Discussion
While we recognize that climate change is altering phenological
relationships among interacting species, the consequences for species
interactions in different community contexts are unclear (Forrest &
Miller-Rushing 2010). Here we show that delays in the emergence of
parasitoids, relative to their insect hosts, significantly alters the
strength and persistence of host-parasitoid interactions; and the
magnitude of these effects varied across temperatures and the community
context in which the interaction took place. Importantly, modifications
in the outcome of the host-parasitoid interaction were due to both
changes in host development times and declines in host and parasitoid
performance under warming, irrespective of shifts in development rates.
Taken together, these findings demonstrate that modifying the effects of
phenological shifts on host-parasitoid interactions, via community
contexts, could help maintain availability of prey (e.g., adaptive
capacity) when hosts and parasitoids become temporally mismatched, but
these benefits may not be realized in predicted warmer environments due
to significant declines in performances of hosts and parasitoids. Thus,
accounting for interactive effects between climate and community context
is necessary when trying to predict the immediate and long-term
consequences of phenological shifts on biotic communities.