Data for: Thermoregulation enhances survival but not reproduction in a plant-feeding insect

Temperature influences nearly all aspects of fitness. However,
reproduction is often more thermally sensitive than survival.
Thermoregulation must maintain performance in both components of fitness
to buffer populations from environmental change. We assessed the
fitness benefits of thermoregulation in Enchenopa binotata
treehoppers. Under realistic mesocosm conditions, we quantified fine-scale
microclimates using 3D-printed operative temperature models. We then
compared operative temperatures to treehopper body temperatures and
translated patterns of thermoregulation into variation in survival and
reproduction. We also assessed two thermoregulatory mechanisms: precise
microclimate choice and heat escape behaviors. Finally, we applied our
results to evaluate if arthropod thermoregulation is accurately
characterized by two theoretical models commonly used to simulate
responses to environmental change. We found substantial thermal
variation at fine spatial scales relevant to insects: at a single point in
time, temperatures within 30cm-tall plants spanned ranges up to 19ºC
(23-42ºC). Lethal operative temperatures were common when air
temperatures were high. However, heat escapes allowed treehoppers to
almost entirely avoid lethal temperatures. By contrast, individuals
thermo-conformed in the absence of lethal operative temperatures. This
finding suggests that precise microclimate choice imposes high costs due
to thermal uncertainty at fine spatial scales. Furthermore, given the
narrow range of temperatures in which reproduction occurs,
thermoregulation is unlikely to maintain reproduction. Thermoregulation
was most effective in the lowest-quality and most spatially variable
thermal habitats. Treehopper thermoregulation therefore more closely
follows cost-benefit models of thermoregulation compared to models that
account for inhibited movement at extreme temperatures. Overall,
even if thermoregulation can prevent lethal heat stress, thermoregulation
may have limited capacity to buffer arthropods and other small ectotherms
from environmental change if it cannot maintain reproductive performance.