Ticks (Acari: Ixodidae) and laelapid mites (Acari: Mesostigmata: Laelapidae) on small rodents in Lithuania

Abstract

From the human health perspective, rodent-ectoparasite associations are hugely important in most ecosystems. Climatic changes have caused the spread of ectoparasites into new regions and increased their abundance. They also have had indirect effects on host ecology and abundance, causing the emergence of vector-borne diseases. Rodents are important hosts of the immature stages of the tick Ixodes ricinus which has expanded its range in recent decades, and its population density has increased within known endemic areas in Europe. Laelapidae mites are ecologically diverse and are frequently associated with small rodents. These mites are a medically important group worldwide. However, there is a lack of knowledge on the distribution and host associations of ticks and mites in Baltic countries. The aim of this study was to investigate ticks and mites parasitizing small rodents and estimate their infestation patterns on different rodent species inhabiting the Curonian Spit in western Lithuania. Small mammals were captured in different locations in the Curonian Spit during 2013–2016. A total of 565 small rodents representing 7 species were trapped, namely Apodemus flavicollis, A. agrarius, Myodes glareolus, Micromys minutus, Microtus oeconomus, M. arvalis and M. agrestis. The captured rodents harboured I. ricinus ticks (n = 1,250) and 5 species of parasitic mites from the family Laelapidae (n = 910), namely Laelaps agilis, Hyperlaelaps microti, Haemogamasus nidi, Eulaelaps stabularis and Myonyssus gigas. The dominant species of mite found on rodents was L. agilis (94.9%). Ixodes ricinus and L. agilis had similar overall host infestation prevalence. The values of abundance and mean intensity of infestation for I. ricinus and L. agilis varied between species of hosts and in different years, with the highest being for A. flavicollis, followed by M. glareolus, and M. minutus. [...]