High prevalence and intensity of infestation of Eutrombicula alfreddugesi (Acarina: Trombiculidae) on Tropidurus torquatus (Squamata, Tropiduridae): effects of body size and on body condition across ten populations along the Brazilian coast

Abstract

We investigated the infestation of Eutrombicula alfreddugesi mites on Tropidurus torquatus lizards across ten coastal populations in Brazil to evaluate variations among localities and relationships with intrinsic features of hosts (body size and body condition). For each population, we calculated the prevalence of infestation and the mean number of mites per host (mean intensity of infestation). Lizards from all populations were infested by mites, with prevalence ranging from 95.6 to 100%. Mean intensities of infestation also were always high, ranging from 55.3 ± 88.8 to 280.9 ± 208.2 mites per lizard. The lizard body regions most intensely used as microhabitat by mites were the axillae and neck (which bear “mite pockets” in T. torquatus). In most populations, the number of mites tended to increase with the body size of hosts. The body condition of hosts and the intensity of infestation were positively correlated, considering the total sample (i.e. lizards of all populations pooled). The main microhabitats (i.e., body regions) used by E. alfreddugesi on T. torquatus represented total intensities of infestation, suggesting that counting mites on these body regions provide a useful index to estimate the overall intensity of infestation. Lizards are suitable and predictable resources for parasitic mites, which take advantage of ecological and morphological features of host individuals and species, with large body sizes, imbricated and keeled scales, and presence of skin folds and mite pockets favoring occupation and high intensities of infestation by mites.