The developmental race between maturing host plants and their butterfly herbivore – the influence of phenological matching and temperature

1. Interactions between herbivorous insects and their host plants that are limited in time are widespread. Therefore, many insect–plant interactions result in a developmental race, where herbivores need to complete their development before plants become unsuitable, while plants strive to minimize damage from herbivores by outgrowing them. 2. When spring phenologies of interacting species change asymmetrically in response to climate warming, there will be a change in the developmental state of host plants at the time of insect herbivore emergence. In combination with altered temperatures during the subsequent developmental period, this is likely to affect interaction strength as well as fitness of interacting species. 3. Here, we experimentally explore whether the combined effect of phenological matching and thermal conditions influence the outcome of an insect–host interaction. We manipulated both developmental stages of the host plants at the start of the interaction and temperature du...