Introduction

Root vole Microtus oeconomus (Pallas, 1776) is one of the most widespread members of the Cricetidae family. It is a boreal species; its continuous area in Europe does not extend south of the 50° latitude. It is found in the northern and central parts of Europe, from the Scandinavian Peninsula to the Pyrenees, Alps and Carpathian Mountains in the south, throughout Eastern Europe, West Siberian Plain, Central Siberian Plateau and the northern part of Mongolia and China. In the Nearctic Region, it occurs in the north-western part of North America, including Alaska and north-west Canada (Pucek 1981; Brunhoff et al. 2003). There are six subspecies of root vole in Europe (Lance and Cook 1998) and 30 subspecies worldwide (Shenbrot and Krasnov 2005). Apart from the adjacent area of occurrence, in The Netherlands, Norway, Finland and southern parts of Central Europe (Austria, Hungary, Slovakia) below 50° latitude, there are isolated populations of root voles, considered relict from the last glaciation period (Racz et al. 2005; Thissen et al. 2015; Hulejová Sládkovičová et al. 2018).

Microtus oeconomus plays an important role in maintaining zoonotic outbreaks in the environment, as a reservoir of many pathogens transmitted by arthropods – tick-borne encephalitis (TBE) virus, Babesia microti and others (Karbowiak et al. 2005, 2016; Grzeszczuk et al. 2006; Tołkacz et al. 2018; Grzybek et al. 2020). The wide geographic range of the root vole affects the large number and variety of associated ectoparasite arthropods.

This paper is an analytical review summarizing the available data on parasitic arthropods associated with M. oeconomus across their range of distribution. Papers were collected from websites including PubMed, Google Scholar, Web of Science, Scopus, ScienceDirect. Preliminary phrases or keywords, including root-vole and Microtus oeconomus names, and names of taxa of different levels of external parasites, were used to search for papers about infestation of the rodent species with ticks, mites, fleas and sucking lice. For the second step, new basic keywords were included in an additional search for supplementary papers, about infestation spectrum of biological stages of ticks and mesostigmated mites infesting root vole, the spectrum of other hosts of ticks, mites, fleas and sucking lice, the geografic distribution. The third stage was the analysis of the reference list in publications collected during the first and second stages. The aim was to find records not included in the world databases, that is, published before the spread of the Internet. For the evaluation of the quality of papers, the selected records required commonly used standards such as layout, properly described study methods, reliable results, correct conclusions, correct naming and terminology.

The review covers obligatory and facultative parasitic species. Commensals and arthropods otherwise associated with the rodent, although they are, for example, an important element of the nest fauna or interact in various ways with parasites, have been omitted. The attention was paid to the general abundance of parasitic species, their diversity, and differences in the composition of parasitofauna in particular zoogeographic regions.

The list includes 114 species of arthropods, associated with the root vole, which have been mentioned as parasites in the literature until the completion of the article (in 2022). The most important information is given - synonyms present in parasitological literature, geographical occurrence, range of hosts, place and authors of records of associations with M. oeconomus and, if possible, infestation prevalence or similar data. The classification and names of arthropod species are given after Wegner (1966), Skuratowicz (1967), Krasnov (2008), Krantz and Walter (2009), and Guglielmone et al. (2014). Species names are used according to the review papers by majority of European authors, though some of these might be treated as synonyms.

The short description of each species follows the same pattern: valid taxonomic name; the commonly used synonyms; distribution (and, if necessary, additional data affecting the spread); host range, with an indication of the most important host, if any; records on M. oeconomus; prevalence and intensity of infestation of M. oeconomus, if possible.

Mites (Acari)

Ixodida, Ixodidae

Dermacentor reticulatus (Fabricius, 1794)

Syn. Dermacentor pictus (Hermann, 1804)

Distribution: Europe, West Siberian Plain, excluding most northern and southern parts (Filippova 1997; Karbowiak and Kiewra 2010; Nowak-Chmura 2013; Guglielmone et al. 2014). Host range: preferred hosts of immature stages are small microtid rodents, also other small mammals (Karbowiak 2000), adults feed on large mammals (Nowak-Chmura 2013). Records: Poland (Szymański 1987; Karbowiak et al. 2019, 2022), Slovakia (Nosek and Sixl 1972); Belarus (Savitsky and Kulnazarov 1988; Kononova 1996), Altai Mts. (Bogdanov and Yakimenko 2016). Prevalence: 75.2% (Kononova 1996), 6.5 to 100.0%, average 13.9% depending on the season (Karbowiak et al. 2022).

Haemaphysalis concinna Koch, 1844

Distribution: Western and Eastern Europe, Russia, Japan, China, excluding northern areas (Filippova 1997; Siuda 1993; Estrada-Peña et al. 2017). Host range: many species of mammals and birds. Records: Slovakia (Nosek and Sixl 1972), Altai Mts. (Bogdanov and Yakimenko 2016). Prevalence: considered as rare parasite (Bogdanov and Yakimenko 2016).

Ixodes (Ixodiopsis) angustus Neumann, 1899

Distribution: Russian Far East, excluding northern areas, Japan, Alaska, Pacific Northwest; montane-boreal species (Filippova 1977; Guglielmone et al. 2014). Ixodes angustus occurs in cool, moist mountain habitats. Host range: rodents, nest parasite. Records: Alaska (Fay and Rausch 1969; Timm 1985), former USSR countries without exact location (Filippova 1977).

Ixodes apronophorus Schulze, 1924

Distribution: Great Britain, northern parts of Central and Eastern Europe, Western Siberian Plain (Filippova 1977; Siuda 1993; Nowak-Chmura 2013; Guglielmone et al. 2014; Estrada-Peña et al. 2017). Host range: rodents and insectivores; all developmental stages. Records: Poland (Karbowiak et al. 2022), Slovakia (Kiefer et al. 1982), countries of former SU (Bregetova et al. 1955; Filippova 1977), Western Siberia (Korallo-Vinarskaya et al. 2021), Altai Mts. (Bogdanov and Yakimenko 2016). Prevalence: 0.5% (Karbowiak et al. 2022).

Ixodes pavlovskyi Pomerantsev, 1946

Distribution: Altai Mountains, Central Siberian Plateau (Filippova 1977). Hosts: almost every species of terrestrial mammals. Adult ticks attack large and medium-sized mammals, nymphs and larvae small and medium-sized animals (Filippova 1977). Records on M. oeconomus - according to Filippova (1977) widespread on this rodent in Russia from Altai Mts. to Eastern Siberia; however, the frequency of occurrence and exact locations are not given.

Ixodes persulcatus Schultze, 1930

Distribution: North-Eastern Europe, Western Siberian Plain, Central Siberian Plateau, Russian Far East, Japan (Filippova 1977; Guglielmone et al. 2014). Host range: every species of land mammals; adults attack large and medium-sized mammals, nymphs and larvae small and medium-sized animals (Filippova 1977; Siuda 1993; Nowak-Chmura 2013; Guglielmone et al. 2014). Records: Western Siberia (Krasnov et al. 2010), Altai Mts. (Bogdanov and Yakimenko 2016), Transbaikal (Mel’nikova et al. 2015).

Ixodes ricinus Linnaeus, 1758

Distribution: Europe and western Asia, without northern areas, Western Siberian Plain, isolated populations in West-Northern Africa, Turkey (Filippova 1977; Siuda 1993; Nowak-Chmura 2013; Guglielmone et al. 2014; Estrada-Peña et al. 2017). Host range: adults on large and medium-sized mammals, nymphs and larvae on small and medium-sized mammals and birds (Siuda 1993; Nowak-Chmura 2013; Guglielmone et al. 2014). Records: Poland (Bitkowska and Żukowski 1975; Haitlinger 2010, 2015; Karbowiak et al. 2019, 2022), Belarus (Savitsky and Kulnazarov 1988; Kononova 1996). Prevalence: 9.1 − 11.0% (Kononova 1996; Karbowiak et al. 2022).

Ixodes (Exopalpiger) trianguliceps Birula, 1895

Distribution: Great Britain, Central and Eastern Europe, Western Siberian Plain, Central Siberian Plateau (Filippova 1977; Guglielmone et al. 2014; Estrada-Peña et al. 2017). Host range: each developmental stage feeds on small mammals. Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), Belarus (Savitsky and Kulnazarov 1988; Kononova 1996), Ural (Korenberg and Lebedeva 1969). Prevalence: 15.7% (Kononova 1996).

Mesostigmata, Parasitidae

Parasitus (Eugamasus) kraepelini Berlese, 1903

Syn. Eugamasus kraepelini Bregetova 1956; Vulgarogamasus kraepelini (Berlese, 1905)

Distribution: Europe, West Siberian Plain, Central Siberian Plateau, Russian Far East (Leitner 1946; Edler and Mehl 1972; Klimov 1998). Host range: small mammals, facultative nesting parasite (Edler and Mehl 1972; (Stanko 1990a, b). Records: Poland (Haitlinger 1983, 1989, 2015; Karbowiak et al. 2022), Belarus (Savitsky and Kulnazarov 1988). Prevalence: 1.0% (Savitsky and Kulnazarov 1988).

Parasitus (Eugamasus) oudemansi (Berlese, 1903)

Syn. Vulgarogamasus oudemansi (Berlese, 1904)

Distribution: Western Europe, Russia, Northern Kazakhstan, West Siberian Plain, South Siberian and Altai Mts., China (Bregetova 1956; Luo et al. 2007). Host range: mole Talpa europaea Linnaeus, 1758; nest parasite (Bregetova 1956). Records: Poland ((Haitlinger 1987a), Belarus (Savitsky and Kulnazarow 1988), Kuril Islands (Klimov 1998). Prevalence: 7.9% (Savitsky and Kulnazarov 1988).

Mesostigmata, Ologamasidae

Cyrtolaelaps chiropterae Karg, 1971

Distribution: Europe (Gwiazdowicz and Sznajdrowski 1999). Host range: many rodent species, facultative nest parasite (Gwiazdowicz and Sznajdrowski 1999). Record: Belarus. Prevalence: 2.6% (Savitsky and Kulnazarov 1988).

Cyrtolaelaps mucronatus G. et R. Canestrini, 1881

Distribution: Europe, West Siberian Plain, Central Siberian Plateau, Russian Far East (Leitner 1946; Bregetova 1956). Host range: Apodemus mice, also other rodents and insectivores; facultative nest parasite mainly as deutonymph (Haitlinger 1984a, 1987b; (Stanko 1990a, b; Ambros et al. 1985). Records: Belarus. Prevalence: 1.0% (Savitsky and Kulnazarov 1988).

