A Review of Bat Fleas (Siphonaptera: Ischnopsyllidae) from Russia

Abstract

Eighteen flea species of four genera associated with bats (Chiroptera: Vespertilionidae, Rhinolophidae, Miniopteridae, Molossidae) are registered in Russia, based on a literature review as well as our own data. They are as follows: Myodopsylla trisellis, Ischnopsyllus (Ischnopsyllus) dolosus, Ischnopsyllus (I.) elongatus, Ischnopsyllus (I.) intermedius, Ischnopsyllus (I.) plumatus, Ischnopsyllus (I.) needhami, Ischnopsyllus (I.) obscurus, Ischnopsyllus (I.) octactenus, Ischnopsyllus (I.) simplex, Ischnopsyllus (I.) variabilis, Ischnopsyllus (Hexactenopsylla) hexactenus, Ischnopsyllus (H.) petropolitanus, Ischnopsyllus (H.) ussuriensis, Ischnopsyllus (H.) comans, Nycteridopsylla pentactena, Nycteridopsylla longiceps, Nycteridopsylla eusarca, Rhinolophopsylla unipectinata unipectinata. Ischnopsyllus (I.) elongatus and Ischnopsyllus (I.) octactenus were recorded in Kaluga Region and Vladimir Region for the first time. Ischnopsyllus (I.) variabilis in Kaluga Region is a newly documented find. Studied bat flea fauna exhibits a distinctly Western Palearctic appearance.

1. Introduction

The family Ischnopsyllidae comprises 122 species across 20 genera within two subfamilies—Ischnopsyllinae Wahlgren, 1907 and Thaumapsyllinae Jordan, 1947—representing approximately 6% of the order’s total diversity [1]. Approximately 15% of bat species are recorded as hosts of flea family Ischnopsyllidae. This relatively low percentage partly reflects the limited study of the group, as researchers have traditionally focused on flea taxa of greater epidemiological significance. It should also be noted that regional faunas have been studied unevenly. The most comprehensive data are available for the Palearctic and Nearctic regions, while the flea faunas of tropical areas remain comparatively under-documented [1,2].

The relatively low percentage of bat species hosting fleas primarily indicates that the parasitic potential of this insect group is limited by the habitat conditions of the host species. The relatively small percentage of bat species that are hosts of fleas indicates, first of all, that the parasitic capabilities of this group of insects are limited by the habitat conditions of the hosts. Analysis suggests that the presence of bat fleas is influenced by several key factors: (1) the tendency of bats to form large aggregations; (2) fidelity of bat colonies to specific roosts and their reuse year after year; (3) the presence and stability of the necessary microclimatic conditions (temperature and humidity) within shelters; and (4) the capacity of newly emerged adult fleas to access their hosts [1].

History of Research on Fleas of the Family Ischnopsyllidae in Russia

Some of the earliest studies of bat fleas in the territories of the Russian Empire and later the Soviet Union were conducted by Yu. N. Wagner [3,4,5], who made numerous discoveries and redescriptions of species spanning the territory from Crimea to the Far East, and by A. Dampf [6] in the Caucasus. Yu. N. Wagner also compiled one of the earliest catalogues of Palearctic fleas [5], which included several species from three genera of bat fleas.

Data on the distribution of bat fleas across various regions of the USSR—such as Eastern Siberia, the Far East, Central Asia, and the Caucasus—along with descriptions of several new species, are provided in the studies of I.G. Ioff and co-authors [7,8,9,10,11] and O.I. Skalon [12,13].

Findings of bat fleas in Dauria were described by I.F. Zhovtiy and co-authors [14]. A few decades later, Labunets and Degtyareva [15] published a comprehensive summary of bat fleas in the North Caucasus.

The epidemiological significance of bat fleas was explored in the studies of V.V. Kucheruk [16], V.M. Zhdanov and D.K. Lvov [17], and Medical Theriology (Ed. V.V. Kucheruk) [18].

Sergei G. Medvedev [19,20,21,22,23,24] summarized data on the systematics and fauna of Ischnopsyllidae fleas in various regions of the former USSR. This includes the Baltics and the north-west of Russia [25,26], Kazakhstan and Central Asia [27,28], as well as the Far East [24]. He also investigated parasite–host relationships within bats [29] and conducted detailed studies on the morphology of Ischnopsyllidae [30,31,32]. In 2010, research on the ectoparasitic fauna of bats in the Urals was initiated [33,34]. However, information on several regions—particularly Siberia—was either missing or significantly outdated. Moreover, changes in host status necessitated a revision of data concerning parasite–host relationships in the Eastern Palearctic, which we undertook for certain species [35,36,37,38].

Taxonomy of the family Ischnopsyllidae

A characteristic feature of the host–parasite relationship between fleas and bats is the uneven distribution of Ischnopsyllidae taxa across the order Chiroptera. We consider the classical division of bats into two suborders—fruit bats (Megachiroptera) and mostly insectivorous bats (Microchiroptera)—to be more appropriate for fleas research than the modern classification into Yangochiroptera and Yinpterochiroptera. Fleas of the genus Thaumapsylla, comprising four known species, infest fruit bats. Of the 16 families belonging to the second suborder—Microchiroptera—fleas have been found on 10. They are absent from certain small, endemic families, each comprising only one or two bat species. These include, in particular, the families Mormoopidae, Furipteridae, Natalidae, and Thyropteridae, which are endemic to South America, as well as Craseonycteridae and Myzopodidae, which are restricted to the African fauna.

The vast majority of species of the family Ischnopsyllidae infest bats of the families Vespertilionidae and Molossidae. Current data suggest that fleas of this family are mainly associated with a relatively narrow group of hosts within the subfamily Vespertilioninae, including various species of barbastelles, long-eared bats, mouse-eared bats, pipistrelles, and noctules [1]. Within the territory of the former USSR, four genera of Ischnopsyllidae are currently known: Myodopsylla, Ischnopsyllus, Nycteridopsylla, and Rhinolophopsylla [39]. The most frequently reported hosts of various flea species are mouse-eared bats (Myotis), one of the most ancient bat groups, dating back to the Middle Oligocene [40]. However, they serve as specific hosts only for the genus Myodopsylla.

In our collections, the family Ischnopsyllidae is represented by four genera: Myodopsylla, Ischnopsyllus, Nycteridopsylla, and Rhinolophopsylla. A total of 581 flea specimens belonging to 18 species were collected.

2. Materials and Methods

Bats were collected using mist nets placed near roosting sites across 48 localities in Russia (Figure 1,

Table 1. List of collection localities and bat species sampled between 2001 and 2020. Region codes correspond to those shown in Figure 1.

