Figure 3. The survival of host larvae infected with bacterial strains differing their evolutionary histories.

Survival of host larvae when infected with bacteria that evolved in the absence (open symbols) or presence (grey symbols) of PPV-phage in a 25°C (circles) or 37°C (triangles) during the microcosm experiment. Black squares denote the ancestral S. marcescens strain and diamonds the water controls. Selection due to high temperature increases bacterial virulence but only in the absence of phage.