Meeting Abstract

P3-17    Movin’ on up: take-off performance in the orange sulphur butterfly, Colias eurytheme Thompson, SN*; Perlman, BM; Rourke, BC; California State University, Long Beach; California State University, Long Beach; California State University, Long Beach shyanne.thompson@student.csulb.edu

One of the constraints in Lepidopteran flight muscle performance is temperature. Flight is energetically expensive, so in order to produce enough power for take-off, ectothermic insects in a cool climate must have a strategy for warming their flight muscle, as thermal energy increases the frequency of muscle protein cross-bridge cycling. Warming behaviors include sun basking and shivering, while other adaptations enable flight to persist in lower temperature environments. Butterfly populations of Colias eurytheme live along an elevational gradient, where individuals living at higher elevations adapt to a cooler environment by having darker wings, thereby increasing absorption of solar radiation. Using high-speed cameras, we measured take-off velocity and acceleration to understand if these kinematic variables were affected by variable temperature conditions. Three different temperature regimes will be used to simulate warm, cool, and temperate climates, thus allowing for intraspecific comparisons of flight performance. We expect individuals from higher elevations (darker color morphs) to have increased kinematic measures of flight performance in cooler conditions compared to individuals from lower elevations (lighter color morphs). Compared to lighter color morphs at higher temperatures, we expect individuals from higher elevations (darker color morphs) to have decreased kinematic measures of flight performance as absorption of solar radiation is increased beyond what is useful, becoming deleterious for denaturable muscle proteins. Individuals will be put down and dissected after flight measurements, where molecular experiments will then be conducted to detect myosin isoforms in thoracic flight muscle using SDS-PAGE. With the onset of climate change, this study will help us understand potential elevational shifts of Colias populations.