№	Locality Name	Coordinates
I. Kaliningrad Region
1.	Guryevsk municipal District, Bolshoe Isakovo Settlement, Fort № 1 ‘Steinz’	54°39′ N 20°31′ E
2.	Central District, Fort № 5 ‘Friedrich Wilhelm III’	54°45′ N 20°26′ E
3.	Leningradsky District, Fort № 3 ‘Friedrich III’	54°45′ N 20°32′ E
4.	Guryevsk municipal District, Maloe Vasilkovo Settlement, Fort № 2 ‘Bronzart’	54°44′ N 20°36′ E
II. Leningrad Region
5.	Volkhovsky District, Tanechkina Cave	60°00′ N 32°18′ E
III. Vologda Region
6.	Darwin Nature Reserve, Vauch Cordon, Losha River	58°35′ N 37°30′ E
7.	Darwin Nature Reserve, Netecha River	58°34′ N 37°33′ E
8.	Darwin Nature Reserve, Osinovik Cordon	58°37′ N 37°46′ E
IV. Tver’ Region
9.	Staritsky District, Ledyanaya Cave	56°34′ N 34°59′ E
V. Kaluga Region
12.	Kozelsky District, Optina Pustyn’ Village, pond on the Zhelezenka River ‘Valley of Love’	54°03′ N 35°51′ E
13.	Kozelsky District, Optina Pustyn’ Village, pond at the Optina Pustyn’ Monastery near the skete and along the walls	54°03′ N 35°50′ E
14.	Kozelsky District, Nizhnie Pryski, Zhizdra River floodplain, Gorozhenoe Lake	54°05′ N 35°53′ E
15.	Kozelsky District, Berezichsky Glass Factory, near the house	53°57′ N 35°49′ E
16.	Kozelsky District, Berezichsky Glass Factory, lake shore	53°58′ N 35°48′ E
17.	Kozelsky District, Dmitrovsky, pond in broad-leaved forest near the Chechik River	53°56′ N 35°48′ E
18.	Kozelsky District, Chernysheno Village, pond	53°48′ N 35°47′ E
19.	Kozelsky District, Volosovo-Zvyagino Village, pond in spruce-broad-leaved forest	53°54′ N 35°45′ E
20.	Kozelsky District, Volosovo-Zvyagino Village, pond	53°53′ N 35°46′ E
21.	Kozelsky District, Poloshkovo Village, automobile bridge across the Serene River	54°8′ N 35°52′ E
22.	Peremyshlsky District, Ilyinskoye Settlement, floodplain of Bolshoe Lake	54°12′ N 36°03′ E
23.	Peremyshlsky District, Kaluga experimental agricultural station, ponds near the Vyssa River	54°25′ N 36°04′ E
24.	Peremyshlsky District, Vorotynsk Town, floodplain of the Vyssa River	54°25′ N 36°02′ E
25.	Dzerzhinsky District, Luzhnoe Settlement, pond on the field	54°41′ N 36°44′ E
26.	Dzerzhinsky District, Shenyano-Sloboda Village, near houses	54°46′ N 35°54′ E
27.	Dzerzhinsky District, Shenyano-Sloboda Village, pond near the highway	54°44′ N 35°54′ E
28.	Dzerzhinsky District, Rudnya, dam on the Rudnitsa River	54°39′ N 35°53′ E
29.	Dzerzhinsky District, Novaya Zhizn’ Village, dam on the road	54°41′ N 35°49′ E
30.	Yukhnovsky District, Tents, pond bank	54°44′ N 35°22′ E
VI. Vladimir Region
10.	Aleshunino Village	55°49′ N 42°20′ E
11.	Nature Reserve ‘Dyukinsky’	56°00′ N 41°03′ E
VII. Krasnodar Territory
40.	Adler district of Sochi City, Akhshtyrskaya Cave	43°31′ N 40°00′ E
VIII. Dagestan Republic
43.	Yangiyurt State Nature Reserve, Shaitan-Kazak Settlement, Shaitan-Kazak Lake	43°19′ N 46°56′ E
44.	Suleiman-Stalsky district, Shurdere stream, surroundings of Sovetskoye Settlement	41°45′ N 48°17′ E
45.	Akushin district, Verkhnie Mulyobki Settlement	42°19′ N 47°31′ E
46.	Samurskiy National Park, Platan 800 years	41°52′ N 48°32′ E
IX. Astrakhan’ Region
41.	Astrakhan Order of the Red Banner of Labor State Nature Biosphere Reserve, Damchik Settlement	46°18′ N 49°00′ E
42.	Volodarsky District, Left Bank of Obzhorova River	46°18′ N 48°59′ E
X. Penza Region
31.	Right Bank of Surskiy Reservoir, Shemysheysky District, Research Station of Penza State University	52°58′ N 45°21′ E
XI. Mordovia Republic
32.	Ichalkovsky District, Bandasevsky Cordon tract, Mitryashka Lake	54°44′ N 45°30′ E
XII. Samara Region
33.	Nature Reserve ‘Samarskaya Luka’	53°18′ N; 49°49′ E
34.	Zhiguli State Nature Reserve, Solnechnaya Polyana Settlement, Volga Coast, Rizhskiy beach	53°26′ N 49°54′ E
35.	Zhiguli Nature Reserve, Solnechnaya Polyana Settlement, Boarding school № 3	53°25′ N 49°55′ E
36.	Zhiguli State Nature Reserve, Solnechnaya Polyana Settlement, Vremena Goda recreation	53°26′ N 49°55′ E
37.	Zhiguli State Nature Reserve, forestry, Bear Grotto	53°23′ N 49°55′ E
38.	Zhiguli State Nature Reserve, Temple of Nature Ecological walking route	53°24′ N 49°55′ E
39.	Zhiguli State Nature Reserve, Shiryaevo Settlement, Mount Popova	53°25′ N 50°0′ E
XIII. Tyumen Region
47.	Tyumen City	57°09′ N 65°32′ E
XIV. Altai Territory
48.	Salair National Park, Ionikha Cordon	53°33′ N 86°07′ E

). After capture, species identification was based on morphological characteristics following the taxonomic descriptions provided by Ditz et al. [41]. Bat classification and nomenclature follow [42].

Specifically, all specimens of Daubenton’s bat, Myotis daubentonii (Kuhl) (sensu lato), from regions east of the Ob River within the Khanty-Mansi Autonomous Region and the Ob-Irtysh interfluve, were identified as the eastern water bat, M. petax Hollister [43,44]. Myotis mystacinus (Kuhl) from Central Asia and M. aurascens Kuzyakin were considered as junior synonyms of David’s myotis Myotis davidii (Peters) [45]. Myotis mystacinus (Kuhl) from Central Asia and M. aurascens Kuzyakin were treated as junior synonyms of David’s myotis, Myotis davidii (Peters) [45]. Small mouse-eared bats of the M. brandtii s.l. (including M. sibiricus) and brown long-eared bats, Plecotus auritus (Linnaeus), occurring east of West Altai and the Ob River, were identified as the Siberian bat, M. sibiricus Kastschenko, and Ognev’s long-eared bat, Pl. ognevi Kishida, respectively [46,47]. Specimens of Natterer’s bat, M. nattereri (Kuhl) (sensu lato), from the Baikal Region and eastern Russia were assigned to the Amur bat, M. bombinus Thomas [46,47,48]. Long-fingered bats, M. capaccinii (Bonaparte) (sensu lato), from the Russian Far East were reclassified as eastern long-fingered bats, M. macrodactylus (Temminck) [49,50]. All individuals of the greater tube-nosed bat, Murina leucogaster Milne-Edwards (sensu lato), from Russia were identified as the Siberian tube-nosed bat, Mu. hilgendorfi (Peters). Lastly, specimens of Schreibers’ bat, Miniopterus schreibersii (Kuhl) (sensu lato), from eastern Russia were reclassified as the eastern bent-wing bat, Min. fuliginosus (Hodgson) [42,44,51,52].

The body parts of all captured bats—including the face, back, tail, wings, ears, and uropatagium—were visually inspected for ectoparasites using an LED headlamp. All ectoparasites collected from each individual bat were removed with forceps and placed into a single vial containing 95% ethanol. Subsequently, the samples were transferred to new vials with 70% ethanol and transported to the laboratory for mounting and identification. Flea specimens were cleared in 5% KOH for 24 h, rinsed in distilled water, and mounted on microscope slides using Faure-Berlese’s or Canada balsam mounting medium [53]. The slides were deposited in the Zoological Institute Russian Academy of Science (Saint Petersburg), FBUZ Center for Hygiene and Epidemiology (Kaluga City), and Penza State University (Penza City).

Morphological identification was performed following the keys of Hopkins and Rothschild [54] and Medvedev [55]. After ectoparasite collection, all bats were identified morphologically and released [41]. Photographs were taken using a Nexcope NE620 microscope (manufactured in Ningbo, China). Visualization of flea–host relationships was performed using the ‘bipartite’ package in R version 4.3.4 [56] (Figure 2). The number of publications reporting a particular flea species infesting a bat host, was used as a background for constructing the bipartite graph.

Abbreviations considered in the text: Brit. Mus. (Nat. Hist.)—British Museum (Natural History) (London, England), Hamb. Zool. Mus.—Hamburg Zoological Institute and Museum (Hamburg, Germany), ZIN RAS—Zoological Institute of the Russian Academy of Science (Saint Petersburg, Russia).

3. Results

The annotated species list is presented below.

Genus Myodopsylla Jordan et Rothschild, 1911

This genus is represented in the Palearctic by a single species—Myodopsylla trisellis Jordan, 1929.

Myodopsylla trisellis Jordan, 1929 (Figure 3)

(=Myodopsylloides rossica Markova, 1938).

Type material. Holotype, ♂, allotype ♀, paratypes—3♂♂, 4♀♀ ‘Charithun’, Nunjiang (Mergen) National Park, Pipistrellus sp., VI 1928 (H. Jettmar), deposited in Brit.Mus. (Nat.Hist.).

