Meeting Abstract
Climate change is increasing the frequency of heat waves and other extreme weather events experienced by organisms. How do the number and developmental timing of heat waves affect survival, growth and development of insects? Do heat waves early in development alter performance later in development? We addressed these questions using experimental heat waves with larvae of the Tobacco Hornworm, Manduca sexta. The experiments used diurnally fluctuating temperature treatments differing in the number (0-3) and developmental timing (early, middle and/or late in larval development) of heat waves, in which a single heat wave involved three consecutive days with a daily maximum temperature of 42 °C. Multiple (but not single) heat waves significantly reduced survival to pupation and pupal mass; the best model for the data indicated that both the number and developmental timing of heat waves affected performance. In addition, heat waves earlier in development significantly reduced growth and development rates later in larval development. Our results show that repeated, sublethal heat waves can have continuing and cumulative negative consequences for insects.
