Meeting Abstract
Acclimatization is an important mechanism for ectotherms to maintain homeostasis as environments become thermally stressful. Thermal regimes can be highly variable across the range of a species, and accordingly, populations can differ in their response to changing environmental conditions. The North American spread of the gypsy moth is an exemplar system for studying population variation in physiology after a rapid range expansion, as gypsy moth now occupies a wide gradient of climates across its invasive range. This study quantified differences in metabolic thermal sensitivity across temperature for two northern and two southern gypsy moth populations using stop-flow respirometry after acclimating larvae to high or low rearing temperatures. We measured the effect of rearing temperature on acclimation response of metabolic rate in each population, as well as the metabolic response of populations from the north and south range extremes when reared at the same temperature. Overall, there was a significant increase in metabolic rate with increasing respirometry temperature. These data do not provide evidence for metabolic adaptation to temperature based on population, as acclimation to rearing temperature was more predictive of metabolic rate than geographic origin of the population. Understanding the response of gypsy moth to temperature, particularly in populations at range extremes, is important for understanding future range dynamics in this species and in other invasive systems.
