Ectoparasitic insects and mites on Yunnan red-backed voles (Eothenomys miletus) from a localized area in southwest China

Abstract

Ectoparasitic insects and mites on Yunnan red-backed voles (Eothenomys miletus) in Dali prefecture, Yunnan Province, southwest China, were studied between 2003 and 2004. In total, 34,389 individuals of 86 species of ectoparasitic insects (seven species of fleas and five species of sucking lice) and mites (23 species of gamasid mites and 51 species of chigger mites) were collected from 916 individual hosts. The diversity of ectoparasites on this single rodent species in such a small area was much higher than in previous reports, which concerned more host species and greater geographical areas. The majority of the ectoparasites were chigger mites, which accounted for 59.3% of the parasite species and 87.4% of the individual parasites. Most voles harbored parasites with an overall prevalence (P) of 82.5% and mean abundance (MA) of 37.5 parasites per host. The dispersion coefficient (C) and patchiness index (m*/m) were used to study the spatial patterns of the seven dominant parasite species, and all seven had aggregated distributions. The species abundance distribution of the ectoparasites on the vole was fitted by Preston's lognormal distribution (R (2) = 0.82), and the total expected parasite species was estimated from this plot as 167 species. Yunnan red-backed voles harbor many ectoparasites as revealed by examination of a large host population. Future field investigations should sample large numbers of host individuals to assess ectoparasite populations.

Analysis of ectoparasites (chigger mites, gamasid mites, fleas and sucking lice) of the Yunnan red‐backed vole (Eothenomys miletus) sampled throughout its range in southwest China

“…The consistency in these results confirms that chigger mites and gamasid mites are predominant ectoparasites on the vole. In comparison with previous work conducted in a more localized area (Guo et al ., , the present study covered the entire range of distribution of E. miletus and found many more species of parasite than did the earlier study. The extensive sampling and the comparatively large host sample makes the present results more stable and allowed for the collection of many species of parasite, including some rare species which may not be found in a localized collection with a limited host sample.…”

“…Moreover, some species of gamasid mite [e.g. of the genera Cosmolaelaps , Hypoaspis , Gymnolaelaps , Macrocheles , Holostaspella , Euryparasitus , Vulgarogamasus , Parasitus , Lasioseius , Proctolaelaps , Neparholaspis , Gamasholaspis , Pachylaelaps and Sinoseius (Table )] are actually free‐living species in soil, litter and humus (Pan & Deng, ; Radovsky, ; Guo et al ., ; Huang et al ., ) and thus are not true ‘ectoparasites’. These free‐living gamasid mites may have crawled onto the body surfaces of voles by accident.…”

“…These free‐living gamasid mites may have crawled onto the body surfaces of voles by accident. This also increases the number of ‘parasite’ species on E. miletus (Guo et al ., ; Huang et al ., ).…”

“…Gamasid mites were the second common taxa of ectoparasites on E. miletus . These results are consistent with those of previous reports (Guo et al ., ) and reflect the overall status of ectoparasite infestation on E. miletus . The consistency in these results confirms that chigger mites and gamasid mites are predominant ectoparasites on the vole.…”

“…Of these provinces (Yunnan, Sichuan and Guizhou), Yunnan represents the main and most important region of distribution of E. miletus (Yang & Yang, ; Luo, ; Luo et al ., ; Zhu et al ., , , ). Eothenomys miletus is also described as the ‘Yunnan Chinese vole’ and the ‘large oriental vole’ (Luo, ; Huang et al ., ; Guo et al ., ), and is known to harbour many fleas, sucking lice, chigger mites and gamasid mites on its body surface (Guo et al ., ). Eothenomys miletus has been identified as a pest species because it is harmful to agricultural fields and forests in its regions of distribution.…”