Infestation and distribution of chigger mites on Confucian white-bellied rat ( Niviventer confucianus ) in Southwest China

Based on the field investigation in five provincial regions of Southwest China between 2001 and 2019, the present paper reports the infestation and distribution of chigger mites on the Confucian white-bellied rat Niviventer confucianus in China for the first time. A total of 11,017 chigger mites were collected from the body surface of 911 N . confucianus rat hosts, and 10,161 of them were identified as 166 species and 16 genera in three subfamilies under two families with high species diversity ( S = 166, H’ = 3.19, E = 0.62). Of 911 N . confucianus rats, 341 individuals were infested with chiggers with high overall prevalence ( P M = 37.43%), mean abundance ( MA = 12.09 mites/rat) and mean intensity ( MI = 32.31 mites/rat). On the body surface of N. confucianus , Ascoschoengastia sifanga was the most dominant chigger species followed by Walchia ewingi and Leptotrombidium rupestre . All the three dominant chigger species showed an aggregated distribution pattern among different individuals of N. confucianus . Chigger infestations on the same rat host ( N. confucianus ) showed some heterogeneity under different environmental conditions such as latitudes, longitudes, altitudes and landscapes. Based on Preston's lognormal model, the species abundance distribution of chiggers on N. confucianus conformed to a lognormal distribution pattern, and the predicted total species of chiggers on N. confucianus in Southwest China was estimated to be 228 species.