Patterns of water mite and gregarine parasitism in Ischnura heterosticta (Odonata: Zygoptera) damselfly populations and their impact on body condition Ischnura heterosticta (Odonata: Zygoptera) damselfly populations and their impact on body condition

Parasitism is a strong selective agent that affects host fitness, and parasitism may be variable across often broad landscapes and ecological gradients. However, variation may also within small geographic areas due local differences in habitat and climate. Here, we quantified prevalence and intensity of ectoparasite water mite (Arrenurus sp.) prevalence, and endoparasite gregarine (Apicomplexa: Protozoa) prevalence in Australian common bluetail damselflies (Ischnura heterosticta) between sexes and across three populations in Cairns, Australia. We found more than 42% of the damselflies coinfected with water mites and gregarines. Parasitism of either parasite varied between sexes, being higher in females and they differed between the three populations. Further, we investigated how parasitism is correlated with damselfly body size, mass and lipid content. Water mite parasitism was negatively correlated with host body mass and lipid content, however, gregarine infected males and females had better body condition. In conclusion, our study suggests that damselflies having larger body size are more frequently selected by parasites, however, the impact on body mass and lipid content might vary with parasite type.