Material: ♂ ex M. dasycneme (02 IV 2023) from Tanechkina Cave, leg. A.L. Viskontene; ♂ ex P. nathusii (01 VII 2024), 40 ♀♀, 29 ♂♂ ex M. dasycneme (30 VI–04 VII 2024) from Darwin Nature Reserve, leg. A.L. Viskontene, O.A. Shapkin; ♀ ex M. dasycneme from Ledyanaya Cave 10 XI 2024, leg. E.A. Vinogradova; ♀ ex M. brandtii, from Volosovo-Zvyagino Village, 18 VII 2021, leg. V.A. Korzikov, A.V. Rogulenko; ♀ ex M. mystacinus, 6 VIII 2021, from Tents Village, leg. V.A. Korzikov, A.V. Rogulenko; ♂ ex M. brandtii, from Chernysheno Village, 5 VII 2023, leg. V.A. Korzikov, F. Bobachev; ♀ ex M. dasycneme, from Novaya Zhizn’ Village, 10 VII 2024, leg. V.A. Korzikov, F. Bobachev; ♀ ex M. brandtii (29 III 2019), ♀ ex M. brandtii (20 VII 2019), ♀ ex M. dasycneme (3 XII 2021) from Samarskaya Luka National Park, leg. D.G. Smirnov, M.S. Malyavina; ♀ ex E. nilssonii from Tyumen City, 27 VIII 2022, leg. O.L. Orlov, M.V. Orlova; 2 ♀♀ ex M. brandtii from Tyumen City, 8 VIII 2023, leg. O.L. Orlov, M.V. Orlova; ♀, ♂ ex M. dasycneme from Nature Reserve ‘Dyukinsky’, 11 IX 2024, leg. A.V. Pavlov, Y.A. Bykov; 2 ♀♀ ex Myotis brandtii from Nature Reserve ‘Dyukinsky’, 11 IX 2024, leg. A.V. Pavlov, Y.A. Bykov; ♀ ex M. dasycneme from Ledyanaya Cave 10 XI 2024, leg. E.A. Vinogradova; 4 ♀♀, ♂ ex M. dasycneme, 3♀♀, ♂ ex M. brandtii, ♂ ex M. daubentonii (09 X 2022), ♀, ♂ ex M. dasycneme (02 IV 2023) from Tanechkina Cave, leg. A.L. Viskontene; 6 ♀♀, ♂ ex M. sibiricus (15–17 VI 2024) Salair National Park, Ionikha Cordon leg. I.G. Baeva.

Range: Eastern Palearctic up to Finland in the west [57,58,59,60,61]. In the Western Palearctic, M. trisellis is absent (its northwestern border runs through the territory of the Baltic States), which may indicate the penetration of the species from North America through Beringia (this assumption is also confirmed by the fact that the remaining species of the genus Myodopsylla are found only in North and South America) [22].

Findings in Russia: Moscow Region [10,61], Kaluga Region [62] (this article), Voronezh Region [61], Saratov Region [22,63], Samara Region (this article), Udmurtian Republic [64], Perm Region [64], Sverdlovsk Region [64], Chelyabinsk Region [65], Tyumen Region [65], Khanty-Mansi Autonomous Area [66,67], Altai Territory [67] (this article), Novosibirsk Region [22,36], Republic of Khakassia [38], Kemerovo Region [35], Krasnoyarsk Territory [22], Republic of Sakha (Yakutia) [68], Republic of Tuva [37], Irkutsk Region [10,13,22,61], Buryatia Republic [38], Trans-Baikal Territory [22], Khabarovsk Territory [28], Magadan Territory [22,28], Primorskiy Territory [28], Kamchatka Territory [22,28], Povolzhie (Volga Region) without specification [10,13,61], Eastern part of Russian Plain’ without specification [69], Volga-Kama region without specification [70].

Hosts: Myotis blythii [65], M. dasycneme [19,24,33,65,71,72,73] (this article), M. davidii [65], M. daubentonii [24,33,65,73], M. brandtii [24,28,33,71,73,74] (this article), M. mystacinus [22,27,57,71] (this article), M. ikonnikovi [28], M. nattereri [22,24], M. sibiricus [38]; as M. gracilis—[75,76,77], M. petax [74]; as M. daubentonii—[28,33], Pipistrellus nathusii [22], P. pygmaeus (this article, new record), E. nilssonii [24,59] (this article), V. murinus [22,65], Plecotus ognevi (as Pl. auritus)[28], Mur. hilgendorfi [65].

$$

Genus Ischnopsyllus Westwood, 1833,

Subgenus Ischnopsyllus Westwood, 1833,

Ischnopsyllus (Ischnopsyllus) dolosus Dampf, 1912

=Ischnopsyllus teres Jordan, 1929.

Type material. The location of the type specimens of the senior synonym is unknown. The lectotype of I. teres, ♂, labeled ‘Caucasus’, Myotis sp., VIII1925 (Montague Clark), is housed in the Brit. Mus. (Nat. Hist.) [19,54].

Range: This species is found in the Caucasus and adjacent regions (including Iran—[45]). It was subsequently collected in North Ossetia and other parts of the Caucasus [10,16,55,76,77].

Findings in Russia. Kabardino-Balkarian Republic [7], Northern Ossetia—Alania Republic [16], Karachayevo-Circassian Republic [16], Republic of Dagestan [16].

Hosts. Myotis blythii [16,45].

Doubtful records: M. mystacinus (Northern Ossetia, Karachaevo-Circassian Republic, Republic of Dagestan [16]), M. brandtii (Turkey [78]).

Note. Sources from the 20th century (e.g., [16]) reported findings of Ischnopsyllus (I.) dolosus attributed to M. mystacinus. However, the authors did not distinguish between M. mystacinus and M. davidii, both of which occur in the Northern Caucasus. The record of M. brandtii from Turkey [78] was later shown to refer to a species complex involving M. brandtii, M. mystacinus, and M. davidii [79] Identification of these bats is challenging and should not always be accepted without confirmation in non-specialized studies.

Ischnopsyllus (I.) elongatus (Curtis 1832)

(=Ceratophyllus elongatus Curtis, 1832;

=Ceratophyllus elongatus Rothschild, 1898;

=Ceratopsylla subobscura Wagner, 1898;

=Ceratopsyllus suboscura Wagner, 1898).

Type material. Types are probably lost. The holotype of Ceratopsyllus subobscura is missing; a paratype, collected in Khrenovsky, Voronezh Region, from a bat in 1896 (A. Silantyev), is housed in Hamb.Zool.Mus.

New data: ♀ ex Nyctalus noctula and 2 ♀♀ ex N. lasiopterus from Samarskaya Luka National Park, VI 2006, leg. D. G. Smirnov; ♀ ex N. noctula from Akhshtyrskaya Cave, VIII 2001, leg. D. G. Smirnov; ♀ ex M. dasycneme from Kozelsky District, Optina Pustyn’, pond on the Zhelezenka River “Dolina Liubvi”, 5 VII 2022, leg. V.A. Korzikov, S.E. Karpukhin; ♀, 2 ♂♂ ex Nyctalus noctula from Aleshunino Village, 14 VIII 2024, leg. A.V. Pavlov, Y.A. Bykov; ♀ ex N. leisleri from Aleshunino Village, 21 VIII 2022, leg. A.V. Pavlov, Y.A. Bykov; 2♀♀ ex Plecotus auritus from Aleshunino Village, 21 VIII 2022, leg. A.V. Pavlov, Y.A. Bykov.

Range: A Palearctic subboreal species. In Europe, its range extends northwest to England and southwest to northern Italy. In the northern part of its distribution, the species is found in Great Britain, Denmark, Sweden, Germany, Latvia, and the Middle Volga Region. Southern records include Bulgaria, the northern Caucasus, and northern Iran, Republic of Uzbekistan [24,25,60,76,80,81,82,83,84,85]. The eastern part of the range is poorly studied, but occurrences have been reported from several localities in China and Japan [86,87].

Findings in Russia. Pskov Region [25], Moscow Region [54,88], Kaluga Region (this article, new record), Kursk Region [10], Voronezh Region [54], Vladimir Region (this article, new record), Saratov Region [63,89], Samara Region (this article, new record), Rostov Region [16,90,91], Krasnodar Territory [16], Republic of Adygeya [16], Stavropol Territory [16], Eastern part of Russian Plain’ without specification [69].

Hosts. Nyctalus noctula [19,24,25,63] (this article), N. lasiopterus [16,92] (this article), N. leisleri [93,94] (this article), Vespertilio murinus [19,54], E. serotinus [19,54], Pipistrellus nathusii [25], P. pipistrellus s.l. [19], Myotis dasycneme (this article, new record), M. daubentonii [19], M. myotis [19], M. brandtii [95], M. mystacinus [83], B. barbastellus [19], Rhinolophus hipposideros (Bechstein, 1800) [16], Pl. auritus (this article, new record).

