Ecological parasitic infestation by Eutrombicula alfreddugesi (Acari: Tombiculidae) in Tropidurus hygomi (Squamata: Tropiduridae) from a Restinga habitat, Brazil northeastern

Abstract

In this study, we sought to investigate the parasitic relationship between chigger mites and Tropidurus, which, although close and frequent, still presents gaps in our knowledge of it, mainly regarding biotic (sex and life stage of the host) and abiotic (climate) factors. Every month over one year, we collected Tropidurus hygomi specimens in a conserved restinga area in northeastern Brazil. The hosts underwent biometric analysis, and their body surface was inspected for ectoparasites. We estimated the prevalence and mean infestation intensity, including for host life stage and sex. We applied a multiple response permutation procedure (MRPP) to assess statistical significance in infestation patterns for host life stage and sex, as well as seasonality. We estimated the body condition indices for each individual and used these values to infer their relationship with the respective parasitic load. We recorded a prevalence of 97.4% for E. alfreddugesi and a mean intensity of 49.40 ± 3.76 (range 1-313) mites, high rates consistent with those recorded for congeners of the host. Adult males were significantly more infested, and the mite pockets were the site with the highest infestation prevalence (96.89%) and intensity (45.02 ± 3.49). The patterns observed here can be explained mainly by morphological characteristics of mite pockets, due to T. hygomi sit-and-wait behavior and mite biology. Our findings provide greater understanding of the close evolutionary relationship between E. alfreddugesi and T. hygomi, without negative impacts for the host body.