Effects of Macrocheles mites on longevity of males of the dimorphic dung beetle Onthophagus binodis

In this study we tested the nature of the phoretic relationship between the cosmopolitan mite Macrocheles merdarius and the dimorphic dung beetle Onth ophagus binodis. We observed and experimentally manipulated the number of m ites on individual beetles and tested how mite infestation affects male lon gevity. There was a significant effect of mites on male longevity: males in our mites-added treatment died on average 15 days earlier than males in ou r mites-removed treatment. Interestingly, the number of mites on males was significantly repeatable suggesting that individuals may differ in their su sceptibility to infestation. Major males had more mites on them than minor males, and the proportion of mites on minor males was negatively density de pendent.