Note. According to the literature, this is a monoxenous species, with the principal host in Europe being the common noctule, Nyctalus noctula, whose range does not extend to China. However, it is more likely that I. elongatus is an oligoxenous ectoparasite capable of parasitizing various species of the genus Nyctalus, including the birdlike noctule, Nyctalus aviator (Thomas, 1911). This broader host range may explain its Palearctic distribution.

Ischnopsyllus (I.) intermedius (Rothschild, 1898) (Figure 4)

(=Ceratopsylla intermedius Rothschild, 1898;

=Ceratopsylla intermedius Rothschild, 1898;

=Ceratopsylla wagneri Kohaut, 1903;

=Ischnopsyllus schmitzi Oudemans, 1909).

Type material. Holotype, ♂, paratypes 2 ♂♂, 1 ♀, Yalding, Kent, UK, Eptesicus serotinus (as Scotophilus serotinus), 8 VIII 1897, 25 V 1898, 23 VI 1900 (W.R.O. Grant and S. Ryde), deposited in Brit.Mus. (Nat.Hist.).

New data: ♀ ex Vespertilio murinus from Kozelsky District, Volosovo-Zvyagino Village, 13 VII 2021, leg. V.A. Korzikov, A.V. Rogulenko; 2 ♀♀ ex N. noctula (VII 2018), 6 ♀♀, ♂ ex N. noctula (VII 2019), ♀ ex E. nilssonii (VII 2019), 2 ♀♀ ex E. serotinus (20 VII 2019), ♀ ex M. dasycneme (22 VII 2019), ♀ ex N. lasiopterus (23 VII 2019), ♀, 2 ♂♂ ex N. leisleri (VII 2019), ♂ ex V. murinus (14 VII 2018) from Samarskaya Luka National Park, leg. D.G. Smirnov; ♀, ♂ ex Pip. pygmaeus from Shemysheysky District, Research Station of Penza State University, leg. D.G. Smirnov, M.S. Malyavina; ♂ ex M. dasycneme from Kozelsky District, Optina Pustyn’, pond near Optina Pustyn Monastery near the skete and along the walls, 10 VII 2022, leg. V.A. Korzikov, A.V. Rogulenko; ♂ ex N. leisleri from Peremyshlsky District, Ilyinskoye Settlement, floodplain of Bolshoe Lake, 11 VII 2023, leg. V.A. Korzikov, F. Bobachev; ♀ ex V. murinus Dzerzhinsky District, Luzhnoe settlement, pond on the field, 8 VII 2024, leg. V.A. Korzikov, F. Bobachev; 3 ♀♀, 2 ♂♂ ex V. murinus from Kaluga Region Dzerzhinsky District, Shenyano-Sloboda Village, near houses, 9 VII 2024, leg. V.A. Korzikov, F. Bobachev; 5 ♀♀, 2 ♂♂ ex N. noctula (V 2018), ♀ ex Pip. kuhlii (VIII 2019) from Astrakhan Biosphere Reserve, leg. D.G. Smirnov; ♀ ex N. noctula (V 2019) from Yangiyurt State Nature Reserve, Shaitan-Kazak settlement, Shaitan-Kazak Lake, leg. D.G. Smirnov.

Range: Western Palearctic species: The range extends from the Azores to Ustyurt. The northern boundary runs along southern Great Britain, through Denmark, Sweden, Estonia, and the central part of European Russia. The southern boundary is defined by records from northern Italy, Bulgaria, the Crimean Peninsula, Transcaucasia, Turkey, Iran, and Algeria [10,24,35,60,76,78,81,82,83,84,85,96,97,98,99].

Findings in Russia. Republic of Crimea [100], Kaluga Region [62] (this article), Voronezh Region [88], Kursk Region [88], Saratov Region [89], Ulyanovsk Region [101], Samara Region [102], Karachay-Cherkessia Republic [16], Rostov Region, Stavropol’ Territory, Krasnodar Territory, Northern Osetia—Alania [16].

Hosts. E. serotinus [16,19], (this article), E. nilssonii [19,24,103] (this article), E. isabellinus [104], Pipistrellus pipistrellus [16,19], Pip. nathusii [19,24], Pip. pygmaeus (this article, new record), Pip. kuhlii [100] (this article), Myotis myotis [19,100], M. daubentonii [19], Myotis dasycneme [19,23,24] (this article), M. blythii [103], M. mystacinus [19]; Nyctalus noctula [16,19,102] (this article), N. lasiopterus (this article, new record), N. azoreum [54], N. leisleri [19,54,93,102] (this article), Hypsugo savii [65], Plecotus auritus [19,103], Barbastella barbastellus [19,103], V. murinus [19,24] (this article), Rhinolophus hipposideros [19,103], Rh. ferrumequinum [19]. Doubtful record: M. brandtii (Turkey—[78]) (see note to Ischnopsyllus (I.) dolosus).

Note. Ischnopsyllus (I.) intermedius is most likely a polyxenous species: In the northern part of its range, the principal host is the pond bat (Myotis dasycneme), while in the southern part it is the serotine bat (Eptesicus serotinus) and the common pipistrelle (Pipistrellus pipistrellus (Leach)) [23,85].

In this article, we consider the record of Ischnopsyllus (I.) intermedius on Pipistrellus pygmaeus to be new, as the previous source [19] did not distinguish between Pipistrellus pipistrellus and P. pygmaeus.

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Ischnopsyllus (I.) plumatus Ioff, 1946 (Figure 5)

Type material. Lectotype, ♂, paralectotypes, ♂, 2 ♀♀ ex Myotis myotis (?) from Kazakhstan, Djambul Region, Voznesenovka Settlement, 5 VII 1929 (leg. N.I. Kalabukhov), deposited in Stavropol Research Anti-Plague Institute, Stavropol, Russia [91].

Material includes 2 ♀♀ ex Eptesicus serotinus (20 VII 2019) from Samarskaya Luka National Park, leg. D.G. Smirnov, ♀ ex Nyctalus noctula (11 VII 2018) from Zhiguli State Nature Reserve, Solnechnaya Polyana Settlement, leg. D.G. Smirnov, ♀ ex N. lasiopterus (23 VII 2019) from Zhiguli State Nature Reserve, Solnechnaya Polyana Settlement, leg. D.G. Smirnov.

Range: Russia (European part—[89,102]), Republic of Kazakhstan [27], Republic of Kirghizia [105], Republic of Turkmenistan, Republic of Tajikistan, Afghanistan [106].

Findings in Russia. Samara Region [102] (this article). Doubtful record: Saratov Region [89].

Hosts. Myotis blythii (M. myotis—[27,105]), Eptesicus serotinus [19], E. s. turcomanus [107], Pipistrellus spp., Nyctalus spp. [108], N. noctula (this article, first record), N. lasiopterus (this article, first record).

Doubtful records. Ischnopsyllus (I.) plumatus was recorded in Russia (Saratov Region) for the first time [89]. However, the authors did not notice the hosts’ species and trapping locations, and reported about nine species of bat fleas and two species of gamasid mites untypical for this area. Therefore, in our opinion, further research of the material described in article [89] is needed. The first description of species I. plumatus mentioned the host species as the greater mouse-eared bat Myotis myotis (Borkhausen) obtained from Kazakhstan. According to current studies [109], the bat species has a West-Palearctic distribution, and only this cryptic species, M. blythi Tomes, may be found in Central Asia. Therefore, host specificity of I. plumatus should be corrected.

Note. Ischnopsyllus (I.) plumatus is most likely a polyxenous species, and probably represents the Central Asian form of I. intermedius [105]. The principal host of this species is Eptesicus s. turcomanus (Eversmann), which is distributed in between the Aral and Caspian Seas. The range of this subspecies is parapatric with E. s. serotinus in the Lower Volga region [110,111], possibly facilitating the introduction of I. plumatus into the territory of the Lower and Middle Volga regions.

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Ischnopsyllus (I.) needhami Hsü Yinch’i, 1935 (Figure 6)

(=Ischnopsyllus vassilii Skalon, 1935;

=Ischnopsyllus wassilii Scalon, 1935).

Type material. Holotype l. needhami—♂, paratype—6♂♂, 9 ♀♀ all from Suzhou, China, 8 VI 1934, 26 IX 1934, bat, location unknown. One paratype (♀) is in the Brit. Mus. (Nat. His.). Syntypes I. wassilii—4 ♂♂ and 14 ♀♀ from Kailastuy (Borzinsky District, Chita Region), collected from ‘Chiroptera’, 17 VI 1934 (V.N. Skalon). One ♂ and one ♀ are deposited in the ZIN RAS.

