D3416: Climate change-mediated variation in diet for an outbreaking forest defoliator: Impacts on insect disease and implications for pest management

Climate change can lead to phenological asynchrony between forest insects and host trees, impacting the quality and quantity of plant tissue available for consumption. This can alter the population dynamics of forest insects directly and can also have cascading impacts at higher trophic levels. Pathogens and diseases play a critical role in forest insect population dynamics and the impact of phenological shifts on this group of natural enemies is poorly understood. Host plant-mediated variations in disease pathogenicity is a relatively common phenomenon among herbivorous insects and variable responses of forest defoliators to disease-causing agents may have important implications for forest pest management. The objectives of this research were to examine the interactive effects of climate change-mediated variation in diet and microsporidial disease on forest tent caterpillar Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae) mortality and sublethal effects. This research is among the first studies to evaluate the impact of climate-change induced phenological asynchrony on forest insect disease pathogenicity.