Feeding evolution of a herbivore influences an arthropod community through plants: implications for plant-mediated eco-evolutionary feedback loop

1. Genetic variation in individual species can have important ecological consequences, and sometimes, these interactions are mediated through another species. For example, genetic variation in an herbivore could alter plant responses that then influence other plant-associated arthropods. However, few systems have experimentally tested the ecological consequences of genetic variation as mediated through other species, especially within the same trophic community context. 2. I studied how evolution of feeding preference in the willow leaf beetle (Plagiodera versicolora), which occurs under selection in a herbivore community context, feeds back to an arthropod community through plant-mediated indirect interactions. Previous studies show beetle populations locally adapt distinct preferences ranging from the gourmet-type, which feeds exclusively on new leaves of willows, to the no-preference (no-pref) type, which displays non-preferential feeding on leaves of different ages. 3. I conducted f...