tc', tc'', ft', ft'', s, pv', pv'', u', u'', ω1, ω2). Tarsus with simple hooked claw. Lengths of solenidia ω1 15–17, ω2 7–8, φ1 8–9, φ2 7–9; solenidion ω1 digitiform, solenidion φ1 slightly clavate, other solenidia baculiform. Setae (p), (tc) and (ft) eupathid-like, smooth and weakly blunt-tipped; seta k of tibia smooth and weakly blunt-tipped; other leg setae pointed and barbed, sometimes seta v' of trochanter smooth. Leg II (Fig. 3B). Setation: Tr 1 (v'), Fe 3 (d, l', v''), Ge 3 (l', l'', v'), Ti 4(1) (d, l', v', v'', φ), Ta 7(1) (pl'', tc', tc'', pv', pv'', u', u'', ω). Solenidion ω 10–12 digitiform, solenidion φ 4–5 erect, baculiform. Tarsal claws simple, hooked; empodium short and wide, flipper-like. All leg setae barbed; setae d and l' of femur blunt-tipped, other leg setae pointed. Leg III (Fig. 4A).
<figure><img src="image_12.png" /><figcaption>**Figure 5** *Pediculaster nidicolus* (Mahunka, 1972), phoretic female: A – dorsum of body, B – venter of body. Legs omitted.</figcaption></figure>
<figure><img src="image_13.png" /><figcaption>**Figure 6** *Pediculaster nidicolus* (Mahunka, 1972), phoretic female: A – left leg I, dorsal aspect, B – left leg II, dorsal aspect.</figcaption></figure>

*Idiosomal dorsum* (Figs 5A, 8A, 9C, D) as in phoretic female, but dorsal setae usually longer and puncta on dorsal shields slightly bigger. Setae *v1* and *v2* situated in one transverse row. Prodorsum anterolaterally with pocket-like depressions (Fig. 9C). Lengths of dorsal setae: *v1* 35–41, *v2* 32–35, *sc2* 67–69, *c1* 57–71, *c2* 69–81, *d* 59–73, *e* 39–50, *f* 66–77, *h1* 55–69, *h2* 12–16. Distances between setae: *v1–v1* 10–12, *v2–v2* 26–28, *sc2–sc2* 30–36, *c1–c1* 42–46, *c1–c2* 29–33, *d–d* 70–77, *e–f* 14–22, *f–f* 56–62, *h1–h1* 37–47, *h1–h2* 19–23.

*Idiosomal venter* (Figs 5B, 8B, 9E, F, 10B, C) similar to that of non-phoretic female, but plates sclerotized stronger, setae usually longer, ap5 sclerotized weaker and usually not extending beyond bases of setae 4a and puncta on ventral plates bigger. Setae *1b*, *2c*, and *ps1-3* weakly blunt-tipped, other ventral setae pointed; in some specimens setae *1a*, *2a* and *3a* weakly blunt-tipped. Lengths of ventral setae: *1a* 22–28, *1b* 28–31, *1c* 23–26, *2a* 23–31, *2b* 27–30, *2c* 23–26, *3a* 22–29, *3b* 24–29, *3c* 26–34, *4a* 24–33, *4b* 28–38, *4c* 28–32, *ps1* 8–11, *ps2* 9–11, *ps3* 31–35.

*Gnathosoma* (Fig. 10A). Length of gnathosomal capsule 25–29, width 27–31. Gnathosoma and pharyngeal pumps as in non-phoretic female. Lengths of gnathosomal setae: *cha* 14–18, *chb* 16–23, *dFe* 12–14, *dGe* 15–17, *m* 16–18.