Mesostigmata, Laelapidae

Androlaelaps fahrenholzi (Berlese, 1911)

Syn. Androlaelaps glasgowi Ewing, 1925; Haemolaelaps glasgowi Ewing, 1925

Distribution: cosmopolitan (Hansen 1964; Whitaker and Wilson 1974; Vinarski and Korallo-Vinarskaya 2016). Host range: Microtinae and Murinae, facultative nest parasite (Bregetova 1956; Airoldi et al. 1989; (Stanko 1990a, b). Records: Poland (Haitlinger 2015), Belarus (Savitsky and Kulnazarov 1988; Kononova 1996), Volga River basin (Kirillova and Kirillov 2018), western Siberia (Tagiltzev 1967; Krasnov et al. 2010), Altai Mts. (Bogdanov and Yakimenko 2016), Northern America (Whitaker and Wilson 1974; Timm 1985). Prevalence: 3.1–6.8% (Tagiltzev 1967; Savitsky and Kulnazarov 1988), often dominant (Bregetova 1956; Airoldi et al. 1989; (Stanko 1990a, b).

Androlaelaps semidesertus (Bregetova, 1952)

Distribution: southern Asiatic Russia (Bregetova 1956; Vinarski and Korallo-Vinarskaya 2016). Host range: small rodents, insectivores, hares and goophers (Bregetova 1956). Record and prevalence: Kazakhstan, single specimens (Sineľshchikov 1967).

Haemogamasus ambulans (Thorell, 1872)

Syn. Euhaemogamasus ambulans Allred, 1957

Distribution: cosmopolitan (Bregetova 1956; Hansen 1964; Edler and Mehl 1972; Whitaker and Wilson 1974; Borisova and Nazarova 1986; Schmölzer 1991; Whitaker et al. 2007; Vinarski and Korallo-Vinarskaya 2017). Host range: Microtus agrestis (Linnaeus, 1761), rarely other voles, insectivores, birds; nest parasite (Korneev 2003). Records: Scandinavia (Edler and Mehl 1972; Lundquist and Brinck-Lindroth 1990), Poland (Bitkowska and Żukowski 1975; Haitlinger 1988, 2015; Karbowiak et al. 2022), Slovakia (Mrciak and Rosický 1956; Ambros and Dudich 1996; Mašán and Fenďa 2010), northern and western Siberia (Krasnov et al. 2010), Altai Mts. (Bogdanov and Yakimenko 2016), Alaska (Williams et al. 1978), Northern America without exact locality (Timm 1985; Whitaker et al. 2007). Prevalence: 0.7–22.2 to 32.0% (Lundquist and Brinck-Lindroth 1990; Karbowiak et al. 2022).

Haemogamasus ghanii Williams, 1978

Distribution: Alaska. Host range: voles Microtus miurus Osgood, 1901, M. oeconomus and Myodes rutilus (Pallas, 1779) (Whitaker et al. 2007). Records: Alaska (Williams et al. 1978).

Haemogamasus hirsutosimilis Willmann, 1952

Distribution: Europe, steppe zone of West Siberian Plain (Bregetova 1956; Mašán and Fenďa 2010; Vinarski and Korallo-Vinarskaya 2017). Host range: Apodemus mice, occasionally voles; facultative nest parasite (Mašán and Fenďa 2010). Records: Poland (Kozłowski and Żukowski 1958a, b; (Haitlinger 1988, 2008; Karbowiak et al. 2022). Prevalence: 0.7–5.3% (Karbowiak et al. 2022).

Haemogamasus hirsutus Berlese, 1889

Distribution: Western and Southern Europe, middle part of Russia and West Siberian Plain. Host range: genera Arvicola, Rattus, Mus, Microtus, T. europaea; facultative nest parasite, hematophagous (Bregetova 1949; Airoldi et al. 1989). Records: Poland (Kiełczewski 1958; Haitlinger 1988, 2008, 2010), Belarus (Savitsky and Kulnazarov 1988; Kononova 1996). Prevalence: 1.0% (Savitsky and Kulnazarov 1988). Found as single specimens usually, the nymphs more often than adults, moreover the nymphs prefer fur and the adults the nests (Edler and Mehl 1972; (Stanko 1990a, b).

Haemogamasus horridus Michael, 1892

Distribution: Europe, the Near East, Kyrgyzstan, and South America, absent in Northern America (Vinarski and Korallo-Vinarskaya 2017; Whitaker et al. 2007). Host range: rodents and insectivores; facultative haematofagous, nest parasite (Bregetova 1949; Stanko 1990a, b). Records: Belarus (Savitsky and Kulnazarov 1988), Russia (Bregetova 1956). Prevalence: 1.0% (Savitsky and Kulnazarov 1988), it is present as adults and nymphs on low number usually (Mašán and Fenďa 2010).

Haemogamasus liponyssoides Ewing, 1925

Distribution: Europe, West Siberian Plain, Central Siberian Plateau, Russian Far East, southern Canada, eastern United States, including the extreme north latitudes (Hansen 1964; Whitaker and Wilson 1974; Timm 1985; Haitlinger 1988; Klimov 1998; Vinarski and Korallo-Vinarskaya 2017). Host range: T. europaea, also rodents and insectivores (Haitlinger 1988; Korneev 2003). Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), Kuril Islands (Klimov 1998). Prevalence: 0,6% (Lundquist and Brinck-Lindroth 1990).

Haemogamasus mandschuricus Vitzthum, 1930

Distribution: West Siberian Plain, Central Siberian Plateau, China, Japan, Northern America to California, Oregon and Utah; boreal species (Bregetova 1955; Bregetova 1956; Hansen 1964; Whitaker and Wilson 1974). Host range: rodents of Arvicolinae subfamily, also shrews, in small number of specimens usually; nidicolous parasite (Bregetova 1955). Record: Western Siberia (Krasnov et al. 2010).

Haemogamasus nidi Michael, 1892

Distribution: Europe, Middle and Eastern Asia, Japan, Northern America, Greenland (Bregetova 1956; Vinarski and Korallo-Vinarskaya 2017). Host range: rodents and insectivores, small birds, bats; facultative host-nest parasite (Bregetova 1949; Bregetova and Vysotskaia 1949; Zeman and Jurík 1981; Haitlinger 1987b, 1988, 2015). Records: Scandinavia (Edler and Mehl 1972; Lundquist and Brinck-Lindroth 1990), Slovakia (Ambros and Dudich 1996; Mašán and Fenďa 2010), Poland (Haitlinger 2009; Karbowiak et al. 2022), Belarus (Savitsky and Kulnazarov 1988; Kononova 1996), Volga River basin (Borisova and Nazarova 1986; Kirillova and Kirillov 2018), Western Siberia (Krasnov et al. 2010). Prevalence: 0.7–44.4% (Karbowiak et al. 2022); often dominant (Lundquist and Brinck-Lindroth 1990; Stanko 1990a, b; Savitsky and Kulnazarov 1988; Kononova 1996).

Haemogamasus nidiformes Bregetova, 1955

Distribution: northern and central parts of Eurasia, except extreme north-east of Asia (Edler and Mehl 1972; Mašán and Fenďa 2010; Vinarski and Korallo-Vinarskaya 2017). Host range: Murinae, less often Microtinae rodents and insectivores; host-nest parasite. Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), Western Siberia (Krasnov et al. 2010), Altai Mts. (Bogdanov and Yakimenko 2016). Prevalence: 4.9% (Lundquist and Brinck-Lindroth 1990).

Haemogamasus reidi Ewing, 1925 (Keegan, 1951)

Distribution: Canada, over most of the United States (Williams et al. 1978; Timm 1985). Host range: genera Neotoma, Microtus. Records: as parasite of M. oeconomus noted by Whitaker and Wilson (1974).

Hirstionyssus ellobii Bregetova, 1956

Distribution: Southern and Eastern Europe, Central Asia (Kirillova and Kirillov 2018). Host range: Microtinae and Murinae rodents. Record: Volga River basin (Kirillova and Kirillov 2018).

Hirstionyssus gudauricus Razumova, 1957

Distribution: Northern and Central Europe, West Siberian Plain, Central Siberian Plateau; boreo-montane (Edler and Mehl 1972; Vinarski and Vinarskaya 2020). Host range: Chionomys (Microtus) nivalis (Martins, 1842), also other voles. Records: Scandinavia (Edler and Mehl 1972), Yakutia (Nikulina and Pavlova 2007). Prevalence and intensity: relatively low usually (Mašán and Fenďa 2010).

Hirstionyssus isabellinus (Oudemans, 1913) s. Evans et Till, 1966

Syn. Echinonyssus isabellinus (Oudemans, 1913)

Distribution: Northern and Central Europe, West Siberian Plain, Central Siberian Plateau, Northern America, including extreme North (Bregetova et al. 1955; Hansen 1964; Mitchell and Behin 1965; Whitaker and Wilson 1974; Airoldi et al. 1989; Stanko 1990a, b>; Luo et al.2007; Çicek et al. 2008; Mašán and Fenďa 2010, Vinarski and Vinarskaya 2020). Host range: voles and many rodent and insectivore species; nest-host parasite (Bregetova 1956; Ambros et al. 1985). Records: Scandinavia (Edler and Mehl 1972; Lundquist and Brinck-Lindroth 1990), Poland (Bitkowska and Żukowski 1975; Haitlinger 2010, 2015), Belarus (Savitsky and Kulnazarov 1988; Kononova 1996), Kazakhstan (Sineľshchikov 1967; Tagiltzev 1967); Volga River basin (Borisova and Nazarova 1986), Western Siberia (Krasnov et al. 2010), Altai Mts. (Bogdanov and Yakimenko 2016), on American subspecies of M. oeconomus mentioned by Whitaker and Wilson (1974). Prevalence: 1.6–76.4% (Tagiltzev 1967; Savitsky and Kulnazarov 1988); on animals occur adult forms usually (Ambros et al. 1985).

