Eastern monarch larval performance may not be affected by shifts in phenological synchrony with milkweed

1. Interacting species are experiencing disruptions in the relative timing of their key life history events due to climate change. These shifts can sometimes be detrimental to the fitness of the consumer in trophic interactions but not always.
2. The potential consequences of phenological asynchrony for the monarch butterfly (Danaus plexippus) and its host plant (Asclepias spp.) have not been well studied. Given that plants generally undergo seasonal declines in quality, if climate change delays the timing of the larval stage relative to the availability of younger milkweed plants, monarch performance could be negatively affected.
3. Here we explore the potential consequences for the eastern monarch population due to probable asynchrony with milkweed. We used field surveys around Ottawa, Canada to determine monarch oviposition preference on common milkweed (Asclepias syriaca) plants and the seasonal availability of these plants. To determine the potential fitness consequences when femal...