Figure 3.

Ampelomyces can be locally adapted to its mildew host. Hyperparasite infectivity and infection severity strongly varied among hyperparasite strains (individual plots) and between sympatric/allopatric mildew hosts. Statistical analysis suggests that Ampelomyces was more infective against sympatric mildew than the mean of all allopatric combinations; however, the presence and intensity of this effect varied greatly among hyperparasite genotypes. This could indicate that selection for local adaptation varies in strength across the metapopulation, or that the strength of selection is highly dynamic over evolutionary time.