Contribution to the fauna of Tydeidae (Acari: Prostigmata) from Western Siberia, Russia

The fauna of Tydeidae of Western Siberia is reviewed. A total of 27 species from eight genera were found in Tyumen and Kurgan Regions. Two species, Lorryia sibiriensis n. sp. and L. speciosa n. sp. are described as new for science; Lorryia evansi Baker is recorded from Russia for the first time and redescribed based on materials from Tyumen Region; Lorryia paravarsoviensis (Momen and Lundqvist), L. subularoides Kaźmierski, L. arkadiensis Panou and Emmanouel, L. argutus (Kuznetsov and Petrov) n. comb., L. serpettae (Momen and Lundqvist) n. comb., L. szeptyckii (Kaźmierski) n. comb., L. filiformis (Momen and Lundqvist), L. grandiinsignia Kaźmierski, Nudilorryia obsequens Kaźmierski, Paralorryia formosa (André), Calotydeus edwardbakeri (Kaźmierski), Tydeus nieuwkerkeni André, T. spathulatus Oudemans and Metalorryia delicata (Kuznetsov) are recorded in Russia for the first time. After examination of the holotype of Paralorryia formosaLivshitz this species is moved toNudilorryia. Morphological characters separating two closely related species, Lorryia catenulata (Thor) and L. polita Kuznetsov, are also provided.


Introduction
The family Tydeidae is a diverse group of mites distributed worldwide and currently includes about 31 genera and more than 300 species (Silva et al. 2016; Kaźmierski et al. 2018; André 2021; Khaustov 2022).Most tydeid mites are fungivorous, however some species are predators of small arthropods, phytophagous and scavengers (Walter et al. 2009).The scientific history of tydeid mites and current state of knowledge in taxonomy are discussed in Kaźmierski (1998), Silva et al. (2016) and André (2021).The tydeid mites of Asian Russia are almost completely unstudied with only two papers describing three new species of Lorryia sensu Kaźmierski, 1989 (Kaźmierski 2008) and a new genus and species, Andrelorryia hajiqanbari Khaustov, 2022(Khaustov 2022).In addition, Kaźmierski (2000) reported Lorryia woolleyi and L. maga from Tuva Republic in Russia.
This study provides a review of Tydeidae collected in Tyumen and Kurgan Regions of Western Siberia, Russia.

Material and methods
Mites were extracted from various samples (soil, litter, bark of trees, etc.) using Berlese funnels.All mites were mounted in Hoyer's medium.Mite morphology was studied using a Carl Zeiss AxioImager A2 compound microscope with phase contrast and differential interference contrast (DIC) illumination.Notation applied to the body and leg setae follow the system of Grandjean, overviewed by Kethley (1990) and André (1981b), respectively; palpal setation follows André (1981a).The diagnosis of the genus Lorryia follows Kaźmierski (1989).Photomicrographs were taken with an AxioCam ICc5 digital camera.For SEM microscopy several alcoholpreserved mites were dried in a JFD 320 freeze drying device (JEOL, Japan), dusted with gold and scanned with a JEOL-JSM-6510LV and TESCAN Mira3 LMU SEM microscopes.All measurements are given in micrometers (μm) for the holotype and for five paratypes (in parentheses).
Male -Similar to female and differs only in having longitudinal slit-like genital opening and four pairs of short and barbed eugenital setae (Figs 4,8D).Two pairs of round genital papillae clearly visible inside progenital chamber (Fig. 8D).

Type deposition
The holotype, one female and one male paratype are deposited in the acarological collection of Zoological Institute of RAS, Saint Petersburg, Russia; other paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.

Etymology
The name of the new species refers to its geographical distribution in Siberia.

Differential diagnosis
The new species closely resembles L. catenulata (Thor, 1931) and L. polita Kuznetsov, 1975a in having ornamentation type "Lorryia" with discrete areas separated by striate cuticle and in having a very short palptarsus.The new species differs from both L. catenulata and L. polita in having irregular reticulate meshes (vs.regular, similar in shape in L. catenulata and L. polita), cross-ties "Y" or "X"-shaped, with their ends and "I"-shaped costulae directed along frames of meshes (vs.cross-ties "Y"-shaped, their ends and "I"-shaped costulae directed transversely from frames of meshes in L. catenulata and L. polita), and in having more blunted dorsal idiosomal setae (pointed in L. catenulata and L. polita).
Female -Similar to male and differs only in having different shape of genital aperture (Fig. 13D) and lacking eugenital setae.Two pairs of round genital papillae clearly visible inside progenital chamber (Fig. 13E).

Type deposition
The holotype, four female and one male paratypes are deposited in the acarological collection of Zoological Institute of RAS, Saint Petersburg, Russia; other paratypes are deposited in the collection of the Tyumen State University Museum of Zoology, Tyumen, Russia.

Etymology
The name of the new species is derived from Latin speciosus meaning beautiful and refers to the very impressive ornamentation of dorsal idiosoma.
Male similar to female and differs only in having longitudinal slit-like genital opening (Fig. 19C) and four pairs of short and barbed eugenital setae.

