Context-Dependent Reproductive Isolation: Host Plant Variability Drives Fitness of Hybrid Herbivores.

AbstractThe role of divergent selection between alternative environments in promoting reproductive isolation (RI) between lineages is well recognized. However, most studies view each divergent environment as homogenous, thereby overlooking the potential role within-environment variation plays in RI between differentiating lineages. Here, we test the importance of microenvironmental variation in RI by using individual trees of two host plants, each harboring locally adapted populations of the cynipid wasp .