Abstract

The biogeography of organisms, particularly those with complex lifestyles that can affect dispersal ability, has been a focus of study for many decades. Most Hydrachnidia, commonly known as water mites, have a parasitic larval stage during which dispersal is predominantly host-mediated, suggesting that these water mites may have a wider distribution than non-parasitic species. However, does this actually occur? To address this question, we compiled and compared the geographic distribution of water mite species that have a parasitic larval stage with those that have lost it. We performed a bootstrap resampling analysis to compare the empirical distribution functions derived from both the complete dataset and one excluding the extreme values at each distribution tail. The results show differing distribution patterns between water mites with and without parasitic larval stages. However, contrary to expectation, they show that a wider geographic distribution is observed for a greater proportion of the species with a non-parasitic larval stage, suggesting a relevant role for non-host-mediated mechanisms of dispersal in water mites.