Spatial turnover in host-plant availability drives host-associated divergence in a South African leafhopper (Cephalelus uncinatus).

Background: The evolution of reproductive isolation between herbivorous insect populations is often initiated by shifts to novel host-plants, a process that underlies some of the best examples of ecological speciation. However, it is not well understood why host-shifts occur. Arguably the most common hypothesis is that host-shifts occur in response to competition, while a less frequently invoked hypothesis is that herbivores adapt locally to geographic differences in potential host-plant communities.

Experimental evidence for fundamental, and not realized, niche partitioning in a plant-herbivore community interaction network.

Patterns of niche partitioning can result from local ecological interactions (e.g. interspecific competition) occurring within a contemporary time frame (realized niche partitioning).