*Legs* (Figs 6, 7, 10D–F). Leg I (Figs 6A, 10E, F). Tibia and tarsus fused into massive ovate tibiotarsus. Tarsal claw thicker than in non-phoretic female; Unguinal setae fused into subtriangular structure opposing to claw. Seta *d* of femur spatulate; setae (*l*) of genu, *k*, (*p*), (*tc*), and (*ft*) of tibiotarsus blunt-tipped, other leg setae pointed; setae *l'* of femur, *pl'*, *k*, (*p*), (*tc*), and (*ft*) of tibiotarsus smooth, other leg setae barbed. Leg setation: Tr 1 (*v*'), Fe 4 (*d*, *l'*, *l''*, *v''*),
<figure><img src="image_14.png" /><figcaption>**Figure 7** *Pediculaster nidicolus* (Mahunka, 1972), phoretic female: A – left leg III, dorsal aspect, B – left leg IV, dorsal aspect.</figcaption></figure>

Ge 4 (*l*, *l'', *v*, *v''*), TiTa 17(4) (*d*, *l*, *l'', *v*, *v''*, *k*, *pl*, *pl'', *p*, *p'', *tc*, *tc'', *ft*, *ft'', *s*, *pv*, *pv'', *φ*1, *φ*2, *ω*1, *ω*2). Lengths of solenidia *ω*1 15–17, *ω*2 7–9, *φ*1 9–11, *φ*2 7–9; shape of solenidia as in non-phoretic female. Leg II (Figs 6B, 10D). Leg setation: Tr 1 (*v*'), Fe 3 (*d*, *l', *v''*), Ge 3 (*l', *l'', *v*'), Ti 4(1) (*d*, *l', *v', *v'', *φ*), Ta 6(1) (*pl'', *tc*, *tc'', *pv*, *pv'', *u*', *ω*). Solenidion *ω* 9–11 digitiform; solenidion *φ* 4–5 weakly clavate, situated in deep depression and only distal half visible (Fig. 10D). Tarsal claws thickened basally; empodium long and narrow. All leg setae barbed; setae *d* of femur and *u'* of tarsus blunt-tipped, other leg setae pointed. Leg III (Fig. 7A). Leg setation: Tr 1 (*v*'), F2 3 (*d*, *v*'), Ge 2 (*l', *v*'), Ti 4(1) (*d*, *l', *v', *v'', *φ*), Ta 6 (*pl'', *tc*, *tc'', *pv*, *pv'', *u*'). Claws, empodium and solenidion *φ* 4 as on tarsus II. All leg setae barbed; setae *d*, *v'* of femur, *l'* of genu, and *u'* of tarsus blunt-tipped, other leg setae pointed. Leg IV (Fig. 7B). Leg setation: Tr 1 (*v*'), Fe 2 (*d*, *v*'), Ge 1 (*v*'), Ti 4(1) (*d*, *l', *v', *v'', *φ*), Ta 6 (*pl'', *tc*, *tc'', *pv*,
<figure><img src="image_15.png" /><figcaption>**Figure 8** Phase contrast micrograph of *Pediculaster nidicolus* (Mahunka, 1972), phoretic female: A – general view dorsally, B – general view ventrally.</figcaption></figure>

*pv''*, *u'*). Empodium as on tarsi II and III; claws simple, hooked. Solenidion φ 3–4 situated in deep depression with terminal pore. All leg setae barbed; setae *v'* of trochanter, *d*, *v'* of femur, and *d* of tibia blunt-tipped, other leg setae pointed.

Larva and male unknown.

**Material examined**

Sixteen phoretic and seven non-phoretic females, Russia, city of Tyumen, Gagarin park, in nest of undetermined small mammal, 57°10′17.0″N 65°36′25.1″E, 10 October 2021, coll. A.A. Khaustov.

**Material deposition**

All examined materials are deposited in the mite collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.