Range: East Palearctic subboreal species, occurring in the steppe zone of Transbaikalia, Primorye Territory, China, Taiwan, Mongolia, and Japan [6,10,11,13,15,28,54,80,86,112,113].

Findings in Russia. Trans-Baikal Territory [15], Primorye Territory [28].

Hosts. Vespertilio sinensis [112]; as Vespertilio superans—[15,19,28], Vespertilio murinus, M. sibiricus (as M. brandtii—[28]), M. bombinus (as M. nattereri—[19]); M. ikonnikovi [28], Murina hilgendorfi (as Murina leucogaster—[28]).

$$

Ischnopsyllus (I.) obscurus (Wagner, 1898)

(=Ceratopsylla obscura (Wagner, 1898);

=Hirtopsylla brachystylus Rothschild, 1910;

=Ischnopsyllus brachystylus Rothschild, 1910).

Type material. Lectotype: ♀ in the Brit. Mus. (Nat. His.); paralectotype: ♀ in the Hamb. Zool. Mus. Both type specimens were collected from Voronezh Region, Bobrovsky District, Khrenovoe Village, on 7 VI 1896, from Vespertilio murinus (leg. A. Silantyev).

New data include 2 ♂♂ ex V. murinus (02 VII 2014) from Vologda Region, Darwin Nature Reserve, leg. A.L. Viskontene, O.A. Shapkin; 7 ♀♀, ♂ ex Pip. kuhlii from Astrakhan Region, Astrakhan Biosphere Reserve, 23 V 2018, leg. D.G. Smirnov; ♀ ex N. noctula, ♀ ex V. murinus from Kaluga Region, Dzerzhinsky, Shenyano-Sloboda Village, pond near the highway, 6 VII 2024, leg. V.A. Korzikov, F. Bobachev; 2 ♂♂ ex V. murinus from Kaluga Region, Dzerzhinsky District, Shenyano-Sloboda Vilage, near houses, 9 VII 2024, leg. V.A. Korzikov, F. Bobachev; ♂ ex N. noctula from Republic of Daghestan, Samur River, 16 VII 2022, leg. D.G. Smirnov; 6 ♀♀, 3 ♂♂ ex V. murinus from Tyumen City, in the period from 9 VI to 25 IX 2022, leg. O.L. Orlov, M.V. Orlova; ♀ ex M. brandtii from Tyumen City, 8 VIII 2023, leg. O.L. Orlov, M.V. Orlova; ♂ ex Nyctalus lasiopterus from Aleshunino Village, 3 VIII 2022, leg. A.V. Pavlov, Y.A. Bykov.

Range: A Palearctic species, known from Scandinavia (Norway, Sweden, Denmark, Finland) to the Far East; it inhabits latitudes between 45° and 60° N [16,22,25,27,54,55,60,61,81,84,85,114,115,116].

Findings in Russia. Leningrad Region [58,60], Vologda Region [88]; (Shapkin et Babushkin, in press; this article), Yaroslavl Region [88], Kostroma Region [88], Tver’ Region [60], Kursk Region [88], Voronezh Region [54], Saratov Region [7,63,89,101], Samara Region, Volgograd Region (as Tsaritsin—[54]), Sverdlovsk Region, Chelyzbinsk Region, Tyumen Region, Tomsk Region, Republic of Buryatia, Trans-Baikal Territory, Amur Region, Primorye Territory [28], (Eastern part of Russian Plain—[69]), (Volga-Kama region without specification [70]).

Hosts. Vespertilio murinus (as Vesperugo discolor—[7,19,24,54] (Shapkin et Babushkin, in press; this article), V. sinensis (as V. superans—[28]), N. noctula (Shapkin et Babushkin, in press), N. lasiopterus (this article, new record), P. pygmaeus, P. nathusii [24], M. dasycneme, M. daubentonii (as Vespertilio daubentonii—[54]), E. nilssonii [19,24,112], E. serotinus [19].

Note. According to S.G. Medvedev [22], the principal host of I. obscurus is the parti-colored bat (Vespertilio murinus), a Palearctic species that accounts for the wide distribution of this flea. Some European sources also identify V. murinus as the main host of I. obscurus [104].

Ischnopsyllus (I.) octactenus (Kolenati, 1856) (Figure 7)

(=Ceratophylla jubata Wagner 1894;

=Ceratophyllus octactenus Kolenati, 1856;

=Ceratophyllus variabilis subsp. decimpilata;

=Ceratopsylla jubata Wagner 1894;

=Ceratopsyllus jubata Wagner 1894;

=Ceratopsyllus octactenus Kolenati, 1856).

Type material. The location of the types of the senior synonym is not established—decimpilata (Ceratopsylla variabilis var.): holotype, ♂, Kara-Dag, Crimean Peninsula, bat, 1894; paratype—same data; deposited in the Hamburg Zoological Museum—jubata (Ceratopsylla): holotype, ♂, Kara-Dag, Crimean Peninsula, bat, 1894 (Julius Wagner); deposited in the Hamb. Zool. Mus.

New data: ♀ ex P. pygmaeus from Kozelsky District, Dmitrovsky, 10 VII 2020, leg. A.V. Rogulenko, E.F. Sitnikova; ♂, 2 ♀♀ ex P. pygmaeus from Kozelsky District, Chernysheno Village, 11 VII 2020, leg. V.A. Korzikov, Rogulenko A.V.; ♂ ex P. pygmaeus from Kozelsky District; ♀ ex Nyctalus noctula from Kozelsky District, Chernysheno Village, 14 VII 2021, leg. V.A. Korzikov, A.V. Rogulenko; 2 ♂♂ 4 ♀♀ ex Pip. pygmaeus from Kozelsky District, Chernysheno Village, 4 VII 2022, leg. V.A. Korzikov, Karpushin S.E.; ♂, ♀ ex Pip. pygmaeus from Kozelsky District, Chernysheno Village, 5 VII 2023, leg. V.A. Korzikov, F. Bobachev; 2 ♀♀ ex M. mystacinus from Kozelsky District, Berezichsky Glass Factory, 23 VIII 2023, leg. V.A. Korzikov, F. Bobachev; 7 ♂♂, 15 ♀♀ ex Pip. pygmaeus, ♂, 3 ♀♀ ex P. natusii from Kozelsky District, Optina Pustyn’ Village, 5,7 VII 2022, leg. V.A. Korzikov, S.E. Karpushin; ♂ ex Pip. pygmaeus from Kozelsky District, Optina Pustyn’ Village, 19 VII 2024, leg. V.A. Korzikov, F. Bobachev; ♂, 9 ♀♀ ex Pip. pygmaeus from Kozelsky District, Poloshkovo Village, 7 VII 2022, leg. V.A. Korzikov, Karpushin S.E.; ♀ ex Pip. pygmaeus from Peremyshlsky District, Ilyinskoye Village, 11 VII 2023, leg. V.A. Korzikov, F. Bobachev; ♂ ex M. daubentonii from Peremyshlsky District, Kaluga experimental agricultural station, 6 VII 2023, leg. V.A. Korzikov, F. Bobachev; ♀ ex Pip. nathusii from Dzerzhinsky District, Luzhnoe Village, 8 VII 2024, leg. V.A. Korzikov, F. Bobachev; ♂ ex P. nathusii, ♂ ex V. murinus from Dzerzhinsky District, Shenyano-Sloboda Village, 9 VII 2024, leg. V.A. Korzikov, F. Bobachev; ♀ ex Pip. nathusii Astrakhan Biosphere Reserve, 28 VIII 2019, leg. D.G. Smirnov; 6 ♀♀, ♂ ex Pip. nathusii from (6–16 VI 2018), 8 ♀♀, 2 ♂♂ ex Pip. nathusii (13–21 VII 2019), 2 ♀♀ ex V. murinus (13 VII 2018), ♀ ex E. nilssonii (20 VII 2019), ♀ ex E. serotinus, ♀ ex M. dasycneme (27 XI 2018), ♀ ex N. lasiopterus (23 VII 2018), ♀ ex N. lasiopterus (21 VII 2019), ♀ ex N. noctula (8 VII 2018) from Samarskaya Luka National Park, leg. D.G. Smirnov.

Range: Western Palearctic species; the range covers Europe, from Great Britain and Scandinavia to the Mediterranean [60,82,83,85,107], Turkey [78], Lebanon [117], Central Asia [27]; also discovered in the Canary Islands [118], northern Morocco, Tunisia, and Algeria [93,119], Afghanistan [120,121,122], and northern Iran [123].

