S4-4 09:00 - 09:30 Cold wars and climate change: how host-pathogen interactions at low temperatures shape ectotherm success in changing environments. Ferguson, LV*; El Nabbout, A; Adamo, SA; Dalhousie University, Halifax, NS; Dalhousie University, Halifax, NS; Dalhousie University, Halifax, NS firstname.lastname@example.org
Changing winters will play an integral role in the outcome of infection and the transmission of disease in ectotherms. Ectotherms must balance investment in immunity with the response to cold, and winter triggers reconfigured states of immunity. Warmer and more variable temperatures during winter may change how insects and other arthropods invest in immune activity, impacting both energy use and protection against pathogens. Further, infection itself may modify host survival of low temperatures during the winter, and thus the spread and risk of disease in the growing season – including in vectors, such as ticks. For example, warming conditions in simulated winter conditions permitted black-legged ticks, Ixodes scapularis, to become active throughout the winter, which is likely to impact energy use and/or risk of contact with new hosts. Further, ticks infected with Borrelia burgdorferi were more likely to become active following exposure to subzero temperatures, compared to uninfected ticks. Thus, infection may improve the ability to recover from cold and variable winter conditions may favour the ability of infected ticks to find hosts and continue to spread disease. Overall, the impact of changing winters on ectotherm success may be mediated through infection, and winter is likely to play a role in shifting disease dynamics.