Data from: Developmental timing of extreme temperature events (heat waves) disrupts host-parasitoid interactions

1. When thermal tolerances differ between interacting species, extreme
temperature events (heat waves) will alter the ecological outcomes. The
parasitoid wasp Cotesia congregata suffers high mortality when reared
throughout development at temperatures that are non-stressful for its
host, Manduca sexta. However, the effects of short-term heat stress during
parasitoid development are unknown in this host-parasitoid system. 2.
Here, we investigate how duration of exposure, daily maximum temperature,
and the developmental timing of heat waves impact the performance of C.
congregata and its host¸ M. sexta. We find that the developmental timing
of short-term heat waves strongly determines parasitoid and host outcomes.
3. Heat waves during parasitoid embryonic development resulted in complete
wasp mortality and the production of giant, long-lived hosts. Heat waves
during the 1st-instar had little effect on wasp success, whereas heat
waves during the parasitoid’s nutritionally and hormonally critical 2nd
instar greatly reduced wasp emergence and eclosion. The temperature and
duration of heatwaves experienced early in development determined what
proportion of hosts had complete parasitoid mortality and abnormal
phenotypes. 4. Our results suggest that the timing of extreme temperature
events will be crucial to determining the ecological impacts on this
host-parasitoid system. Discrepancies in thermal tolerance
between interacting species and across development will have important
ramifications on ecosystem responses to climate change.