**Remarks**

Non-phoretic females of *Pediculaster nidicolus* are completely congruent with original description and undoubtedly conspecific with specimens from Austria. Phoretic females are very similar to *P. altaicus* Mahunka, 1969, described from the nest of *Microtus* sp. from Mongolia (Mahunka 1969). However, based on original description, *P. altaicus* has longer dorsal hysterosomal setae. For example, setae *c2* are longer than distance between their bases
<figure><img src="image_16.png" /><figcaption>**Figure 9** SEM micrographs of *Pediculaster nidicolus* (Mahunka, 1972), phoretic female: A – several females attached to gamasid mite *Haemogamasus ambulans* (Haemogamasidae), B – one female attached to *Haemogamasus ambulans*, C – general view dorsally, D – prodorsum, E – general view ventrally, F – prosoma, ventral aspect.</figcaption></figure>
<figure><img src="image_17.png" /><figcaption>**Figure 10** SEM micrographs of *Pediculaster nidicolus* (Mahunka, 1972), phoretic female: A – gnathosoma, B – metapodosoma, ventral aspect, C – opisthosoma, ventral aspect, D – tibia and tarsus II, dorsal aspect, E – tibiotarsus I, dorsal aspect, F – tibiotarsus I, ventral aspect.</figcaption></figure>
(clearly shorter in *P. nidicolus*). However, the length of dorsal setae is highly variable in *Pediculaster* species and it could be a result of intraspecific variability. Potentially *P. nidicolus* could be a junior synonym of *P. altaicus*. The comparison of phoretic females of *P. nidicolus* with the type material of *P. altaicus* is necessary for the final clarification of the synonymy of these species.

*Pediculaster nidicolus* is recorded from Russia for the first time.

## Key to phoretic females of *Pediculaster* of Palaearctic

Modified from Khaustov 2015; *P. egypticus* Omar, 2014, *P. gallinae* Zacher and Kandeel, 1986 and *P. arabicus* Zacher and Kandeel, 1986 are not included because of incomplete description; *P. limosinae* Samšińak, 1984, *P. incompletus* Samšińak, 1984 and *P. kaszabi* Mahunka, 1970a not included as suspected synonyms of *P. sellickianus*, *P. morelliae* and *P. dominguesi*, respectively.

<table><tbody><tr><td>1.</td><td>Coxisternal fields I with two pairs of setae (Ic absent)</td><td>2</td></tr><tr><td>—</td><td>Coxisternal fields I with three pairs of setae</td><td>5</td></tr><tr><td>2.</td><td>Ap5 well-developed</td><td>3</td></tr><tr><td>—</td><td>Ap5 absent</td><td>P. minagarici Gao and Zou, 2000</td></tr><tr><td>3.</td><td>Dorsal hysterosomal setae relatively short: setae d distinctly shorter than distance d-d</td><td>4</td></tr><tr><td>—</td><td>Dorsal hysterosomal setae very long: setae d distinctly longer than distance d-d</td><td>P. arcanus (Rack, 1967)</td></tr><tr><td>4.</td><td>Setae e and h2 subequal, setae v1 more than three times longer than v2</td><td>P. subarcanus Gao and Zou, 2000</td></tr><tr><td>—</td><td>Setae e about three times longer than h2, setae v1 less than two times longer than v2</td><td>P. ermilovi Khaustov, 2015</td></tr><tr><td>5.</td><td>Setae (u) of tibiotarsus I fused together forming structure opposing to tarsal claw</td><td>6</td></tr><tr><td>—</td><td>Setae (u) of tibiotarsus I separated, spine-like</td><td>P. amerahae Sevastianov and Abo-Korah, 1984</td></tr><tr><td>6.</td><td>Coxisternal fields II with two pairs of setae</td><td>7</td></tr><tr><td>—</td><td>Coxisternal fields II with three pairs of setae</td><td>15</td></tr><tr><td>7.</td><td>Setae e present</td><td>8</td></tr><tr><td>—</td><td>Setae e absent</td><td>P. absentia Rahiminejad and Seyedein, 2021</td></tr><tr><td>8.</td><td>Setae h2 shorter than h1</td><td>9</td></tr><tr><td>—</td><td>Setae h2 about two times longer than h1</td><td>P. manicatus (Berlese, 1904)</td></tr><tr><td>9.</td><td>Setae v1 and v2 subequal</td><td>10</td></tr><tr><td>—</td><td>Setae v1 longer than v2</td><td>12</td></tr><tr><td>10.</td><td>Stigmata two-chambered, trochanter IV with seta v'</td><td>11</td></tr><tr><td>—</td><td>Stigmata one-chambered, trochanter IV without seta v'</td><td>P. bisetus Khaustov, 2020</td></tr><tr><td>11.</td><td>Ap5 long, reaching almost to bases of setae 4b, setae e about five times longer than h2</td><td>P. athiasae (Wicht, 1970)</td></tr><tr><td>—</td><td>Ap5 short, reaching to bases of setae 4a, setae e about three times longer than h2</td><td>P. sterculinicola Sevastianov, 1981</td></tr></tbody></table>
42. Setae *ps1* and *ps3* subequal, tibiotarsus I about three times longer than its width
* Setae *ps1* longer than *ps3*, tibiotarsus I about 1.5 times longer than its width
* P. camerikae Khaustov, 2008b
* P. eccoptomeralis Camerik, 2010

