Laelaps pavlovskyi Zakhvatkin, 1948

Vinarski, Maxim V. & Korallo-Vinarskaya, Natalia P., 2016, An annotated catalogue of the gamasid mites associated with small mammals in Asiatic Russia. The family Laelapidae s. str. (Acari: Mesostigmata: Gamasina), Zootaxa 4111 (3), pp. 223-245 : 231

13. Laelaps pavlovskyi Zakhvatkin, 1948

Laelaps pavlovskyi Zakhvatkin, 1948: 66 , figs 4, 7.

Laelaps pavlovskyi . — Lange, 1948: 83; Bregetova & Kolpakova, 1952: 60; Bregetova, 1953: 311; Lange, 1955: 333, fig. 684; Bregetova, 1956: 110, 116, fig. 208; Bregetova & Kolpakova, 1956: 187; Goncharova, 1956: 202; Vysotskaya & Bregetova, 1957: 14; Lange, 1958: 205, pl. LXXIII, P; Strandtmann & Wharton, 1958: 68; Tipton, 1960: 280, pl. 22, figs 24k, 27e, 29c, 33c, 34b; Goncharova & Buyakova, 1964: 283, fig. 3, 1; Zemskaya, 1973: 146; Nikulina, 1987: 231, fig. 117: 8.

Laelaps agrarius . — Strandtmann & Wharton, 1958: 59.

Laelaps pavlovskyi agrarius Lange, 1948: 83 , figs 1 C, 2 D.

Laelaps jettmari . — Senotrusova, 1987: 165, fig. 81 (partim); Goncharova et al., 1991: 32 (partim); Mašán & Fenďa, 2010: 36 (partim).

Type locality. Russia, Astrakhan’ Region, the Volga River delta, Astrakhan’ Nature Reserve (Obzhorovsky District).

Type host. Apodemus agrarius .

Principal hosts. Mice of the genus Apodemus (according to Zemskaya, 1973).

Distribution. Northern Palaearctic, from Western Europe to the Far East, including Japan and the Korean Peninsula ( Tipton, 1960; Zemskaya, 1973). In Asiatic Russia, L. pavlovskyi is widely distributed in Siberia and in the southern part of the Russian Far East ( Nikulina, 2004).

Remarks. The taxonomic validity of L. pavlovskyi is disputable. Some acarologists believe it to be a good species (Bregetova, 1956; Tipton, 1960; Salmane 2001), whereas other authors follow Mrciak (1964), who synonymised L. pavlovskyi with L. jettmari ( Senotrusova, 1987; Goncharova et al., 1991; Mašán & Fenďa, 2010). Mrciak (1964) also found no significant morphological differences between the two species. However, in parasitic gamasid mites, ecologically distinct species parasitising phylogenetically and ecologically distinct hosts are sometimes very similar in morphology. Ecologically segregated cryptic species are not rare within Mesostigmata ( Muma & Denmark, 1969; Zuevsky, 1970; Engelbrecht et al., 2014; Skoracka et al., 2015). Concerning the species pair L. jettmari—L. pavlovskyi, Tipton (1960: 281) stressed that “host relationships are of some significance in distinguishing these species”. Indeed, L. pavlovskyi is primarily associated with Apodemus mice, whereas L. jettmari infests hamsters of the genus Cricetulus . These two rodent genera are not phylogenetically related and belong to different families, Muridae Gray, 1821 and Cricetidae Fischer, 1817 , respectively. Their ecology is also different, which implies strong habitat segregation between hosts and, hence, spatial and ecological isolation between mites. Furthermore, it is uncommon for a particular Laelaps species to be associated with phylogenetically distant mammals (see Discussion). All species of Laelaps living in Northern Asia are associated with hosts belonging to the same genus ( L. algericus , L. hilaris , L. nuttalli and others) or, rarely, with hosts of taxonomically close genera ( L. clethrionomydis ). Some generalist species of this genus proved to represent complexes of cryptic species confined to different host taxa ( Engelbrecht et al., 2014). In our opinion, morphological similarity between mites associated with phylogenetically distant taxa of mammals is not a sufficient argument to conclude their conspecificity, and the synonymy between L. pavlovskyi and L. jettmari should be corroborated by means of more sophisticated research techniques that are currently used in the studies of the cryptic speciation in the Acari (Skoracka et al., 2015, Lareschi & Galliari, 2014).