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

We examined whether host damselflies (Ischmura verticalis) in different sta ges 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 damselflie s closer to emergence and damselflies closer to emergence should spend more time defending against mites. We found that mites colonised damselflies cl oser to emergence in one of two experiments, but that damselflies in differ ent stages of development did not differ in time spent defending against mi tes. (C) 1999 Australian Society for Parasitology. Published by Elsevier Sc ience Ltd. All rights reserved.