43. Solenidion φ1 situated laterally between bases of setae *pl*" and *l"*
* Solenidion φ1 situated close to solenidion φ2 or ω1
44
47

44. Setae *c1* shorter or subequal to *d*
* Setae *c1* longer than *d*
* P. confusus Khaustov, 2008b

45. Ap5 absent
* Ap5 present
* P. ghilarovi Sevastianov, 1988

46. Setae *c1* subequal to distance *c1–c1*, setae *c2* distinctly longer than *d*
* Setae *c1* distinctly longer than distance *c1–c1*, setae *c2* subequal to *d*
* P. amuriensis Sevastianov, Chydyrov and Marroch, 1994

47. Setae *ps3* distinctly longer than *ps1*
* Setae *ps3* shorter or subequal to *ps1*
48
49

48. Stigmata one-chambered
* Stigmata two-chambered
* P. montanus Khaustov, 2008b
* P. zacheri Sevastianov and Abo-Korah, 1984

49. Ap5 present
* Ap5 absent
50
52

50. Setae *e* at least half of length of setae *f*
* Setae *e* shorter than half of length of setae *f*
* P. helomyzalis Camerik, 2006

51. Setae of posterior sternal plate smooth
* Setae of posterior sternal plate barbed
* P. jaltensis Sevastianov, 1974
* P. dominguesi (Athias-Henriot, 1961)

52. Stigmata two-chambered
* Stigmata one-chambered
53
55

53. Setae *e* longer and thicker than *h2*
* Setae *e* and *h2* of similar width and length
* P. martyani Khaustov, 2008b

54. Setae *e* only slightly shorter than *f*
* Setae *e* about two times shorter than *f*
* P. moravicus Samšińak, 1984
* P. pseudomanicatus Camerik, 2001

55. Setae *e* at least two times longer than *h2*
* Setae *e* less than two times longer than *h2*
56
60

56. Setae *c2* no shorter than *c1*
* Setae *c2* shorter than *c1*
* P. collinellularis Camerik, 2006

57. Distance *e–f* less than half of distance *f–f*
* Distance *e–f* at least half of distance *f–f*
* P. gautengensis Camerilk, 1996
58. Dorsal hysterosomal setae relatively long, setae c1 shorter than c2..................59
— Dorsal hysterosomal setae relatively short, setae c1 and c2 subequal ....................
.................................................................................. P. bureschi (Savulkina, 1978)

59. Setae *f* about two times longer than *e* .................... P. horricomus (Savulkina, 1978)
— Setae *f* no more 1/3 longer than *e* .......................... P. microsaniae (Martin, 1978)

60. Setae *e* situated slightly posteriad bases of setae *f* .................................... 61
— Setae *e* situated distinctly anteriad bases of setae *f* ............ P. lignarius Khaustov, 2015

61. Setae *c1* subequal or longer than distance *c1–c1* .................................... 62
— Setae *c1* shorter than distance *c1–c1* .................... P. mesembrinae (Canestrini, 1881)

62. Setae *f* more than four times longer than *e* ............................................ 63
— Setae *f* no more than three times longer than *e* .................... P. rysanovi Samšińak, 1989

63. Setae *tc*" of tarsus IV very long, whip-like, distinctly longer than combined length of genu, tibia and tarsus IV....................................P. koreensis (Mahunka and Rack, 1977)
— Setae *tc*" of tarsus IV distinctly shorter than combined length of genu, tibia and tarsus IV..
.................................................................................. P. perottii Camerik and Coetzee, 1998

## Acknowledgements

The author thank to Alexey Gubin (Tyumen State University, Russia) for the preparation of SEM photos. The research was supported by the cooperative agreement No. FEWZ-2021-0004, funded by the Russian Ministry of Science and Higher Education.

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