Parasite‐mediated sexual selection in a damselfly

Sexual selection can improve population fitness and purge deleterious mutation from the gene pool by promoting condition-dependent mate selection. One ecological factor that reduces individual condition is parasitism. Parasitism tends to increase hosts' load likely indicates inferior host genetic quality. Parasite-mediated selection, therefore, should favour mating success of parasite-resistant individuals over parasitised individuals. We tested this hypothesis in male Agriocnemis pygmaea damselflies, which are Arrenurus water mites. calculated frequency (i.e. proportion parasitism) intensity number parasites per individual) parasitism free-flying males copula seven natural populations. predicted observed will be less than expected based on population. further parasite would lower caught single males. found were significantly non-parasitised males, independent their occurrence frequency. However, there was no difference average between captured or Our study shows addition sexual a strong agent against implies it could promote local adaptation counteract driven extinction risks.