Structure of ectoparasite communities of Nyctalus species (Chiroptera: Vespertilionidae) in the Zhiguli State Nature Reserve and Samarskaya Luka National Park (European Russia)

Abstract

The ectoparasites of the bats (Chiroptera) often act as carriers of infectious agents dangerous to animals and humans. This determines the relevance of studying ectoparasite communities. In this regard, the composition of communities and interspecific relations of ectoparasites of migratory bats are of particular interest, since they can be a source of arthropods with vector potential that are atypical in a studied area. This research was aimed to study the species composition, community structure and parasite-host specificity of ectoparasites in syntopic populations of bats of the genus Nyctalus. The study has been carried out in the Zhiguli State Biosphere Reserve and Samarskaya Luka National Park (Russia). A total of 78 individuals of Nyctalus were examined, namely Nyctalus noctula (47 individuals), N. leisleri (21 individuals) and N. lasiopterus (ten individuals). They were captured by ornithological nets in the summer period in 2017–2019. The collected ectoparasites were fixed in alcohol, and permanent preparations were made using Fora-Berlese liquid. In total, we found 19 ectoparasite species, namely one Hemiptera species (Cimex lectularius), four Ischnopsyllidae species, and 14 species of Spinturnicidae and Macronyssidae families. Of these, eight ectoparasite species have been found for the first time in Russia on Nyctalus species. Nine ectoparasites species were found on Nyctalus leisleri, 15 species on N. noctula, and 11 species on N. lasiopterus. The most massive and widespread parasite on Nyctalus is Macronyssus flavus. In addition, we demonstrated a high infestation of Nyctalus noctula by Spinturnix acuminatus and Steatonyssus noctulus, of Nyctalus lasiopterus by Spinturnix acuminatus and of Nyctalus leisleri by Steatonyssus spinosus. Among casual parasites of Nyctalus, there are Spinturnix helvetiae, S. myoti, S. plecotinus, Ischnopsyllus octactenus, I. variabilis, Macronyssus ellipticus, and Steatonyssus periblepharus. The correspondence analysis of certain ectoparasite communities, differing in qualitative and quantitative composition, with the host species demonstrated the general structure of parasite-host relationships. Nyctalus noctula has the highest diversity of ectoparasite communities and the model of the log-normal distribution of species abundance confirmed this. In terms of species composition, the parasite communities of Nyctalus noctula and N. lasiopterus were the most similar, while the parasite communities of Nyctalus noctula and N. leisleri were the least similar. The key components involved in the differentiation of ectoparasitic communities were the following species: Spinturnix acuminatus, S. kolenatii, Steatonyssus spinosus, and Macronyssus flavus, which have different infestation values in their hosts. Co-occurrence analysis revealed a strong positive relationship for 28 ectoparasite species pairs and a strong negative relationship for 26 species, which may be explained by weakened competitive relations between the ectoparasites. The observed assortativity of parasite species among themselves has been discussed.