Hirstionyssus soricis Turk, 1945

Syn. Echinonyssus soricis Tenorio, 1984; Hirstionyssus eusoricis Bregetova, 1956

Distribution: woodland zone of Europe, Kazakhstan, West Siberian Plain (Edler and Mehl 1972; Korallo 2009; Vinarski and Korallo-Vinarskaya 2020). Host range: shrews, rarely rodents, birds; nest parasite (Mašán and Fenďa 2010). Records: Novosibirsk region, Western Siberia (Nikulina and Pavlova 2007; Korallo 2009; Krasnov et al. 2010).

Hirstionyssus sunci Wang, 1962

Syn. Hirstionyssus musculi (Johnston, 1849), Hirstionyssus latiscutatus de Meillon & Lavoipierre, 1944; Hirstionyssus apodemi Zuevsky, 1970

Distribution: Europe, Western Asia, New Zealand (Tenquist and Charleston 2001; Mašán and Fenďa 2010). Host range: mainly Murinae, to a lesser extent Microtinae. Records: Belarus (Savitsky and Kulnazarov 1988), Kazakhstan, the delta of the Irtysh River (Sineľshchikov 1967). Prevalence: 0.2 − 1.6% (Tagiltzev 1967; Savitsky and Kulnazarov 1988).

Hirstionyssus talpae (Zemskaya, 1954)

Distribution: Eurasia and North America (Whitaker and Wilson 1974), reported also from New Zealand (Tenquist and Charleston 2001). Host range: T. europea (Mašán and Fenďa 2010), also other insectivores and rodents. Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), European part of Russia (Nikulina and Pavlova 2007).

Hirstionyssus transiliensis Bregetova, 1956

Distribution: steppe zone of Northern and Central Asia, the Near East (Vinarski and Vinarskaya 2020). Host range: Microtinae rodents, preferred Microtus arvalis and Microtus gregalis (Pallas, 1779); nest parasite. Records: western Siberia, Omsk, Tuve and Novosibirsk District (Russia) (Nikulina and Pavlova 2007; Korallo 2009).

Eulaelaps cricetuli Vitzthum, 1930

Distribution: Northern and Central Asia, Far East excluding the northernmost latitudes (Vinarski and Korallo-Vinarskaya 2017). Host range: Cricetulus barabensis (Pallas, 1773),

Phodopus roborovskii (Satunin, 1903); facultative hematophage (Bregetova 1956; Nikulina and Pavlova 2007). Record: Transbaikal (Nikulina and Pavlova 2007).

Eulaelaps stabularis (C.L. Koch, 1836)

Distribution: cosmopolitan, the northern border of its distribution coincides with the boundary of the forest-tundra zone (Vinarski and Korallo-Vinarskaya 2017). Host range: small mammals and birds; facultative nesting parasite (Bregetova and Vysotskaya 1949; Zeman and Jurík 1981; Haitlinger 1987b; Airoldi et al. 1989). Records: Scandinavia (Edler and Mehl 1972), Poland (Kiełczewski 1958; Bitkowska and Żukowski 1975; Haitlinger 1988, 2009, 2015), Slovakia (Ambros and Dudich 1996; Mašán and Fenďa 2010), Belarus (Savitsky and Kulnazarov 1988; Kononova 1996), Kazakhstan (Sineľshchikov 1967), western Siberia (Nikulina and Pavlova 2007; Krasnov et al. 2010), Altai Mts. (Bogdanov and Yakimenko 2016), mentioned in isolated population in Hungary (Ambros 1987) and in American subspecies M. oeconomus (Whitaker and Wilson 1974).

Hyperlaelaps amphibius Zachvatkin, 1948 s. Evans et Till, 1966

Syn. Hyperlaelaps amphibia Evans et Till, 1966

Distribution: Northern Eurasia, excluding Russian Far East (Vinarski and Korallo-Vinarskaya 2016). Host range: Arvicola terrestris (Linnaeus, 1758), associated with the presence of that rodent (Bregetova 1956; Nikulina and Pavlova 2007; Mašán and Fenďa 2010), also Microtus (Mašán and Fenďa 2010). Records: Volga River basin (Borisova and Nazarova 1986; Korneev 2003).

Hyperlaelaps arvalis (Zachvatkin, 1948)

Syn. Hyperlaelaps microti (Ewing, 1933)

Distribution: Northern Europe, North-Western Asia, China, USA (Edler and Mehl 1972; Luo et al. 2007; Vinarski and Korallo-Vinarskaya 2016). Host range: M. arvalis, rarely other rodents and insectivores (Bregetova and Vysotskaya 1949; Bregetova 1956; Haitlinger 1984b, 1989, 2015; Stanko 1990a, b; Mašán and Fenďa 2010). Records: Scandinavia (Edler and Mehl 1972; Lundquist and Brinck-Lindroth 1990), Poland (Bitkowska and Żukowski 1975; Kiełczewski 1958; Haitlinger 2010), Slovakia (Ambros and Dudich 1996; Mašán and Fenďa 2010; Poláčiková 2013), Lituania (Kaminskienė et al. 2020), Hungary (Ambros 1987), Belarus (Savitsky and Kulnazarov 1988; Kononova 1996), Kazakhstan (Sineľshchikov 1967), Volga River basin (Borisova and Nazarova 1986; Kirillova and Kirillov 2018), Siberia (Tagiltzev 1967; Nikulina and Pavlova 2007; Mal’kova 2010) Altai Mts. (Bogdanov and Yakimenko 2016). Prevalence: 10.0-17.9% (Tagiltzev 1967; Savitsky and Kulnazarov 1988), often dominant (Edler and Mehl 1972; Poláčiková 2013).

Hypoaspis murinus Strandtmann et Menzies, 1948

Distribution: Europe, Kazakhstan, Armenia, USA (Bregetova 1956). Host range: Rattus, Apodemus (Strandtmann and Menzies 1948). Record and prevalence: Russia, 0.1% (Tagiltzev 1967).

Laelaps agilis C.L.Koch, 1836 s. Korg, 1971

Distribution: Europe, Northern and Central Asia (Vinarski and Korallo-Vinarskaya 2016). Host range: Apodemus flavicollis (Melchior, 1834), less other small mammals; host-dwelling parasite (Ambros et al. 1985; Stanko 1990a, b). Records: Poland (Kiełczewski 1958), Slovakia (Ambros and Dudich 1996; Mašán and Fenďa 2010), Lithuania (Kaminskienė et al. 2020), Belarus (Savitsky and Kulnazarov 1988), Kazakhstan (Sineľshchikov 1967). Prevalence: 15.2%, dominant (Savitsky and Kulnazarov 1988).

Laelaps algericus Hirst, 1925

Distribution: Northern and Central Africa, Europe, West Siberian Plain, Transbaikal (except the northern latitudes), Southern China (Luo et al. 2007; Çicek et al. 2008; Vinarski and Korallo-Vinarskaya 2016). The northern border of occurrence area reaches Carpathian Mountain range (Bregetova 1956). Host range: Mus; nest parasite (Mašán and Fenďa 2010; Várfalvyová et al. 2011). Records: Belarus (Savitsky and Kulnazarov 1988), the delta of the Irtysh River (Tagiltzev 1967). Prevalence: 0.2–1.0% (Tagiltzev 1967; Savitskiy and Kulnazarov 1988).

Laelaps clethrionomydis Lange, 1955

Distribution: Europe, West Siberian Plain, Central Siberian Plateau, Russian Far East, Korean Peninsula, Japan, Alaska, Canada; boreo-montane (Bregetova 1956; Yamashita and Konno 1958; Mitchell and Behin 1965; Whitaker and Wilson 1974; Timm 1985; Luo et al. 2007; Balashov et al. 2007; Vinarski and Korallo-Vinarskaya 2016). Host range: Myodes (Ambros 1990; Mašán and Fenďa 2010), M. gregalis, also other rodents (Edler and Mehl 1972). Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), Belarus (Kononova 1996), Kazakhstan (Sineľshchikov 1967), Western Siberia (Krasnov et al. 2010).

Laelaps hilaris C.L. Koch, 1836

Distribution: Europe, West Siberian Plain, Central Siberian Plateau, Russian Far East except northern parts (Bregetova 1956; Edler and Mehl 1972; Çicek et al. 2008; Vinarski and Korallo-Vinarskaya 2016). Host range: M. arvalis and other Microtus, occasionally Apodemus (Zakhvatkin 1948; Bregetova and Vysotskaja 1949; Zeman and Jurík 1981; Ambros 1987; Stanko 1990a, b; Mašán and Fenďa 2010). Records: Scandinavia (Edler and Mehl 1972; Lundquist and Brinck-Lindroth 1990), Poland (Haitlinger 1989, 2010, 2015), Slovakia (Ambros and Dudich 1996; Poláčiková 2013), Belarus (Savitsky and Kulnazarov 1988; Kononova 1996), Hungary (Ambros 1987), Kazakhstan (Sineľshchikov 1967), Volga River basin (Borisova and Nazarova 1986), Western Siberia (Krasnov et al. 2010; Maľkova 2010; Kirillova and Kirillov 2018), Altai Mts. (Bogdanov and Yakimenko 2016). Prevalence: 41.0% (Kirillova and Kirillov 2018), often dominant (Mašán and Fenďa 2010).

Laelaps jettmari Vitzthum, 1930

Distribution: Eastern Europe, the southern regions of Northern Eurasia, Transbaikal, China, Japan (Mašán and Fenďa 2010; Vinarski and Korallo-Vinarskaya 2016). Host range: genera Cricetulus (Vinarski and Korallo-Vinarskaya 2016), Apodemus, Mus (Bregetova 1956; Mal’kova 2010). Records: Belarus (Savitsky and Kulnazarov 1988), Western Siberia (Krasnov et al. 2010). Prevalence: 7.3% (Savitsky and Kulnazarov 1988).

Laelaps kochi Oudemans, 1936

Distribution: Alaska, Canada, Utah, Illinoi, Indiana (Whitaker and Wilson 1974). Host range: insectivores, rodents, small carnivores. Records: mentioned by Whitaker and Wilson (1974), Timm (1985).

Laelaps multispinosus Banks, 1909

Distribution: the native range lies in Northern America, presently also West Siberian Plain, Central Siberian Plateau, Russian Far East (Vinarski and Korallo-Vinarskaya 2016). Host range: muskrat Ondatra zibethicus (Linnaeus, 1766), associated with the presence of the host (Bregetova 1956), also M. glareolus (Schreber, 1780), and S. araneus Linnaeus, 1758 (Korneev 2003). Records and prevalence: Volga River basin, Irtysh delta; 0.2% (Tagiltzev 1967; Borisova and Nazarova 1986).

