Infestation and Distribution Patterns of Ectoparasites on the Red-Eared Harvest Mouse (Micromys erythrotis) in Southwest China

Given the paucity of research on the red-eared harvest mouse (Micromys erythrotis) and its associated ectoparasites, this study aims to illustrate the infestation and distribution patterns of ectoparasites on this mouse in southwest China. A retrospective analysis was conducted based on field investigations and taxonomic identification across five provinces in southwest China between 2000 and 2024. Infestation indices, spatial distribution indices, and generalized linear mixed models (GLMMs) were used for analysis. From the 273 M. erythrotis captured, 1349 ectoparasites were identified comprising 54 species, including nine species of vectors or potential vectors in the transmission of specific zoonotic pathogens. The overall infestation indices were PM= 66.30%, MA = 4.94, and MI = 7.45. Sucking lice accounted for the highest number of parasite individuals (Cr= 45.59%), whereas gamasid mites exhibited the highest species richness (S = 24). All spatial distribution indices exceeded the critical values for an aggregated distribution. Adult hosts exhibited higher infestation than juveniles. Co-infestation with two or more parasite groups was observed in 29.30% of M. erythrotis individuals. In conclusion, M. erythrotis individuals were infested with diverse species of ectoparasites, dominated by sucking lice and gamasid mites. The coexistence of multiple vector species may have potential significance in epidemiology.