Remarks
Lorryia evansi was described from quarantine in USA (New York) on cut flowers imported from the Netherlands (Baker 1968a).This species is very similar to L. polygonata Kulczyck1, 1992 described from Ukraine.According to keys provided by Kaźmierski (1998) and Silva et al. (2016), L. evansi differs from L. polygonata only by smooth or rough dorsal idiosomal setae, while in L. polygonata dorsal idiosomal setae clearly serrated.I examined several specimens of L. polygonata collected by me on apple bark in Ukraine.In fact, the dorsal setae in L. polygonata are smooth or rough, not clearly serrated.In the original description of L. polygonata the author also mentioned that most of the setae are smooth or just have few very small barbs apically.However, L. polygonata can be distinguished from L. evansi by distinctly thicker setae f2, h1, h2, and ps1; setae f2 clearly thicker and more blunt than f2 (Fig. 19D); in contrast to subequal in width and shape of setae f1 and f2 in L. evansi (Fig. 19A).
Lorryia catenulata (Thor, 1931) Retetydeus catenulatus Thor, 1931 This species originally was described from Norway (Thor 1931).Baker (1968a) redescribed it based on specimens from Ireland.Kaźmierski (1980) redescribed it based on materials from Poland.Kuznetsov and Petrov (1984) recorded this species in Latvia.According to Kuznetsov and Petrov (1984) this species also was recorded in European Russia (Voronezh Region), Georgia and Ukraine.Momen and Lundqvist (1995) reported it from Sweden.Kaźmierski et al. (2018) noted that this species prefers such habitats as moss covering shady rocks in dark needle forests.Kuznetsov and Petrov (1984) provided an illustration of L. catenulata which, in fact, repeat the illustration of L. polita Kuznetsov, 1975a, a closely related species described from Georgia.Most likely, they consider L. polita as a suspected junior synonym of L. catenulata.According to the key of Kaźmierski (1998) L. polita can be distinguished from L. catenulata in having separate reticulated area A[c2]0[e1] between setae c2 and e.In fact, in the original description of Thor (1931) this area is clearly depicted as well as in redescription of Baker (1968a).My specimens from Western Siberia fully correspond to the description of Thor (1931), especially  22A).For the separation or possible synonymy of L. polita, I examined the holotype of this species (Figs.21C, D, 22C, D).Both species are very similar, however, the reticulate area A[c2]0[e1] in L. polita is hardly discernible on the left side and is clearly separated from area Ac2 on the right side of the holotype (Fig. 22D).Therefore, the use of this character for the separation of L. polita and L. catenulata is problematic.The study of palpal setae revealed some minor differences between L. polita and L. catenulata.In L. catenulata seta ba of the palptarsus is very short and blunt-tipped, distinctly shorter than seta acm and seta v is pointed (Fig. 21A, B); in L. polita seta ba is unusually long and thin, pointed, subequal in length with acm, and seta v is clearly blunt-tipped (Fig 21C , D).There are no differences in the shape of dorsal idiosomal setae and structure of reticulate areas on the idiosoma.In L. catenulata, the dorsal idiosomal setae are weakly barbed and pointed (Fig. 20C, D), and in L. polita the dorsal idiosomal setae not so strongly barbed as in the original description.Another character, which could be used for the separation of L. polita from L. catenulata, is the shape of striae between ventral setae 3a and 4a.In L. catenulata striae form a "V"-shaped ornament (Fig. 22B), while in L. polita striae are parallel (Fig. 22C).
This species was described from Sweden (Momen and Lundqvist 1996).It was also recorded and redescribed from Poland (Kaźmierski 2009).This is the first record of L. fusiformis in Russia.
Brachytydeus szeptyckii Kaźmierski, 2009, 80 This species was described from Poland (Kaźmierski 2009).It was originally placed in the genus Brachytydeus, but according to modern taxonomy of Tydeidae it should be placed in the genus Lorryia sensu Kaźmierski (1989).This is the first record of L. szeptyckii from Russia.
Tydeus serpettae Momen and Lundqvist, 2005, 233 Brachytydeus serpettae: Silva et al. 2016, 25 This species was described from Sweden (Momen and Lundqvist 2005).It was originally placed in the genus Tydeus, but according to modern taxonomy of Tydeidae it should be placed in the genus Lorryia sensu Kaźmierski (1989).This is the first record of L. serpettae from Russia.

Remarks
Paralorryia formosa (André) is very similar morphologically to Paralorryia formosa Livshitz, 1972.In the original description of P. formosa Livshitz the leg chaetotaxy is not described and its taxonomic position is not clear.I examined the holotype of P. formosa Livshitz and found that, besides striation type "Paralorryia", it differs from P. formosa (André) in having two setae on femur III and according to the modern system of Tydeidae P. formosa Livshitz should be placed in the genus Nudilorryia Kaźmierski, 1996, i. e. Nudilorryia formosa (Livshitz, 1972) n. comb.

Discussion
The present research revealed a diverse fauna of Tydeidae in Western Siberia.However, there are many still undescribed and unidentified species in my collection, which will be described and reported later.Most of these new species were collected in the Altai Mountains.During this study, I found well-developed genital papillae in adults of several species of Tydeidae, including Lorryia sibiriensis n. sp., L. speciosa n. sp., L. polita and L. catenulata.According to André (1981a) genital papillae (acetabula) in adults of Tydeidae are present, but hardly discernible.Moreover, I have never seen illustrations of the genital papillae in adults of Tydeidae in any publication.The presence of well-developed genital papillae potentially could be used in taxonomy of Tydeidae, probably in separation of species groups, etc.However, more detailed research of previously described species is necessary.

Figure 13
Figure13DIC micrographs of Lorryia speciosa n. sp., female (A-E) and male (F): A -dorsal setae and ornamentation type "mountains″; B -metapodosomal venter; C -gnathosoma in ventral view, arrow points to short basal part of cheliceral stylet; D -ano-genital area of female; E -progenital chamber of female with well-developed genital papillae (arrowed); F -progenital chamber of male with well-developed genital papillae (arrowed).