Laelaps muris (Ljungh, 1799)

Distribution: Europe, West Siberian Plain, Central Siberian Plateau, excluding the extreme North (Vinarski and Korallo-Vinarskaya 2016). Host range: A. terrestris, the mite occurs according to their distribution (Bregetova 1956; Ambros et al. 1985; Mašán and Fenďa 2010). Records: Belarus (Savitsky and Kulnazarov 1988), Kazakhstan (Sineľshchikov 1967), the Volga River basin (Borisova and Nazarova 1986; Kirillova and Kirillov 2018), Western Siberia (Krasnov et al. 2010). Prevalence: 1.6% (Savitsky and Kulnazarov 1988).

Myonyssus dubinini Bregetova, 1949

Distribution: West Siberian Plain, Russian Far East (Korneev 2003; Nikulina and Pavlova 2007). Host range: rodents, insectivores, small carnivores. Records: eastern Russia (Korneev 2003; Nikulina and Pavlova 2007).

Myonyssus ingricus Bregetova, 1956

Distribution: Northern, Central and Eastern Europe, Asiatic Russia, except for its extreme northeast; mountains areas (Vinarski and Korallo-Vinarskaya 2016). Host range: Soricidae, in lesser number variety of rodent’s species and their nests. Record and prevalence: western Siberia, rare parasite (Krasnov et al. 2010).

Ololaelaps sellnicki Bregetova et Koroleva, 1964

Distribution: Ukraine, Lithuania, European part of Russia (Beaulieu et al. 2019). Host range: small mammals; facultative parasite. Record: mentioned in Poland by Haitlinger (1987a).

Prostigmata, Trombidiformes, Trombiculidae

Trombicula (Neotrombicula) autumnalis (Shaw, 1790)

Distribution: Europe, Western Russia, Western Asia, USA (Timm 1985; (Haitlinger 1987b). Host range: Murinae, Microtinae, Insectivora; only the larvae are parasitic stages. Records: northern Poland (Kiełczewski 1958; Bitkowska and Żukowski 1975), Belarus (Savitsky and Kulnazarow 1988), the Volga River basin (Borisova and Nazarova 1986). Prevalence: 3.6% (Savitsky and Kulnazarov 1988).

Trombicula (Neotrombicula) zachvatkini (Schluger, 1948)

Syn. Hirsutiella zachvatkini (Schluger, 1948)

Distribution: Northern and Central Europe, eastern Russia to Volga River basin (Balashov et al. 2007, Moniuszko and Mąkol 2014). Host range: microtid voles; larvae are host-nest parasite, adults free living. Records: Poland (Haitlinger 2015), Slovakia (Kováčik and Dudich 1990), Belarus (Savitsky and Kulnazarov 1988). Prevalence: 1.0% (Savitsky and Kulnazarov 1988).

Neotrombicula inopinata (Oudemans, 1909)

Distribution: Central and Southern Europe, Western Russia (Moniuszko and Mąkol 2014). Host range: Murinae, Microtinae, Soricidae, Gliridae (Moniuszko and Mąkol 2014). Records: mentioned by Moniuszko and Mąkol (2014), exact location not specified.

Neotrombicula japonica (Tanaka, Kaiwa, Teramura et Kagaya, 1930)

Distribution: Central and Southern Europe, Russia, China, Japan (Moniuszko and Mąkol 2014). Host range: Murinae, Microtinae, Soricidae (Moniuszko and Mąkol 2014). Records: mentioned by Moniuszko and Mąkol (2014), exact location not specified.

Neotrombicula talmiensis (Schluger, 1955)

Distribution: Europe, Central Asia, Russian Far East (Haitlinger 1981; Stekolnikov et al. 2014). Host range: rodents, Insectivora, lagomorphs, birds and occasionally bats and carnivores (Stekolnikov et al. 2014). Records: Kazakhstan (Stekolnikov 1996), Poland (Hailinger 1981, 2015).

Neotrombicula vulgaris (Schluger, 1955)

Distribution: Central and Southern Europe, Central Asia (Haitlinger 1981, Moniuszko and Mąkol 2014). Host range: Murinae and Microtinae (Moniuszko and Mąkol 2014). Records: Poland (Haitlinger 1981, 2015); Slovakia (Kováčik and Dudich 1990).

Myobiidae

Radfordia (Microtimyobia) lemnina (Koch, 1841)

Distribution: Europe, Russia, China, Japan, Alaska, USA (Dusbábek and Daniel 1975; Uchikawa et al. 1997; Haitlinger 2008, 2010). Host range: Microtus voles (Bochkov 1995; Whitaker and Wilson 1974; Whitaker et al. 2007). Records: Poland, Russia, Armenia (Haitlinger 2015; Bochkov 1995, 2010), isolated population in Netherland (Fain and Lukoschus 1977; Bochkov 1995).

Psorergatidae

Psorergates oeconomi Lukoschus, Fain et Beaujean, 1967.

Distribution: Europe. Host range and record: M. oeconomus arenicola (Giesen 1990 after: Lukoschus et al. 1967).

Psorergates neerlandicus Lukoschus, De Cock, Driessen, 1971.

Distribution: Europe. Host range and record: M. oeconomus (Giesen 1990, after: Lukoschus et al. 1971).

Listrophoridae

Listrophorus brevipes Dubinina, 1968

Distribution: Europe. Host range: microtid rodents, also other rodent genera, Soricidae. Records: Europe, Poland (Bochkov 2010; Haitlinger 2015).

Astigmata, Sarcoptoidea, Myocoptidae

Myocoptes japonensis Radford, 1955

Distribution: Europe, Asia, Kanada, USA (Fain and Hyland 1970, Haitliger 1986). Host range: microtid rodents, also other rodent genera, Soricidae. Records: Poland (Labrzycka 2004; Haitlinger 1986, 2015).

Myocoptes squamosus Fain, Munting et Lukoschus, 1969

Distribution: Netherland, USA (Fain and Hyland 1970; Siepel et al. 2016). Host range: Microtus oeconomus. Records: Netherland, USA (Fain and Hyland 1970; Siepel et al. 2016).

Trichoecius tenax (Michael, 1889)

Distribution: Europe (Bochkov 2010). Host range: microtid rodents, also other rodent genera, Soricidae. Records: Poland (Labrzycka 2004; Haitlinger 1986, 2015).

Siphonaptera

Ceratophyllidae

Amalareus (Malareus) penicilliger (Grube, 1851)

Syn. Ceratophyllus penicilliger Grube, 1852

Distribution: Europe, Central Asia, West Siberian Plain, Central Siberian Plateau, Russian Far East, Northern America; boreo-montane species (Skuratowicz 1967; Lewis 1975; Balashov et al. 2007; Kotti 2018). Host range: microtid rodents, also other rodent genera. Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), Komi Republic (Novozhilova 1967), Transbaikal, Western Siberia (Nikulina 1980; Krasnov et al. 2010), Altai Mts. (Bogdanov and Yakimenko 2016), Alaska (Hopla 1966). Prevalence: 9.8% (Nikulina 1980).

Amalareus (Malareus) telchinus (Rothschild, 1905)

Distribution: eastern Canada and USA (Lewis 1975; Holland 1985). Host range: Peromyscus maniculatus (Wagner, 1845), apart principal, a diversity of rodents and carnivores. Record: mentioned by Holland (1985), without exact location.

Ceratophyllus (Emmareus) garei Rothschild, 1902

Distribution: Europe, Central Asia, China, Japan, Alaska, Canada (Holland 1963; Skuratowicz 1967; Lewis 1975). Host range: small birds, Sciuridae, Apodemus, Microtus; nest parasite (Holland 1963; Litvinov and Litvinova 2003). Records and prevalence: Russia, rare parasite (Nikulina 1980; Krasnov et al. 2010).

Ceratophyllus idius Jordan et Rothschild, 1902

Distribution: Alaska, Canada, Newfoundland, eastern USA, north of about 40˚N latitude (Lewis 1975). Host range: tree swallow Tachycineta bicolor (Vieillot, 1808) and related birds. Records: Alaska (Hopla 1966; Holland 1985). Prevalence - occasionally parasite (Holland 1985).

Ceratophyllus (Monopsyllus) indages Rothschild, 1908

Syn. Ceratophyllus tamias Wagner, 1927

Distribution: Finland, European part of Russia, Central-Asian subregion, East Asian subregion, West Siberian Plain, Central Siberian Plateau, China, Japan; boreal (Lewis 1975; Kotti 2018). Host range: Sciurus, Tamias, Pteromys, sometimes also on small predators (Litvinov and Litvinova 2003; Medvedev et al. 2014). Record and prevalence: Russia, reported as a rare parasite (Krasnov et al. 2010).

Megabothris (Gebiella) advenarius (Wagner, 1927) (= bifallax Ioff, 1950)

Syn. Ceratophyllus advenarius Ioff et Scal., 1950

Distribution: Central Siberian Plateau; Russian Far East, Sakhalin; boreal species (Lewis 1975; Kotti 2018; Vershinin et al. 2019). Host range: microtid rodents. Records: eastern Siberia, Transbaikal, Kamchatka Peninsula (Violovich 1963; Nikulina 1980; Litvinov and Litvinova 2003). Prevalence: 17.7–20.2% (Nikulina 1980).

Megabothris calcarifer (Wagner, 1913)

Syn: Ceratophyllus calcarifer Wagner, 1913

Distribution: Northern Europe, Central Asia, Primorskiy region, Manchuria, Mongolia, Alaska, northwestern Canada (Smit 1967; Nikulina 1980; Holland 1985; Medvedev et al. 2014). Host range: prefers circumpolar population M. oeconomus, also Microtus pennsylvanicus (Ord, 1815), M. rutilus, Lemmus trimucronatus (J. Richardson, 1825). Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), Transbaikal, Russian Far East (Nikulina 1980; Medvedev et al. 2014), Alaska, northwestern Canada (Hopla 1966; Holland 1985). Prevalence: 38.3%, dominant ectoparasite (Nikulina 1980).

Megabothris groenlandicus Wahlgren, 1903

Syn. Ceratophyllus immitis Jordan, 1929

Distribution: Alaska, northern Canada, east Greenland (Holland 1985). Host range: lemmings Dicrostonyx spp., overlap the distribution of hosts. Records: Alaska, Greenland (Holland 1985).

