Wild strawberry shows genetic variation in tolerance but not resistance to a generalist herbivore

Plants’ defenses against herbivores usually include both resistance and tolerance mechanisms. Their deployment has predominantly been studied in either single plant genotypes, or multiple genotypes exposed to single herbivores. In natural situations, however, most plants are attacked by multiple herbivores. Therefore, aims of this study were to assess and compare effects of single and multiple herbivores on plant resistance and tolerance traits, and the consequences for overall plant performance. For this, we exposed multiple genotypes of wild woodland strawberry (Fragaria vesca) to jasmonic acid (JA), to mimic chewing herbivory and induce the plants’ defense responses, then introduced the generalist herbivore Spodoptera littoralis to feed on them. We found that woodland strawberry consistently showed resistance to S. littoralis herbivory, with no significant genetic variation between the genotypes. By contrast, the studied genotypes showed high variation in tolerance, suggesting evolut...