Findings in Russia. Vologda Region (Shapkin et Babushkin, in press), Republic of Crimea [100,124,125,126], Kaluga Region (this article, new record), Smolensk Region [88], Bryansk Region [88], Republic of Mordovia [65], Saratov Region [89], Rostov Region [65,127], Krasnodar Territory [16,128], Republic of North Ossetia—Alania [16], Republic of Daghestan [127].

Hosts. Pipistrellus spp.: P. pipistrellus s.l. (as Vespertilio pipistrellus, as Scotophilus pipistrellus—[19,27,54,81] (this article), P. nathusii (Shapkin et Babushkin, in press) [19] (this article), P. kuhlii [19], as Vespertilio kuhlii—[54], P. pygmaeus [65] (this article), Myotis mystacinus [19], this article, as Vespertilio mystacinus—[54], M. nattereri [19], as Vespertilio nattereri—[54], M. daubentonii [19,103], (this article), M. dasycneme (Shapkin et Babushkin, in press, this article), M. emarginatus [103], M. myotis [103,129,130], Nyctalus noctula [19,65], (as Vesperugo noctula—[54]), Nyctalus leisleri (as Vesperugo leisleri, as Scotophilus leisleri, as Pterygistes leisleri—[54]), N. lasiopterus [102], E. serotinus [19,103] (this article), E. nilssonii [19,103] (this article), Plecotus auritus [19,81,103], Barbastella barbastellus [19,103], Vespertilio murinus [103] (this article), Hypsugo savii (as Vespertilio savii, as Pipistrellus savii—[54], Rhinolophus hipposideros [103], Miniopterus schreibersii [129], (Mus musculus [54]), (Delichon urbuca [55]). Doubtful records: P. pipistrellus s.l. (Republic of North Ossetia—Alania—[16]), P. abramus (Pakistan—[19,131]).

In 20th-century sources, authors did not distinguish between Pipistrellus pipistrellus and Pipistrellus pygmaeus, so it is unclear which species was being referred to.

The record of Pipistrellus attributed to P. abramus (Temminck) in Pakistan is most likely Pipistrellus cf. javanicus, as P. abramus does not inhabit South Asia.

Ischnopsyllus (I.) simplex Rothschild, 1906

Type material. Lectotype: ♂, Wels, Austria, Myotis mystacinus, 1910 (D. Rothschild). Paralectotypes include 4 ♂♂, 19 ♀♀—same data. Additional specimen: ♂, Prestebakke, Oslo region, Norway, M. mystacinus, 21 VIII 1907.

Material. ♀ ex Pip. pipistrellus from Sovetskoe Settlement, 27 IV 2022, leg. D.G. Smirnov.

Range: Western Palearctic: Britain, France, Belgium, Netherland, Germany, Czech Republic, Belarus [23,54,60,83,85,117,132]. Two subspecies have been identified that differ in males; their ranges overlap, and some authors consider them separate species [23,83,132]. Another subspecies (Ischnopsyllus (I.) simplex mysticus (Jordan, 1942)) has been recorded in Finland, Estonia, and Latvia [24,60].

Finding in Russia. Republic of Karelia [133], Saratov Region [89], Republic of Daghestan (this article).

Hosts. Myotis spp.: Myotis brandtii [19,133], M. nattereri [19,24], M. mystacinus [19,24], M. dasycneme [24], M. bechsteinii [19]; Pl. auritus [19]; V. murinus [19], Barbastella barbastellus [19,24], E. serotinus [19], E. nilssonii [19], Rhinolophus hipposideros, P. pipistrellus s.l. [19].

Note. J. Burazerovits and co-authors [134] indicate that the main host is Natterer’s bat, M. nattereri (Kuhl).

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Ischnopsyllus (I.) variabilis (Wagner, 1898) (Figure 8)

(=Ceratopsylla variabilis Wagner, 1898;

=Ceratopsyllus variabilis subsp. decimpilata Wagner, 1898).

Type material. Lectotype: ♂, Voronezh Region, Khrenovoe Village, Pip. nathusii, 18 VI 1896 (A. Silantyev), location unknown. Paralectotypes: ♂—the same place and collector, but 7 VI 1896; ♀—Saratov Region, no date, collector not specified (K. Kessler), both pairs of the lectotypes are stored in Hamb. Zool. Mus. ♀—data as for the lectotype, stored in the Brit. Mus. (Nat. Hist.). ♂—Minino, Staritsky District, Kalinin Region, bat, 1893 (V. Bianki), stored in the ZIN RAS.

New data include 13 ♀♀, 2 ♂♂ ex Pip. nathusii from Dzerzhinsky District, Rudnya Village, 10 VII 2023, leg. V.A. Korzikov, F. Bobachev; 13 ♀♀ 4 ♂♂ ex Pip. nathusii, 2 ♀♀ ex Pip. pygmaeus from Dzerzhinsky District, Luzhnoe Village, 8 VII 2024, leg. V.A. Korzikov, F. Bobachev; 46 ♀♀ 10 ♂♂ ex Pip. nathusii, 4 ♀♀, 4 ♂♂ ex V. murinus from Dzerzhinsky District, Shenyano-Sloboda, 6,9 VII 2024, leg. V.A. Korzikov, F. Bobachev; ♀ ex M. daubentonii, 21 ♀♀ 5 ♂♂ ex Pip. nathusii, 2♀♀ ♂ ex Pip. pygmaeus from Kozelsky District, Optina Pustyn’ Village, 5, 10 VII 2022, leg. V.A. Korzikov, A.V. Rogulenko; 2 ♀♀ ex Pip. nathusii, ♀ ex Pip. pygmaeus from Kozelsky District, Optina Pustyn’ Village, 19 VII 2024, leg. V.A. Korzikov, Bobachev F.; ♀ ex M. mystacinus, ♀ ex Nyctalus noctula, ♂ ex Pip. nathusii from Kozelsky District, Berezichsky Glass Factory, 8, 23 VIII 2023, leg. V.A. Korzikov, F. Bobachev; ♂ ex M. daubentonii from Kozelsky District, Nizhnie Pryski Village, 8 VII 2022, leg. V.A. Korzikov, S.E. Karpushin; ♂ 2 ♀♀ ex Pip. nathusii from Kozelsky District, Poloshkovo Village, 7 VII 2022, leg. V.A. Korzikov, Karpushin S.E.; ♀ ex Pip. pygmaeus from Peremyshlsky District, Ilyinskoye Village, 11 VII 2023, leg. V.A. Korzikov, F. Bobachev; ♀ ex M. daubentonii from Peremyshlsky District, Vorotynsk Village, 11 VII 2023, leg. V.A. Korzikov, F. Bobachev; ♂ 2 ♀♀ ex P. nathusii, 6 VIII 2021, from Yukhnovsky District, Tents Village, leg. V.A. Korzikov, Rogulenko A.V.; 3 ♀♀ ex P. nathusii from Kozelsky District, Berezichsky Glass Factory, 13 VII 2020, leg. V.A. Korzikov, F. Bobachev; ♂ ex P. pygmaeus from Kozelsky District, Volosovo-Zvyagino Village, 13 VII 2021, leg. V.A. Korzikov, A.V. Rogulenko; ♀ ex M. dasycneme from Aleshunino Village, 31 V 2024, leg. A.V. Pavlov, Y.A. Bykov; 3♀♀, ♂ ex Pip. nathusii from Aleshunino Village, 14 VIII 2024, leg. A.V. Pavlov, Y.A. Bykov; ♀ ex M. daubentonii from Aleshunino Village, 14 VIII 2024, leg. A.V. Pavlov, Y.A. Bykov; ♀ ex M. dasycneme (3 XII 2021), 2 ♀♀ ex N. leisleri (18 VII 2018), 25 ♀♀, 6 ♂♂ ex Pip. nathusii (VII 2018), 2♀♀, 2♂♂ ex V. murinus from Samarskaya Luka National Park, leg. D.G. Smirnov, M.S. Malyavina; 2♀♀ ex Pip. nathusii (29 V 2018), ♀ ex Pip. nathusii (28 VIII 2019) from Astrakhan Biosphere Reserve, leg. D.G. Smirnov; 48 ♀♀, 6 ♂♂ ex Pip. nathusii (VI–VII 2023, VI 2024), ♀, ♂ ex Pip. pygmaeus (9 VII 2022), ♀, ♂ ex Pip. pygmaeus (9 VI 2023), ♀ ex Pip. pygmaeus (27 VI 2024) from Shemysheysky District, Research Station of Penza State University, leg. D.G. Smirnov; 3 ♀♀, 3 ♂♂ ex Pip. nathusii from Ichalkovsky District, Bandasevsky Cordon Tract, Mitryashka Lake, leg. D.G. Smirnov; 17 ♀♀, 5 ♂♂ (VII 2018), 8♀♀, ♂ (VII 2019) ex Pip. nathusii, 2 ♀♀ ex N. leisleri (VII 2018), 2 ♀♀, 2 ♂♂ ex V. murinus (14 VII 2018), ♀ ex M. dasycneme (3 XII 2021) from Samarskaya Luka National Park, leg. D.G. Smirnov, M.S. Malyavina.