Megabothris quirini (Rothschild, 1905)

Distribution: Alaska, Canada, USA (Holland 1985; Haas et al. 2019). Host range: Soricidae shrews, also M. rutilus and M. oeconomus. Records: Alaska (Hopla 1966; Holland 1985).

Megabothris rectangulatus (Wahlgren, 1903)

Syn. Ceratophyllus rectangulatus Wahlgren, 1903

Distribution: Europe, West Siberian Plain, Central Siberian Platea, Altai Mts., Tian Shan, Yakutia, Transbaikal, Mongolia (Smit 1967; Lewis 1975; Vershinin et al. 2019); boreo-montane species (Skuratowicz 1967). Host range: microtid rodents (Skuratowicz 1967). Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), western Siberia, Komi Republic and Transbaikal, Altai Mts. (Bogdanov and Yakimenko 2016). Prevalence: 19.6% (Novozhilova 1967; Nikulina 1980; Krasnov et al. 2010).

Megabothris taiganus (Scalon, 1950)

Syn. Igioffus taiganus Scalon, 1950; Ceratophyllus taiganus (Scalon, 1950)

Distribution: Central Siberian Plateau, Manchuria, Mongolia (Smit 1966; Kotti 2018). Host range: microtid rodents. Record: Mongolia (Smit 1967).

Megabothris turbidus (Rothschild, 1909)

Syn. Ceratophyllus turbidus Rothschild, 1909

Distribution: British Islands, Finland, Eastern Europe, West Siberian Plain (Skuratowicz 1967; Lewis 1975; Balashov et al. 2007). Host range: genera Apodemus, Myodes, Microtus, also Sciurus vulgaris Linnaeus, 1758, rarely Gliridae (Cyprich et al. 1992, 1999; Stanko et al. 2002), small birds and carnivores (Skuratowicz 1967). Records: Poland (Skuratowicz 1967; Kowalski et al. 2014; Karbowiak et al. 2022; Haitlinger 2010), Slovakia (Cyprich et al. 1984). Prevalence: 2.0-22.2% (Karbowiak et al. 2022).

Megabothris walkeri (Rothschild, 1902)

Syn. Ceratophyllus walkeri Rothschild, 1902

Distribution: Northern Europe, West Siberian Plain, Kazakhstan; occurs on lowland areas usually (Skuratowicz 1967; Lewis 1975). Host range: M. oeconomus, A. terrestris, rarely Neomys shrews. Records: Poland (Haitlinger 2010, 2015; Karbowiak et al. 2022), Belarus (Kononova 1996), western Russia (Korzikov et al. 2018; Krylov 1996); Altai Mts. (Bogdanov and Yakimenko 2016) and on M. o. mehelyi in Danubian Lowland (Cyprich et al. 1984; Dudich 1985; Baláž and Zigová 2020). Prevalence: 27.6–66.7% (Karbowiak et al. 2022); frequent root vole parasite, often dominant (Zwolski 1960; Skuratowicz 1967; Kononova 1996; Kowalski et al. 2014; Karbowiak et al. 2022).

Monopsyllus vison (Baker, 1904)

Distribution: Canada, northern USA (Medvedev et al. 2005). Host range: preferred Blarina brevicauda (Say, 1823), others: Mustela spp., Peromyscus maniculatus (Wagner, 1845) Tamiasciurus hudsonicus (Erxleben, 1777) (Holland 1985). Record: Alaska (Hopla 1966).

Nosopsyllus fasciatus (Bosc d’Antic, 1801)

Distribution: cosmopolitan (Skuratowicz 1967). Host range: Rattus rattus (Linnaeus, 1758), Rattus norvegicus (Berkenhout, 1769), Mus musculus Linnaeus, 1758 (Skuratowicz 1967; Litvinov and Litvinova 2003), rarely Apodemus and Microtus (Stanko et al. 2002). Records: Belarus (Kononova 1996), isolated population of M. o. mehelyi in Danubian Lowland (Baláž and Zigová 2020).

Oropsylla idahoensis (Baker, 1904)

Distribution: Alaska, Canada, western USA (Holland 1985). Host range: concordant with the distribution of the ground squirrel Spermophilus spp., also Citellus, Marmota (Holland 1985). Records: Alaska (Hopla 1966; Haas 1982).

Oropsylla ilovaiskii Wagner et Ioff, 1926

Distribution: Eastern Europe, Kirghizstan, Kazakhstan, steppe zone of Russia (Medvedev et al. 2005; Kirillova and Kirillov 2018). Host range: Cricetinae rodents. Record: north-eastern Kazakhstan (Pakizh 1971).

Leptopsyllidae

Amphipsylla marikovskii Ioff et Tiflov, 1939

Distribution: the trans-Beringian range. There are two subspecies: A. marikovskii marikovskii Ioff et Tiflov, occurs in the eastern Siberia (Holland 1963), the principal hosts are M. gregalis and Chionomys voles, on other rodents it parasitizes in lower densities (Litvinov and Litvinova 2003; Shenbrot et al. 2007), A. marikovskii ewingi, Nearctic representative, associated to M. o. macfarlani, M. o. operarius, M. o. yakutatensis. Records: Alaska (Hopla 1966; Holland 1985), Transbaikal and Russian Far East (Nikulina 1980; Medvedev et al. 2014). Prevalence: common in Alaska (Holland 1985), relatively rare in Russian Far East (Nikulina 1980; Medvedev et al. 2014).

Amphipsylla rossica Wagner, 1912

Distribution: Central and Eastern Europe, Middle East, West Siberian Plain, southern China (Skuratowicz 1967; Stanko et al. 2002; Balashov et al. 2007; Shenbrot et al. 2007; Kirillova and Kirillov 2018; Kotti 2018). Host range: M. arvalis and other Microtus voles. Record: Kostroma Region (Russia). Prevalence: often dominant (Krylov 1996).

Amphipsylla sibirica (Wagner 1898)

Distribution: Northern Europe, Lapland, Ural, West Siberian Plain, Central Siberian Plateau, Mongolia, Tian Shan (palaearctic subspecies A. sibirica sibirica, A. s. thoracicus, A. s. orientalis), Canada (nearctic A. s. pollionis); boreo-montane (Smit 1967; Vershinin et al. 2019). Host range: Myodes, Microtus and other rodents. Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), mentioned by many authors (Skuratowicz 1967; Novozhilova 1967; Holland 1985; Krasnov et al. 2010) without exact location.

Frontopsylla elata (Jordan et Rothschild, 1915)

Distribution: Caucasus, Mongolia, China, southern part of Russian Far East ((Lewis 1974b; Kotti 2018). Host range: Murinae and Cricetinae rodents (Litvinov and Litvinova 2003). Records and prevalence: Russia, mentioned as rare parasite by Krasnov et al. (2010).

Leptopsylla segnis (Schönherr, 1811)

Distribution: cosmopolitan. Host range: domestic mice M. musculus, often noted on other small rodents, birds, small predators (Skuratowicz 1967). Record and prevalence: Russia, mentioned as rare parasite by Krasnov (2010).

Leptopsylla taschenbergi (Wagner, 1898)

Distribution: Southern Europe, Kazakhstan, Lebanon, Algeria, Turkey (Medvedev et al. 2005; Kotti 2018). Host range: Apodemus mice, other small rodents. Record: southwestern Russia (Kirillova and Kirillov 2018).

Peromyscopsylla bidentata (Kolenati, 1860)

Syn. Leptopsylla bidentata Kolenati 1860

Distribution: Europe, western Asia, Altai Mts. (Skuratowicz 1967; Balashov et al. 2007). Host range: M. glareolus, other Microtinae (Ambros et al. 1985; Stanko et al. 2002), rarely Soricidae, mustelids. Records: Slovakia (Dudich 1985), Poland (Skuratowicz 1967; Bartkowska 1981; Karbowiak et al. 2022), Fennoscandia (Lundquist and Brinck-Lindroth 1990), Belarus (Kononova 1996), Komi Republik and Siberia (Novozhilova 1967), western Russia (Krylov 1996; Krasnov et al. 2010). Prevalence: Poland, mentioned as rare parasite (Skuratowicz 1967; Bartkowska 1981; Karbowiak et al. 2022), most often during cold months (Stanko 1988).

Peromyscopsylla ostsibirica (Scalon, 1936)

Syn: Leptopsylla ostsibirica Scalon, 1936

Distribution: northeastern Asia, Transbaikal, Yakutia, the Khabarovsk Krai, Primorskiy Territories, Alaska, Yakutia, Mongolia, China, Korea, Canada and northern states of USA (Smit 1967; Violovich 1963; (Lewis 1974b; Holland 1985; Kiefer et al. 2012; Vershinin et al. 2019). Host range: most frequently on M. oeconomus, also other rodents. Records: Mongolia (Smit 1967), Kamchatka (Violovich 1963), coast of the Sea of Okhotsk (Medvedev et al. 2014), Alaska (Holland 1985; Haas et al. 2012). Prevalence: 2–3 per host (Hopla 1966), more often in autumn (Haas et al. 2012; Vershinin et al. 2019).

Peromyscopsylla silvatica (Kolemati, 1863)

Syn. Leptopsylla silvatica Kolemati, 1863

Distribution: Central Europe, Scandinavia, northern Kazakhstan, West Siberian Plain, Central Siberian Plateau Novozhilova 1967; (Lewis 1974b; Balashov et al. 2007; Kotti 2018). Host range: Apodemus, Myodes, Microtus. Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), Poland (Skuratowicz 1967), Belarus (Savitsky and Kulnazarov 1988), Komi Republik and Siberia (Novozhilova 1967), Altai Mts. (Bogdanov and Yakimenko 2016; Korzikov et al. 2018).

Ctenophthalmidae

Catallagia dacenkoi Ioff, 1940

Distribution: Ural, Altai Mts., Yakutia, Transbaikal, Kamchatka, Mongolia (C. dacenkoi dacenkoi Ioff, 1940), northwestern Alaska, Canada (C. dacenkoi fulleri Holland, 1951), (Violovich 1963; Hopla 1966; Smit 1967; Haas 2012; Kiefer et al. 2012; Vershinin et al. 2019). Host range: microtid rodents, rarely other rodents and insectivores. Records: Komi Republic, Transbaikal, coast of the Sea of Okhotsk (Novozhilova 1967; Nikulina 1980; Medvedev et al. 2014), Alaska, Canada (Hopla 1966; Lewis and Haas 2001; Haas 2012). Prevalence: 1–2 specimens per host (Hopla 1966), more abundant during winter (Schwan and Nelson 1983).

