Optimization of adult performance determines host choice in a grass miner.

Models and empirical studies on host selection in plant-insect, algae-amphipod, host-parasite and prey-predator systems assume that oviposition preference is determined by the quality of the oviposition site for offspring development. According to the oviposition-preference-offspring-performance hypothesis, oviposition-preference hierarchy should correspond to host suitability for offspring development because females maximize their fitness by optimizing offspring performance. We show, we believe for the first time, that adult feeding site and related adult performance may explain most of the variation in adult feeding and oviposition site selection of an oligophagous grass miner, Chromatomyia nigra (Diptera). This study advances our understanding of the complex interactions between plants and herbivores because it shows that host-preference patterns are not only shaped by the optimization of offspring performance, as previously assumed, but also by the optimization of adult performance.