Invited review - Evolutionary ecology of water mite-insect interactions: acritical appraisal

Water mites are ubiquitous parasites in freshwater ecosystems. The interact ion between water mites and aquatic insects has been scarcely studied from an evolutionary ecology viewpoint. Host finding is an important feature of the water mite's life cycle. The ho st finding success is suggested to depend upon host behaviour and quality. Water mite parasitism lowers host fitness via different routes: by draining nutrients hosts can suffer from decreased fecundity, increased mortality e tc. Host sexes and closely related species are affected differently. Recent studies on host fitness, whilst taking the parasite behaviour into account , revealed results contrasting older studies where knowledge of the parasit es' life cycle was absent. The potential for coevolution is discussed. For exploring evolutionary trends a water mite phylogeny is needed. Water mite- aquatic insect interactions can be assumed to provide excellent conditions to conduct experimental studies on direct and indirect effects of multiple natural enemies in freshwater ecosystems.