The effect of climate change and host plant quality on phenology and mortality of H. cunea

Climate change continues to have both direct and indirect effects on the health and abundance of species worldwide, including population declines, phenological mismatches throughout the food web and altered distribution of species. Heatwaves are occurring at a greater frequency as the Earth warms, and can have a variety of negative fitness effects, including mortality. Understanding how the performance of herbivorous insects may vary in response to a heatwave, based on host plant selection, is an intriguing area of investigation. The fall webworm (Hyphantria cunea) is a generalist herbivore native to North America and present as an invasive pest throughout Europe and Asia. In this study, we evaluate the effects of elevated temperature regimes and heat wave conditions (based on current climate predictions and temperature data from our study site) on fall webworm performance. Additionally, we examine the effect of low- and high-quality host plant use in each regime on the mortality and development time of fall webworm. Our work adds to the growing body of evidence that heatwaves have detrimental effects on individual populations and suggests that host plant use may be an important variable to consider.