Grooming decisions by damselflies, age-specific colonisation by water mites, and the probability of successful parasitism.

We examined whether host damselflies (Ischnura verticalis) in different stages of development were differentially susceptible to parasitism by larval water mites (Arrenurus pseudosuperior). We found that mites were successful in reaching the parasitic phase more often if they colonised hosts closer to emergence. Thus, we predicted that more mites should colonise damselflies closer to emergence and damselflies closer to emergence should spend more time defending against mites. We found that mites colonised damselflies closer to emergence in one of two experiments, but that damselflies in different stages of development did not differ in time spent defending against mites.