Parasitic Infestation Patterns of Water Mites (Arrenurus spp.) on Odonata Species in North African Freshwater Habitats

Abstract

This study investigates the parasitic relationship between water mites and Odonata species in a lotic environment in Souk Ahras, analyzing 27 species including both Zygoptera and Anisoptera. Over a two-year period, we recorded 744 parasitic larvae on 110 individuals belonging to four Zygoptera species: Platycnemis subdilatata (Selys, 1849), Coenagrion caerulescens (Fonscolombe, 1838), Coenagrion mercuriale (Charpentier, 1840), and Ischnura graellsii (Rambur, 1842). Generalized linear model revealed significant differences in infestation levels based on species and body parts, while sex differences were not significant. P. subdilatata exhibited the highest infestation rate of 2.74%, accounting for 75 infested individuals. In contrast, C. caerulescens, C. mercuriale, and I. graellsii showed lower prevalence rates of 1.28%, 1.01%, and 0.95%, respectively. Mites were predominantly found attached to the thorax, probably because it provides better survival chances and more favorable conditions for larval development. Our findings highlight a strong host preference by water mites, indicating that only certain damselflies serve as hosts, thus contributing to the understanding of parasitism dynamics in freshwater ecosystems.