Genetic differentiation associated with host plants and geography among six widespread species of South American Blepharoneura fruit flies (Tephritidae)

Tropical herbivorous insects are astonishingly diverse and many are highly host-specific. Much evidence suggests that herbivorous insect diversity is a function of host-plant diversity; yet, the diversity of some lineages exceeds the diversity of plants. Although most species of herbivorous fruit flies in the Neotropical genus Blepharoneura are strongly host-specific (they deposit their eggs in a single host plant species and flower sex), some species are collected from multiple hosts or flowers and these may represent examples of lineages that are diversifying via changes in host use. Here, we investigate patterns of diversification within six geographically widespread Blepharoneura species that have been collected and reared from at least two host-plant species or host-plant parts. We use microsatellites to: 1) test for evidence of local genetic differentiation associated with different sympatric hosts (different plant species or flower sexes); and 2) examine geographic patterns of ge...