Range: Western Palearctic species found in Europe on migratory bat species (Pipistrellus spp., N. noctula) [24,82,83,85,116,135,136,137,138].

Findings in Russia. Leningrad Region [60], Pskov Region [25], Vologda Region (Shapkin et Babushkin, in press), Moscow Region [88], Voronezh Region [88], Kursk Region [88], Vladimir Region (this article, new record), Kaluga Region (this article, new record), Penza Region [22,25,60], Kirov Region [33], Udmurtian Republic [33], Saratov Region [89,101], Stavropol’ Region [16], Karachayevo-Circassian Republic [16], Republic of Daghestan [65], Ulyanovsk Region [127], Republic of Mordovia [65], Kirov Region [33], Republic of Bashkortostan [65], Chelyabinsk Region [65], (Volga-Kama region without specification [70]). The distribution boundaries generally correspond to the range of the principal host, Nathusius’ pipistrelle.

Hosts. Pipistrellus nathusii [19,24,54], Shapkin et Babushkin, in press(this article), P. pipistrellus s.l. [19,54], P. kuhlii [54,127], P. pygmaeus [65] (this article), Nyctalus noctula [19], (as Vesperugo noctula—[54] (this article), Nyctalus leisleri [19,54], Myotis dasycneme [24,65] (this article), M. daubentonii [19,81] (this article), M. mystacinus [19,81], M. brandtii [24], M. nattereri [19]; Vespertilio murinus [24,81] (this article), E. serotinus [19], (as Vespertilio serotinus—[54]), Ep. nilssonii [19,24,81], Plecotus auritus [19,81], Barbastella barbastellus [19,24,81].

$$

Subgenus Hexactenopsylla Oudemans, 1906

Ischnopsyllus (Hexactenopsylla) hexactenus (Kolenati, 1856)

(=Ceratophyllus hexactenus (Kolenati, 1856);

=Ceratopsyllus hexactenus Kolenati, 1856;

=Ischnopsyllus bouchei Oudemans, 1906;

=Ischnopsyllus kolenatii Wagner, 1930;

=Nycteridopsylla bouchei Oudemans, 1906;

=Pulex vespertilionis Bouché, 1835).

Type material. I. hexactenus has not been preserved. The types of I. kolenati from Minusinsk (Krasnoyarsk Territory, Russia) collected from Plecotus auritus, and from the Saratov Region collected from Vespertilio murinus, are stored in the Hamb. Zool. Mus [19].

Material. ♂ ex P. auritus, from Tanechkina Cave, 14 X 2022, leg. A.L. Viskontene.

Range: Palearctic species, widespread in Europe [81,85,116,135,136].

Findings in Russia. Leningrad Region [10,59,61], Moscow Region [59,89], Saratov Region [4,58,89], Samara Region [95], Republic of North Ossetia—Alania [16], Sverdlovsk Region [33], Bashkiria Republic [65], Republic of Khakassia [65], Krasnoyarsk Region [58], Irkutsk Region [58,65], Republic of Buryatia [65], Trans-Baikal Territory [65], Primorye Territory [52], (Urals, Trans-Urals, Trans-Caucasus [29,52]), (Volga-Kama region without specification [70]).

Hosts. Plecotus auritus [19,24,54,71,139], Pl. austriacus, Pl. ognevi [65], as Plecotus auritus—[28], Myotis mystacinus [19,71], as Vespertilio mystacinus—[54], M. nattereri [24], as Vespertilio nattereri—[54], M. sibiricus (as Myotis brandtii—[28]), M. brandtii [24,71], M. myotis [19,139], M. daubentonii [19,24,71], M. dasycneme [19,24,71], M. petax (as Myotis daubentonii—[28]), M. ikonnikovi [28], Nyctalus noctula [136], Barbastella barbastellus [19,24,139], as Synotus barbastellus—[54], Vespertilio murinus [4,19,24] E. serotinus [19], as Vespertilio serotinus—[54], E. nilssonii [19,24]; Hypsugo alashanicus (as Pipistrellus savii—[28]), Pipistrellus nathusii [71], Murina hilgendorfi [65], Miniopterus fuliginosus (as Min. schreibersii—[28]), Rh. ferrumequinum [19], (Homo sapiens [54]).

Note. In Russia, records in Siberia and the Far East [24], previously attributed to the brown long-eared bat (Plecotus auritus), should obviously be attributed to Ognev’s long-eared bat (Pl. ognevi).

Ischnopsyllus (H.) petropolitanus

$$

(=Ceratopsyllus petropolitanus;

=Ceratopsyllus hexactena subsp. petropolitana).

Type material. Holotype, ♂, Saint Petersburg (as Leningrad), bat (without specification), 1898 (Julius Wagner), stored in Hamb. Zool. Mus.

Range and findings in Russia: West–Central Palearctic species: distributed from the Baltic (Saint Petersburg) to the Ciscaucasia, northern Kazakhstan (Lake Zaysan) [57,85,106] and Mongolia [112] extending to foothill and mountainous regions (up to 2000–3000 m above sea level) of Turkmenistan, Tajikistan, Kazakhstan, Mongolia, and Uzbekistan [27]; also collected in Iran [45].

Hosts. Plecotus spp. [20], Plecotus strelkovi as Plecotus austriacus—[27], alpine long-eared bat Plecotus macrobullaris Kuzjakin, 1965 [45]; Eptesicus spp. [106]; Myotis spp. [112].

Note. Medvedev [19] suggested that the occurrence of the type specimen in Saint Petersburg may have been accidental, possibly resulting from bat migration.

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Ischnopsyllus (H.) ussuriensis Medvedev, 1986

Type material. Paratypes: Kamchatka Region, Ust-Kamchatsk, Myotis brandtii, 28 VI 1983—♀ (M. Tiunov); Primorye Territory, Anuchinsk District, 30 km from Arsenyev Town, M. brandtii, 9 III 1981—♀ (M. Tiunov); Primorye Territory, Suputinsky Reserve (now Ussuriyskiy Nature Reserve, Russia), bat, 9 VIII 1954—2 ♂♂, 5 ♀♀ (I. Amosova). Specimens are deposited in ZIN RAS [19].

Range and findings in Russia: The species is known from isolated records in the Russian Far East [20,28].

Hosts. M. sibiricus [28]—(as M. brandtii and M. ikonnikovi [28]).

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Ischnopsyllus (H.) comans Jordan, Rothschild, 1921 (Figure 9)

Type material. Holotype—♂; paratype—♀, China, Paiping, Nyctalus noctula (M. Plansu). Stored in the Brit. Mus. (Nat. Hist.).

Range: Russia [10,28], China [10], Republic of Korea [54], Mongolia [139].

Findings in Russia. Far East (Khabarovsk Territory, Primorye Territory, Kamchatka Territory) [10,28,115].

Hosts. Hypsugo alashanicus (as Vespertilio savii—[10]; as Pipistrellus savii—[28], Nyctalus labiata (as Pipistrellus planeyi—[114]), Myotis fimbriatus Peters (as Leuconoe taiwanensis—[114]); as M. adversus—[19]), M. sibiricus [28], as Myotis mystacinus—[19,112,139], M. petax [28], as M. daubentonii—[19], M. ikonnikovi [28].

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Genus Nycteridopsylla Oudemans, 1906

Nycteridopsylla pentactena (Kolenati, 1856) (Figure 10)

(=Ceratophyllus pentactenus Kolenati, 1856;

=Ceratopsyllus pentactena Kolenati, 1856;

=Ceratopsyllus tetractenus Kolenati, 1856;

=Typhlopsylla pentactenus Taschenberg, 1880).

Type material. Unknown.

Material. ♀, 5 ♂♂ ex B. barbastellus from Fort № 1 ‘Steinz’, 3♂♂ from Fort № 2 ‘Bronzart’, ♂ from Fort № 3 ‘Friedrich III’, 2♀♀ from Fort № 5 ‘Friedrich Wilhelm III’ (07–10 II 2024), ♀, ♂ ex E. nilssonii from Fort № 5 ‘Friedrich Wilhelm III’ (09 II 2024), ♀ ex M. nattereri from Fort № 1 ‘Steinz’ (08 II 2024), leg. A.L. Viskontene, E.A. Khizhkin; ♀ ex P. auritus (13 II 2022) from Fort № 2 ‘Bronzart’, leg. M.Yu. Markovets.