Catallagia charlottensis (Baker, 1898)

Distribution: Alaska, Eastern Pacific coast (Holland 1963). Host range: Peromyscus keeni (Rhoads, 1894), M. rutilus. Record: Alaska (Haas 1982).

Catallagia striata Scalon, 1950

Distribution: Transbaikal, Amur and Primorskiy Region, China, Korea, Japan ((Lewis 1974a). Host range: Myodes genus. Record and prevalence: Magadan, Russia, noted as single specimens (Medvedev et al. 2014).

Ctenophthalmus agyrtes (Heller, 1896)

Distribution: Europe, Western Asia Skuratowicz 1967; (Lewis 1974a; Balashov et al. 2007). Host range: Apodemus mice, less common on voles, S. vulgaris (Bartkowska 1981; Ambros et al. 1985; Cyprich et al. 1999; Stanko et al. 2002), dormice and insectivores (Cyprich et al. 1992). Records: Poland (Skuratowicz 1967; Haitlinger 2015; Karbowiak et al. 2022), isolated populations of M. o. mehelyi in Danubian Lowland and Slovakia (Dudich 1985; Baláž and Zigová 2020). Prevalence: 88.9% (Karbowiak et al. 2022); dominant usually (Bartkowska 1981; Ambros et al. 1985).

Ctenophthalmus (Euctenophthalmus) assimilis (Taschenberg, 1880)

Distribution: Europe, West Siberian Plain, Altai Mts., Mongolia, Tian Shan (Skuratowicz 1967; Lewis 1974a; Vershinin et al. 2019). Host range: mole T. europaea, Microtus subterraneus (de Sélys-Longchamps, 1836), M. arvalis (Cyprich et al. 1976; Bartkowska 1981; Stanko et al. 2002), Sorex spp. (Haitlinger 1984b, 2015), rarely Gliridae (Cyprich et al. 1992). Records: eastern Poland (Zwolski 1960; Skuratowicz 1967; Haitlinger 2010; Karbowiak et al. 2022), isolated population of M. o. mehelyi in Danubian Lowland (Cyprich et al. 1984; Dudich 1985; Baláž and Zigová 2020), Belarus (Kononova 1996), western Russia (Korzikov et al. 2018), western Siberia (Krasnov et al. 2010), Altai Mts. (Bogdanov and Yakimenko 2016). Prevalence: 22.2% (Karbowiak et al. 2022); dominant flea species of root vole (Krasnov et al. 2010).

Ctenophthalmus bisoctodentatus Kolenati, 1863

Distribution: Europe, north to the Carpathian Mts. (Skuratowicz 1967; Balashov et al. 2007). Host range: T. europaea; in autumn can be found in other small mammals (Stanko 1988). Record and prevalence: Slovakia (Rosický 1957); Poland, noted as a rare parasite (Karbowiak et al. 2022).

Ctenophthalmus (Euctenophthalmus) congerer Rothschild, 1907

Distribution: southern zone of Europe, West Siberian Plain, Central Siberian Plateau excluding northern parts, China, Japan (Skuratowicz 1967; Kotti 2018). Host range: microtid voles, rarely other small mammals (Skuratowicz 1967). Record and prevalence: Poland, noted as rare parasite (Karbowiak et al. 2022).

Ctenophthalmus solutus Jordan et Rothschild, 1920

Distribution: Central and Southern Europe (Skuratowicz 1967). Host range: Apodemus (Cyprich et al. 1976; Stanko 1988), less frequently Microtus, Myodes, Gliridae (Cyprich et al. 1992; Mašán and Krištofík 1996; Stanko et al. 2002). Records: Poland, noted as a rare parasite (Karbowiak et al. 2022).

Ctenophthalmus (Euctenophthalmus) uncinatus (Wagner, 1898)

Distribution: Central and Eastern Europe north to the Carpathian Mts, West Siberian Plain; boreal species (Skuratowicz 1967). Host range: M. glareolus, A. flavicollis, Sorex spp. (Skuratowicz 1967; Bartkowska 1981; Krylov 1996). Records: Poland (Skuratowicz 1967; Karbowiak et al. 2022), Belarus (Savitsky and Kulnazarov 1988), Komi Republic and Siberia in Russia (Novozhilova 1967). Prevalence: dominant (Novozhilova 1967.

Epitedia wenmanni (Rothschild, 1904)

Distribution: Pacific coast of Canada and Alaska, Newfoundland, northeastern and eastern states of USA (Holland 1985). Host range: Peromyscus sp., Microtus sp., Myodes sp. Records: Alaska, Canada (Holland 1985). Prevalence: 1–2 per host (Hopla 1966).

Neopsylla acanthina Jordan et Rothschild, 1923

Distribution: West Siberian Plain, Central Siberian Plateau. It inhabits taiga and forest-steppe zone. Host range: Murinae and Microtinae rodents. Records: Magadan, Russia (Medvedev et al. 2014). Prevalence: as common parasite registered by Krasnov et al. (2010).

Rhadinopsylla accola Wagner, 1930

Distribution: Central Asia, Tibet, China (Tsai et al. 1978; Medvedev et al. 2005). Host range: Neodon sikimensis Horsfield, 1851, M. oeconomus, Urocricetus kamensis Satunin, 1903. Record: China (Tsai et al. 1978).

Rhadinopsylla integella Jordan and Rothschild, 1921

Distribution: Europe, Ural, southern parts of West Siberian Plain, Central Siberian Plateau and Russian Far East (Kotti 2018; Vershinin et al. 2019). Host range: Microtinae rodents, sporadically insectivores; nest parasite (Skuratowicz 1967; Stanko et al. 2002). Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), Belarus (Savitsky and Kulnazarov 1988); western Siberia, Komi Republic (Novozhilova 1967; Krasnov et al. 2010). Prevalence: numerous in the late autumn and winter (Skuratowicz 1967).

Hystrichopsyllidae

Corrodopsylla birulai (Ioff, 1928)

Syn. Doratopsylla birulai Ioff, 1928

Distribution: Scandinavia, western Russia, Tian Shan, Transbaikal, Khabarovsk Krai, Japan; Canada, Alaska; boreal species (Lewis 1974a; Kiryllova and Kiryllov 2018; Lundquist and Brinck-Lindroth 1990; Vershinin et al. 2019). Host range: insectivores, accidentally other small mammals (Krylov 1996; Medvedev et al. 2014). Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), Russia (Krylov 1996) Altai Mountains Mts. (Bogdanov and Yakimenko 2016).

Corrodopsylla curvata (Rothschild, 1915)

Syn: Doratopsylla curvata Rothschild, 1915

Distribution: Canada, Alaska, Caribbean subregion, Western America subregion, Mexico (Lewis 1974a; Haas 2012). Host range: B. brevicauda, as well Sorex, Microsorex, a number of long-tailed shrews, rarely rodents. Records: Alaska, Canada, Bering Sea coast, noted as rare parasite (Hopla 1966; Holland 1985; Haas 1982, 2012).

Doratopsylla dasycnema (Rothschild, 1897)

Distribution: Europe, West Siberian Plain (Skuratowicz 1967; (Lewis 1974a). Host range: Neomys, Sorex (Skuratowicz 1967; Cyprich et al. 1976; Bartkowska 1981; Stanko et al. 2002), also Microtus (Skuratowicz 1967), rarely Gliridae (Cyprich et al. 1992). Records: Poland (Karbowiak et al. 2022), Komi Republic (Novozhilova 1967).

Hystrichopsylla occidentalis Holland, 1985

Distribution: Alaska, Canada and Eastern Pacific coast to California (Holland 1963). Host range: Microtid rodents, insectivores. Records: Alaska (Campos and Stark 1979; Holland 1985).

Hystrichopsylla orientalis Smit, 1956

Distribution: Eastern Europe, on the east of middle part of Poland and Slovakia (Stanko 1988), Western Siberia, Komi Republic (Novozhilova 1967; Krasnov et al. 2010). Host range: Murinae, Microtinae (Stanko et al. 2002), less frequent Gliridae (Cyprich et al. 1992). Records: eastern parts of Poland (Haitlinger 2008, 2015; Karbowiak et al. 2022), Danubian Lowland (Baláž and Zigová 2020), Lithuania (Lipatova 2020), western Russia (Korzikov et al. 2018), Western Siberia, Komi Republic (Novozhilova 1967; Krasnov et al. 2010). Prevalence: 21.7%, one of dominant fleas (Novozhilova 1967).

Hystrichopsylla talpae (Curtis, 1826)

Distribution: Western Europe; on eastern border of geographic range occurs together with H. orientalis (Stanko 1988a). Host range: mole T. europaea, many small mammals, rodents and insectivores. Records: Poland (Kowalski et al. 2014; Haitlinger 2015), Slovakia (Cyprich 1984; Dudich 1985)

Palaeopsylla similis Dampf 1910

Distribution: Central and eastern Europe (Skuratowicz 1967). Host range: T. europaea, less frequently other insectivores, rarely A. flavicollis, M. glareolus (Bartkowska 1981; Stanko 1988). Record: Poland, noted as accidental parasite (Karbowiak et al. 2022).

Palaeopsylla soricis (Dale, 1878)

Distribution: Europe, Central Asia, Transbaikal, Mongolia, Tian Shan (Kiefer et al. 2012; Kotti 2018; Vershinin et al. 2019). Host range: Sorex, Neomys. Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), eastern Poland (Zwolski 1960; Skuratowicz 1967; Karbowiak et al. 2022), Russia (Novozhilova 1967; Krasnov et al. 2010). Prevalence: accidental (Zwolski 1960; Karbowiak et al. 2022).

Anoplura

Hoplopleura acanthopus (Burmeister, 1839)

Distribution: Europe, Asian part of Russia, Alaska, Canada, USA (Wegner 1966). Host range: Microtinae, less frequent Murinae, Soricidae, small carnivores (Wegner 1966; Cyprich et al. 1976; Haitlinger 1976, 2015; Krištofík and Dudich 2000). Records: Fennoscandia (Lundquist and Brinck-Lindroth 1990), Poland (Haitlinger 2015), Slovakia (Kováčik and Dudich 1990; Krištofík and Dudich 2000), Hungary (Vas et al. 2012), Belarus (Kononova 1996), Ob region and Transbaikal (Nikulina 1978; Starikov et al. 2019, 2021). Prevalence: 92.9% (Starikov et al. 2021).

