<p><strong>Distribution and infestation of gamasid mite <em>Laelaps echidninus</em> (Mesostigmata: Laelapidae) on small mammals across five provincial regions of southwest China</strong></p>

This study investigated the distribution and infestation patterns of the gamasid mite Laelaps echidninus (Mesostigmata: Laelapidae) on small mammals in southwest China to provide a scientific basis for the surveillance of mite-borne zoonoses. Prevalence (PM), mean abundance (MA), and mean intensity (MI) were calculated, and Taylor's power law was applied to characterize the spatial distribution pattern. A total of 38,423 L. echidninus mites were collected from 4,351 small mammals representing 29 species, with 99.65% recovered from rodents. Rattus nitidus exhibited the highest PM (67.35%) and MA (9.33 mites per host) (P < 0.001). Male, and adult hosts showed significantly higher infestation indices, particularly MI, than female, and juvenile hosts (P < 0.05), respectively. Infestation varied markedly among environments. Adult females, and adults greatly outnumbered males, and juveniles, respectively, and the mite population displayed an aggregated distribution among hosts. Laelaps echidninus is widely distributed in southwest China, with rodents as its primary hosts; host sex- and age-related biases, together with environmental heterogeneity, strongly influence infestation dynamics, with adult females dominating the mite population.