Range: Europe (except northern regions) from Germany to the Mediterranean [85,140,141,142,143], Ukraine [16], Russia [16], Azerbaijan [141]; North Africa [93,129].

Findings in Russia. Kaliningrad Region [16] (this article).

Hosts. Barbastella barbastellus [19] (this article), Plecotus auritus [19,142] (this article), Pl. austriacus [139], P. pipistrellus [19,139]. P. kuhlii [141], Eptesicus serotinus [140]; E. nilssonii [144] (this article), E. isabellinus [93], H. savii (as P. savii—[19]), N. noctula [19], M. dasycneme [19], M. myotis [19], M. mystacinus [19], M. nattereri [19,139] (this article), E. serotinus [19], Rhinolophus ferrumequinum [19], Rh. hipposideros [19].

Note: Beaucournu and Quetglas [93] consider Eptesicus serotinus to be the primary host of this species.

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Nycteridopsylla longiceps Rothschild 1908

(=Ceratopsylla pentactenus Kolenati 1856).

Type material. Holotype: ♂ from Welwyn, Herts. (England) ex Scotophilus pipistrellus, 10 IV 1898, W. R. O. Grant. Paratypes: ♂ from Tring (England) ex Scotophilus pipistrellus, 14 IV 1898, N.C.R.; ♀ from Tring (England) ex Plecotus auritus, I 1898, K. Jordan; 2 ♀♀ from Tring, ex Plecotus auritus, 01 I 1898 and 01 VI 1898, N.C.R.; ♂ in alcohol Tring, Herts. (England) ex Myotis nattereri, 22 IV 1953. F.G.A.M. Smit (Brit. Mus. 1953.850); 2 ♀♀ Henley-on-Thames (England) ex Plecotus auritus, XII 1907, A.H. Bishop.

Range: A Western Palearctic species, its distribution extends from Europe (including southern Great Britain and Ireland) to the Mediterranean region (including Turkey) [54,81,82,83,85,121].

Findings in Russia. Kaliningrad Region [144].

Hosts. Plecotus auritus [54], Pipistrellus pipistrellus s.l. [19], Plecotus auritus [19,145], P. kuhlii [19], H. savii (as P. savii—[19]), Myotis nattereri, M. myotis [19], M. mystacinus [19], Nyctalus noctula [19], Nyctalus leisleri [19], E. serotinus [19]; Barbastella barbastellus [19,139].

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Nycteridopsylla eusarca Dampf 1908 (Figure 11)

(=Nycteridopsylla eusarca subsp. major Rothschild, 1909;

=Nycteridopsylla pungens Hopkins, 1949).

Type material. Lectotype, ♂; paratype ♀ Strugga, Poland (West Prussia), ex Delichon (Chelidon) urbica, P. Speiser. Deposited in Germany. Holotype ♂, paratype ♂ of eusarca major, Cambridge ex Nyctalus noctula (as Vesperugo noctula), I 1892 D. Sharp. deposited in the Brit. Mus. (Nat. Hist.)

Range: Found across Western and Eastern Europe, extending to Ciscaucasia [106].

Findings in Russia. Stavropol’ Territory [16,77,106], Rostov Region [91].

Hosts. Nyctalus noctula, M. myotis, M. daubentonii [19], M. blythii, Pipistrellus pipistrellus s.l. [19], P. kuhli, Vespertilio murinus, Plecotus auritus [19], Pl. austriacus [19], Barbastella barbastellus [19], Delichon urbica (Linnaeus, 1758) [54,129,136,139,146,147,148,149].

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Genus Rhinolophopsylla Oudemans, 1909

Rhinolophopsylla unipectinata unipectinata (Taschenberg, 1880) (Figure 12)

(=Araeopsylla hispanica Gil Collado, 1934;

=Ceratopsylla unipectinata Koaut, 1903;

=Typhlopsylla unipectinata Baker, 1895).

Type material. Holotype: ♂, Tashkent Area (Kara-Kamysh), Rhinolophus hipposideros, 20 X 1950 (O. Bogdanov), stored in the Scientific Research Institute of the Caucasus and Transcaucasia.

Material includes 6 ♀♀, 4 ♂♂ ex Rhinolophus ferrumequinum from Akushin District, Verkhnie Mulyobki Settlement, 2023 (without specification), leg. A.V. Zhigalin.

Range: Subboreal zone of Europe, Central Asia, the Mediterranean, and Northern Africa [54].

Findings in Russia. Previously recorded in Crimea, the Rostov Region, and the Caucasus [10,16,19,55,61,125,126].

Hosts: Rhinolophus spp., Rh. ferrumequinum [19,93], Rh. hipposideros [19], Rh. bocharicus [19], Rh. euryale [19], M. blythii [19], M. myotis [19], M. capaccinii [19], M. emarginatus [19], P. nathusii [19], P. pipistrellus [19], P. pygmaeus, N. noctula, Miniopterus schreibersi [16,19].

4. Discussion

Eighteen bat flea species belonging to four genera are currently described from the territory of the Russian Federation: one species of Myodopsylla, thirteen species of Ischnopsyllus, three species of Nycteridopsylla, and one species of Rhinolophopsylla.

New host–parasite relationships are Pip. pygmaeus–Myodopsylla trisellis and Ischnopsyllus (I.) intermedius, Myotis dasycneme–Ischnopsyllus (I.) elongatus, N. lasiopterus–Ischnopsyllus (I.) obscurus, N. lasiopterus–Ischnopsyllus (I.) plumatus, N. noctula–Ischnopsyllus (I.) plumatus, N. lasiopterus–Ischnopsyllus (I.) intermedius, N. leisleri–Ischnopsyllus (I.) elongatus, and Plecotus auritus–Ischnopsyllus (I.) elongatus. Ischnopsyllus (I.) elongatus is reported for the first time from the Kaluga, Vladimir, and Samara regions, and Ischnopsyllus (I.) intermedius is newly recorded for the Samara Region. Ischnopsyllus (I.) octactenus is a new ectoparasite record for Kaluga and Vladimir regions, while Ischnopsyllus (I.) variabilis is newly documented in the Kaluga Region.

Host specificity varies considerably among different bat flea species (Figure 2). Siphonaptera are generally believed to be rarely monoxenous at the host species level, instead infesting groups of related species [150]. This pattern is supported by our findings for the genera Myodopsylla (fleas of Myotis bats), Rhinolophopsylla (parasites of Rhinolophus bats), and several Ischnopsyllus species in Russia (Figure 2). C. Dick [151] has argued that obligate parasitism promotes higher host specificity across ectoparasitic groups. This is partly true for bat fleas, which are indeed obligate blood-sucking insects. More than half of the species observed in our study are oligoxenous. Nevertheless, I. variabilis, I. plumatus, I. intermedius, N. pentactena, and N. longiceps appeared to be polyxenous. However, seasonal changes in host specificity have been documented for bat flies [152]. In light of this, a more detailed investigation into seasonal host specificity among bat fleas is warranted. Furthermore, the migratory behavior of host species, the numbers and types of roosts, roost fidelity, and the tendency to form large colonies may all influence the parasitic fauna of individual hosts [151].

Among the 52 bat species inhabiting Russia, fleas have been recorded on 36 species (69%). The remaining 31% of the chiropteran fauna consists of rare and vulnerable species, and the lack of flea records for these may be attributed to the difficulty of capturing these host species. These species include Tadarida teniotis, T. insignis, Miniopterus schreibersii, Rhinolophus mehelyi, Barbastella pacifica, Murina ussuriensis, Plecotus macrobullaris, P. sacrimontis, Myotis alcathoe, M. macrodactylus, M. tschuliensis, M. bombinus, M. bechsteini, Eptesicus pachyomus, and E. gobiensis.

An analysis of bat flea distributions suggests that their fauna has a distinctly Western Palearctic character: Ischnopsyllus dolosus, I. intermedius, I. octactenus, I. simplex, I. variabilis, I. petropolitanus, all species of the genus Nycteridopsylla, and Rhinolophopsylla have a Western Palearctic distribution. Only three species (Myodopsylla trisellis, I. needhami, and I. comans) inhabit the Eastern Palearctic territories of Russia, while I. elongatus, I. obscurus, and I. hexactenus are distributed throughout the entire Palearctic.