Meeting Abstract
Previous work suggests elevated winter temperature speeds the onset of post-winter development as well as negatively impacting survival and potential fecundity. However, these studies typically used constant exposure temperature with less consideration of the potentially important contribution of diurnal variation. To determine the effect of variable winter temperature on the above parameters, we compared pupation date, survival, and potential fecundity in the goldenrod gall fly, Eurosta solidaginis, exposed to constant, average monthly temperature or diurnal cycles that fluctuated between monthly low and high temperature (average-constant or average-variable groups). In addition, to assess the effect of elevated winter temperature we subjected larvae to constant temperature and a diurnally fluctuating regime as predicted by a climate change model (elevated-constant or elevated-variable treatment). Elevated winter temperature sped development as larvae exposed to constant, elevated temperature had a median date of pupation of March 24, which occurred 13, 24, and 36 days before those in the elevated-variable, average-variable, or average-constant treatments respectively. Levels of adults displaying a righting response five days after eclosion was greatest in those subjected to the elevated-variable treatment (54%), while the remaining groups averaged only 30%. Exposure to variable winter temperature preserved potential fecundity as females in the elevated-variable and constant variable treatments produced and average of 148 ± 14 eggs compared to just 104 ± 9 eggs in the constant temperature treatments. In sum, elevated winter temperature sped the onset of spring development, while variable temperature regimes enhanced survival and potential fecundity.
