Heritability of Flight Energetics and its Associated Traits in the Bumblebee Bombus Impatiens

Abstract

Recent studies suggest a possible correlated evolution of wing morphology, wing beat frequency, muscle biochemistry and flight metabolic rate in bees. In order to investigate the degree to which natural selection can act on these traits, an estimation of heritability was required. Commercial and laboratory reared colonies from wild caught queens were used to estimate narrow-sense (h2) and broad-sense (H2) heritability of flight metabolic rate and its associated traits in the bumblebee Bombus impatiens. h2 estimates obtained from parent-offspring regressions were not statistically significant. H2 estimates were significant for morphological traits (body mass and wing morphology) as well as whole-animal traits (flight and resting metabolic rate, wing beat frequency) in both populations. We suggest that queens have a decrease in flight performance as a result of a trade-off between flight and fecundity, explaining the lack of significance in parent-offspring regressions.