Local resource heterogeneity drives density-dependent dispersal expression in a phoretic mite

This research examines the role of local environmental heterogeneity on the expression of a dispersal phenotype in the phoretic mite Rhizoglyphus robini. To test this, 30 populations of mites were given either homogenous, heterogenous, or intermediate food distributions, and either a high or low competition treatment. This creates 6 unique treatment combinations, of which there are 5 replicates. These treatments were maintained over an 18 week experiment (approximately 9 generations). We find that heterogenous food distributions induce greater dispersal under high competition, but not under low competition, and dispersal expression overall reduces with time.