Hoplopleura affinis (Burmeister, 1839)

Distribution: Europe, European part of Russia, Asia (Wegner 1966). Host range: Apodemus agrarius (Pallas, 1771), rarely other rodents (Haitlinger 1976; Balashov et al. 2007; Krištofík and Dudich 2000; Vas 2012). Record: Belarus (Savitsky and Kulnazarov 1988).

Hoplopleura edentula Fahrenholz, 1916

Distribution: Northern Hemisphere; boreo-alpine species (Wegner 1966). Host range: M. glareolus (Kohn and Štérba 1987; Balashov et al. 2007; Vas et al. 2012), less frequently other small mammals (Haitlinger 1976; Krištofík and Dudich 2000). Records: Fennoscandia (Lundquist and Brinck-Lindroth Lundquist and Brin), Belarus (Kononova 1996), Ob region (Starikov et al. 2019, 2021).

Polyplax alaskensis Ewing, 1927

Distribution: Alaska (Quai 1950). Host range: lemmings, voles. Record: mentioned by Durden and Musser (1994).

Polyplax borealis (Ferris, 1933)

Distribution: West Siberian Plain, Alaska, Western Canada; boreal species (Popov 1977; Medvedev 2009). Host range: A. terrestris, Myodes spp., Microtus spp., Phenacomys spp. (Popov 1977; Medvedev 2009). Records: Tiumen region (Popov 1977; Medvedev 2009).

Polyplax hannswrangeli Eichler, 1952

Distribution: Central and eastern Europe, West Siberian Plain, Transbaikal (Starikov et al. 2022). Host range: M. glareolus. Records: Ob region, Transbaikal, West Siberia (Nikulina 1978; Starikov et al. 2019, 2021, 2022).

Polyplax serrata (Burmeister, 1839)

Distribution: cosmopolitan (Wegner 1966). Host range: Apodemus, Mus, rarely microtid rodents (Wegner 1966; Kiewra and Modrzejewska 2005; Haitlinger 2008). Record: Belarus. Prevalence: rare (Savitsky and Kulnazarov 1988).

Summarising list of associated arthropods

The ectoparasites of M. oeconomus belong to the orders Acari (mites and ticks), Anoplura (sucking lice) and Siphonaptera (fleas). There are no records of parasites belonging to Coleoptera (beetles) and Diptera (flies), whose representatives can occur on other Microtus species (Timm 1985). The total list of related arthropods recorded in the entire area of root vole distribution includes eight species of ixodid ticks, 52 species of mites, 47 species of fleas and seven species of sucking lice; however, only 21 of them cover the whole occurrence range of the host. (Tables 1, 2, 3 and 4). Many of the on the list species are those which have only been recorded on M. oeconomus once, or are mentioned as parasites of this rodent without specifying the location. These are 30 species (two ticks, 12 mites, 11 fleas, three sucking lice), mostly specific to another rodent or with a wide range of hosts for which root vole may have been an accidental host. Their association with M. oeconomus needs confirmation. The exceptions are two species of Psorergates, described as ectoparasites of this rodent on the basis of a single observation, and never recorded again.

Table 1 The world list of mites associated with Microtus oeconomus. Classification after Krantz and Walter (2009)
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Table 2 The world list of fleas associated with Microtus oeconomus. Classification after Krasnov (2008)
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Table 3 The world list of sucking lice associated with Microtus oeconomus
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Table 4 Distribution of ectoparasitic arthropod species associated to M. oeconomus in zoogeographic regions
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As typical parasites of rodents, associated with voles, arthropods are classified into four taxonomic groups. The list of associated arthropods varies geographically. These are ixodid ticks, gamasid and chigger mites, fleas and sucking lice. The lifestyle of root vole also influences the parasite community – the preferred habitats of this species are wet fields and meadows as well as wet forests. It digs burrows and is able to build nests above the ground in bushes and clumps of grass and sedges (Pucek 1981).

Most of the recorded ectoparasites are species with a broad host spectrum, although species that attack small mammals - rodents and insectivores predominate. Three flea species are specific to M. oeconomus - they are the most common and most abundant on this host. These are M. walkeri in Europe, P. ostsibirica in Asia and North America, and M. calcarifer in the entire Holarctic zone. In addition, Psorergates oeconomi and P. neerlandicus mites were found only on M. oeconomus, although this is only a single report, not confirmed by further observations.

The remaining groups of arthropods include parasites typical to the genus - common on M. oeconomus and other species of the genus Microtus; on other small mammals they occur in low numbers. These are the tick D. reticulatus in Western Palearctic, the mite H. transiliensis and the flea M. taiganus in Eastern Palearctic, three mites and three flea species throughout the Palearctic, two flea, four mite and two sucking lice species throughout the Holarctic realm. In addition, there are one nearctic mite and two flea species found in Asia and North America (Tables 1, 2, 3 and 4).

Geographical distribution of individual species of arthropods associated with root vole

The division of the world into zoogeographic regions largely reflects the distribution of species, but it does not exactly match them. For publication purposes, the Western Palearctic, the Eastern Palearctic, the Palearctic as a whole, and the Nearctic are included. However, it should be remembered that the division of the parasitic species mentioned in the paper between these regions is in some cases very coarse. Few are beyond doubt, such as the C. bisoctodentatus flea, found only in Europe, or the E. wenmanni flea, found only on the American continent. It is problematic to classify the species inhabiting western and eastern Eurasia to the appropriate part of the zoogeographic regions. The arbitrary border between the Western and Eastern Palearctic is the Ural mountain range. The mountain range is convenient in determining the boundaries of zones on the map, but it does not always render precisely into the occurrence and spread of animals. Most species begin their range in Central or Eastern Europe, spread throughout Asia to the Pacific coast, or possibly from the Atlantic coast throughout Europe to Western Siberia Plain. In these cases, species that occur in Europe, extending no further than Western Siberia Plain, were considered to belong to the Western Palearctic, species found in Eastern Europe, and further found throughout Asia all the way to the Pacific, are considered as fauna of the Eastern Palearctic. The decisive factor was whether most of the range of this species is to the west or east of the Ural Mountains. The question of the horizontal division of Asia into zoogeographical realms has been omitted; except for a few cosmopolitan species, the ectoparasites associated with M. oeconomus do not occur south of the Himalayas, in the Oriental region.

The occurrence range of ectoparasites was considered due to the relationship with M. oeconomus. Therefore, cosmopolitan species occurring around the globe were considered to belong to the Holarctic region, along with others occurring in Europe, Asia and the North American continent.

In general, the dominant parasites of Palearctic and Nearctic root vole populations are either cosmopolitan or Palearctic species. The analysis of the geographical range of their occurrence indicates that most of them occur both in Europe and Asia. In the whole Holarctic realm - across Europe, Asia and Northern America - root voles share 13 species of mites, seven species of fleas, and three species of sucking lice. The species that occur in two continents are found mainly in the Palearctic region - Europe and Asia. They include species that are found throughout Eurasia, from the Atlantic coast, or at least from Central Europe, to the Pacific coast of Asia, or at least their range extends to the Central Siberian Highlands. These are three tick species, 16 mite species, seven flea species and two sucking lice species. Ectoparasites of root vole, occurring in Asia and the North American continent are only one tick species, two gamasid mite species, three flea species and one sucking louse species. Among parasites that occur only in the Western Palearctic, root voles harbour three tick species, 14 mite species, and 13 flea species. As mentioned above, most of these species exceed the Urals range. Two species of gamasid mites and five species of fleas are recorded only in Europe. In the Eastern Palearctic one species of ticks, four species of mites, and seven flea species are found. Three mite species, ten flea species and one sucking louse species have been found on root voles in Northern America only (Table 4).

It is obvious that throughout the wide range of M. oeconomus distribution, there is a large group of cosmopolitan ectoparasites, recorded from every place of occurrence of their host. This phenomenon can be linked to the late colonization of Northern America by the root vole around 55,000 years ago in the Pleistocene, while M. oeconomus fossils in Europe date back 125,000 years. Consequently, the allozymic, chromosomal and morphological variability between subspecies is less than on previous invaders (Lance and Cook 1998). The dominant parasites of the Palearctic and Nearctic vole populations are therefore cosmopolitan or Palearctic species. Many of the blood-sucking parasites that are characteristic of Nearctic rodents cannot be found anywhere outside this region. Holland (1963) emphasizes that many flea species are believed to have survived from the ancient Bering fauna, which apparently originated in the Palearctic. In general, nearctic forms are co-species with species found in Asia, and sometimes in Europe.

The most numerous group of M.oeconomus ectoparasites are species inhabiting the entire Palaearctic zone. The next numerous group are ectoparasites, the range of which covers the entire Holarctic realm - from Europe, through Asia to North America. Among them, there are cosmopolitan species, spread all over the world. The species belonging to the cosmopolitan group are the mites A. fahrenholzi, H. ambulans, E. stabularis, the fleas N. fasciatus, L. segnis, and the sucking louse P. serrata. These are polyxenic parasites, or species scattered all over the world with cosmopolitan hosts - especially rats and house mice. They comprise the L. segnis and N. fasciatus fleas, and the A. fahrenholzi mite. The mites H. amphibius and L. muris can be also included to this group; they are associated with A. terrestris, and spread to new areas with their host. They are not abundant on root voles, but due to low host specificity they attack them in the absence of suitable hosts.

Many of that group are boreal, boreo-montane or trans-Beringian species, not so much related to the typical environment of these landscapes, but to the polar climate: H. gudauricus, L. clethrionomydis, A. penicilliger, C. idius, C. indages, M. rectangulatus, A. marikovskii, A. sibirica, and C. birulai.

The least numerous is the group shared between Asia and America. There are only seven species - I. angustus, H. mandschuricus, L. multispinosus, Amphipsylla marikovskii, P. ostsibirica, C. dacenkoi, and P. borealis.

It is noteworthy that one tick species - Haemaphysalis concinna - has only been recorded in an isolated population of the root vole in southern Slovakia. In analogy, the fleas Epitedia spp. unique to voles on the American continent and many distinct boreal species of the genera Catallagia, Oropsylla and Corrodopsylla are not found in Asian and European vole populations.

