Meeting Abstract
Research on overwintering insects often focuses on their tolerance to abiotic stress. However, animals are also part of complex ecological webs, including a range of pathogens that can threaten survival. Previous work hinted at an upregulation of insect immunity after cold exposure, so we explored the thermal biology of insect immunity more closely by determining 1) which components of the immune system are upregulated by cold; 2) whether acclimation affects the shape of the thermal performance curve for immune responses; and 3) how the phenotypic plasticity of the host and the pathogen interact to determine the outcome of infection in a complex thermal landscape. We show that while cold exposure activates potential immunity in Drosophila, it does not appear to affect the fly’s ability to fight off pathogens. We found that low temperature acclimation leads to a paradoxical narrowing of the thermal performance curve of some measures of immunity, and that phenotypic plasticity by a pathogen can negate any inherent advantages a host might gain through acclimation. Together, this demonstrates that the temperature-immune interaction is complex, and often counter-intuitive, but that the outcome of that complexity may not undermine attempts to predict responses to climate change based on thermal biology.
