Host specificity and permanence of associations between mesostigmatic mites (Acari: Anactinotrichida) and burying beetles (Coleoptera: Silphidae:Nicrophorus)

We examined the host specificity of mesostigmatic mites associated with sympatric species of burying beetles. Using field collections we established attachment patterns, prevalence and intensity of the mites phoretic on the beetles, and tested for host-specific differences. Further, to test whether the mites have established permanent associations and reproduce in the brood chamber of the beetles, we performed breeding experiments. The beetles carried the dispersal stages of seven mesostigmatic mite species, belonging to four genera: Poecilochirus (Parasitidae), Macrocheles (Macrochelidae), Neoseius (Uropodina) and Alliphis (Eviphididae). Generally, only one developmental stage of each mite species was phoretic, but exceptions occurred. The data suggest that all mite species except M. merdarius have established close associations with the beetles because they attach to specific locations on the beetle, reach extremely high prevalence values and are host-specific even within the genus Nicrophorus. Our breeding experiments show that most of the mite species reproduce in the brood chamber of the beetles, which indicates that they live in permanent association with their hosts. A. necrophilus disperses from the brood chamber by attaching to the beetle offspring, whereas the Poecilochirus spp. and probably also M. nataliae gain time by leaving on the parent beetles.