It should be noted that many species of ectoparasitic arthropods have a much wider range of distribution than their known records on the root vole. This applies, for example, to wide-ranging arthropods such as the D. reticulatus tick, the P. kraepelini, H. nidi, H. hirsutus mites, and the M. turbidus, M. walkeri, N. fasciatus and C. agyrtes fleas. Known reports of their finding on root voles concern only the western area of their occurrence. There are also species often collected from root voles only in the eastern part of their range such as H. nidiformes, H. liponyssoides, H. soricis, and H. amphibius mites and the M. rectangulatus flea. At the moment it is not possible to say whether this is only the result of a lack of sufficient studies or whether they actually prefer other species of hosts spread in the range of their occurrence.

The nature of the associations between arthropods and root voles

Arthropods associated with rodents and insectivores formed several ecological groups of parasites given by their feeding behavior and degree of association with mammals. The first are obligatory parasites (OP), specialized and having a strong trophic relationship with the mammal, in many cases with a specific genus or species. They live mainly in the hair (parasites that inhabit the host) or in nests (parasites that inhabit the nests). Representatives of this group are ixodid ticks, sucking lice, adult fleas and many gamasid mites (Hirstionyssus, Laelaps). Temporary parasites may be included in this group as well, which feed on the host but spend most of their time in the host’s nest. Common examples are a few fleas and a few mesostigmatid mites.

Facultative parasites (FP) live independent of a host but may occasionally be parasitic. They can be found on the body of a mammal, but more often in their nests. This group includes species of mite genera such as Androlaelaps, Eulaelaps, Haemogamasus.

Obligate parasites are the most numerous group of parasitic arthropods associated with voles. These are all species of hard ticks - eight species, all sucking lice - seven species, fleas − 47 species and parasitic/facultative parasitic mites – about 40 species, most of which belong to Laelapidae, Trombiculidae, Myobiidae, Psorergatidae and Listrophoridae families. Most of the obligate parasites occur in the Palearctic region, the most numerous group of which are both in Asia and Europe. The range of a few parasites is limited to Western Palearctic (17 species, including 4 ticks, 9 mites, 13 fleas) or Asia (7 species including one tick, 2 mites, 3 fleas, one sucking louse species) only. Two flea species have a cosmopolitan range due to the wide distribution of their main hosts. Facultative parasites are a small group of 14 mite species belonging to Parasitidae and Laelapidae. They are species with a wide range, spanning the Palearctic and even the entire Northern Hemisphere. The large group of mites includes arthropods associated not with voles, but with their nests, as commensals or on the principle of synoikia - groups of nidicolous and edaphic species. The four species - Androlaelaps fahrenholzi, Eulaelaps stabularis, Nosopsyllus fasciatus, Leptopsylla segnis, have a cosmopolitan range. An interesting fact is the lack of recorded optional parasites and arthropods from the nidicolous and edaphic groups in the nearctic; however, it cannot be determined whether they do not actually exist, or whether they exist and have not been detected so far (Tables 1, 2 and 3).

In many cases it is difficult to classify several species or taxa into a particular ecologic group. Many mites have a wide spectrum of foraging behavior, they can be both predators and hematophages. Fleas, as adults, are obligatory blood feeding parasites, strongly associated with their hosts, while as larvae they are associated with nests, where they find favorable conditions for development, and at this stage of development they are saprobionts.

In the case of ticks and fleas, the nature of their parasitism usually follows the taxonomic order and their enumeration is not difficult. This is not the case for mites, as obligate and facultative hematophages or predators can be found in the same taxonomic group. An additional difficulty is the fact that some species are known only from the morphological description and nothing is known about their lifestyle, food, or the role they play in the root vole. Therefore, the classification of these species into the group of obligatory, facultative or commensal parasites is based on the principle of reference to related species - which of course carries the risk of error.

The prevalence of infestation and domination structure

The list of arthropod species associated with the root vole is quite extensive. Most of the reports, however, concern only finding the species on voles or in their nests. Compared to the species list, detailed data on the degree of ectoparasite infestation of voles are sparse and come from only a few sources. In many cases, authors noted the species as common or dominant parasite and give either detailed numbers nor the season of occurrence.

The dominant group of parasites is determined by the high frequency of infestation – usually above 10.0%, and the occurrence in all host populations in the geographical area. Since the occurrence of the parasite depends not only on the presence of the host, but also on some environmental factors, the dominant groups may be different in the European, Asian and American root vole populations. This is included in the literature records. The dominant external parasites of the root vole are hard ticks - larvae and nymphs. In Europe, such species are I. ricinus and D. reticulatus, their average prevalence is 11.0% and 14.0%, respectively (Karbowiak et al. 2022), but seasonally the prevalence can reach 75 to 100.0% (Kononova 1996; Karbowiak et al. 2022). In Asia, I. ricinus is absent and is replaced by I. persulcatus and I. pavlovskyi (Filippova 1977).

Among fleas, the dominant ectoparasites of the root vole in western Palearctic are M. walkeri, C. agyrtes, C. assimilis and H. orientalis, the mean prevalence of infestation is 31.6%, 26.5% and 20.6%, respectively (Karbowiak et al. 2022). In eastern Palearctic, M. rectangulatus is a common flea species on M. oeconomus - their mean prevalence is 19.6% (Novozhilova 1967). This species occurs in Europe, but it is rare and not listed on M. oeconomus (Skuratowicz 1967). The Asian species are N. acanthina, recognized as dominant in this rodent by Krasnov et al. (2010), M. calcarifer, and M. advenarius, noted on 28.3% and 20.2% of voles, respectively (Nikulina 1980).

Among the mites, H. arvalis is considered the dominant root vole parasite in Belarus and Russia (Edler and Mehl 1972), the recorded prevalence ranged from 10.0 to 17.9% of animals (Tagiltzev 1967; Savitsky and Kulnazarov 1988). The mite H. isabellinus was recorded among dominant species in western Siberia, the infestation was 76.4% (Tagiltzev 1967), and H. ambulans, L. agilis, L. hilaris were noted as dominants in Europe and Asia (Savitsky and Kulnazarov 1988; Polačiková 2013; Karbowiak et al. 2022).

In the entire Palearctic region, the dominant ectoparasite is the sucking louse H. acanthopus - listed on M. oeconomus in Poland, Belarus and Russia (Kononova 1996; Starikov et al. 2019; Karbowiak et al. 2022).

A common group of parasites are subdominants and their prevalence of infestation does not exceed 9.0%. Parasites with low host specificity and wide distribution mainly belong to this group. In Europe, such parasites are the M. turbidus flea, the H. nidi and H. ambulans mites (Karbowiak et al. 2022). The list of subdominant mites in the population of M. oeconomus in Belarus is provided by Savitsky and Kulnazarov (1988) - these are P. oudemansi, P. kraepelini, C. chiropterae, H. isabellinus, A. fahrenholzi, L. agilis, L. jettmari, and T. autumnalis. The dominant mite species inhabiting the nests of the root vole are H. ambulans and A. fahrenholzi (Edler and Mehl 1972; Whitaker et al. 2007; Krasnov et al. 2010; Bregetova 1956; Airoldi et al. 1989). In the Asiatic part of M. oeconomus occurrence range, the subdominants are fleas - C. uncinatus (Novozhilova 1967) and A. penicilliger, the prevalence of infestation was 9.8% (Nikulina 1980).

The variability of the parasitic fauna of different root vole populations is probably related to the differences in the historical development of the biotopes. These differences were also reflected in the different hydrological conditions, vegetation and level of diversity of small mammals. In addition, the contact and exchange of flea fauna with populations of small mammals living in various environmental conditions also plays an important role (Stanko 1994).

Seasonal variability is an issue to consider when describing the fauna of mammalian ectoparasites. Most species of ectoparasites change their population densities during the year or occur only seasonally, in certain months, and are absent in the rest of the year. An example of such a change in the seasonal abundance of ectoparasites is the population of root voles in the Baikal region described by Vershinin et al. (2019). In winter, gamasid mites dominate, and in summer, ixodid ticks. The fleas are most numerous in autumn, while sucking lice do not show any distinct fluctuations. In addition, seasonal changes in the number of parasitic mites are relatively rarely described, data can only be found in a few studies. For example, in Slovakia peak parasite numbers in Mus spicilegus Petényi, 1882 nests were found in December and declinen by April. In the group of nidicolous species, only a slight increase in numbers was observed in December, declining in April. Edaphic species had two population peaks, from December to February and in May (Várfalvyová et al. 2011). In Odessa, Ukraine, the peak number of gamasid mites on rodents was observed in autumn (Voljansky 1974). Some specific data were provided by Haitlinger (1988) for H. nidi and E. stabularis occurring on small mammals in Poland. Haemogamasus nidi has two population peaks - bigger in spring and smaller in autumn. Eulaelaps stabularis has one peak in summer. However, the dynamics may vary and depends on the host species. Sucking lice also tend to show seasonal dynamics in appearance. The average intensity of H. edentula infestation is low in spring and increase was observed in autumn (Haitlinger 1989).

Similar phenomena have also been described in the case of fleas. In the Białowieża Primeval Forest, C. agyrtes, M. turbidus and P. soricis are most abundant in summer, rarely in autumn, and absent in winter. Ctenophthalmus uncinatus is common in spring and summer, and declines in autumn. Peromyscopsylla bidentata occurs mainly in autumn and Rh. integella in winter (Lachmajer 1959).

Ticks are exhibiting the most rapid seasonal changes in incidence. On M. oeconomus, infestation by larvae and nymphs of ticks of the genera Ixodes and Dermacentor was observed (Karbowiak et al. 2022). Ticks are temporary parasites that are associated with the environment for a longer period of their life than with the host. The temperate climate has strong influence on their biology, seasonal dynamics of occurrence and peaks of activity, different for larvae, nymphs and adults (Nowak-Chmura 2013). This renders into noticeable seasonal changes in the host invasion.

Conclusions

The fauna of the root vole ectoparasites includes forms typical for small rodents - mites, ticks, fleas and sucking lice. The wide range of root vole occurrence cause a large variety of ectoparasites. Among the ectoparasites, there are local species found in specific zoogeographical regions, as well as widespread species found throughout the Holarctic. There is also a group of cosmopolitan species found all over the world.