Infestation of chigger mites on Chinese mole shrew,Anourosorex squamipes, in Southwest China and ecological analysis

Abstract

The Chinese mole shrew,Anourosorex squamipesMilne-Edwards, 1872, is a common species of insectivorous mammal in Southwest China. Based on field investigations between 2001 and 2019, the present study reports the infestation of chiggers (larvae of chigger mites) on the shrew in Southwest China and certain ecology parameters for the first time. A total of 3169 chiggers were collected from 1694A. squamipesand they were identified into 72 species and 10 genera in the family Trombiculidae. The overall infestation prevalence (Pm), mean abundance (MA) and mean intensity (MI) ofA. squamipeswith chiggers reached 11.1%, 1.87 and 16.86, respectively. The species diversity, species composition and infestation of chiggers onA. squamipesfluctuated in different environments (latitudes, altitudes, habitats and landscapes) and on different sexes and ages of the shrew hosts with high heterogeneity and low species similarity. In the established linear regression equation (M* = 0.173 + 1.054 M) for dominant miteLeptotrombidium densipunctatum, both theαandβvalues (α = 0.173,β = 1.054) exceeded the boundary values (F = 4.67,p < 0.05), and therefore the spatial distribution pattern of this mite was determined as an aggregated distribution among different individuals of shrew hosts. The species abundance distribution of the chigger community onA. squamipesconformed to the lognormal distribution, and its curve showed a gradually descending tendency from the rare mite species to the dominant mite species. The curve tendency of species-sample relationship implies that more species of chiggers would be found if the host samples infinitely keep increasing.