Larval nutrition impacts the scaling of adult metabolic rate with body mass in honeybees

Resting metabolic rate (RMR) is a fundamental physiological measure linked
to numerous aspects of organismal function, including lifespan. Although
dietary restriction in insects during larval growth/development affects
adult RMR, the impact of larval diet quality on adult RMR has not been
studied. Using in vitro rearing to control larval diet quality, we
determined the effect of dietary protein and carbohydrate on honeybee
survival-to-adulthood, time-to-eclosion, body mass/size and adult RMR.
High carbohydrate larval diets increased survival-to-adulthood and
time-to-eclosion compared to both low carbohydrate and high protein diets.
Upon emergence, bees reared on the high protein diet were smaller and
lighter than those reared on other diets, whilst those raised on the high
carbohydrate diet varied more in body mass. Newly-emerged adult bees’
reared on the high carbohydrate diet showed a significantly steeper
increase in allometric scaling of RMR compared to those reared on other
diets. This suggests that diet quality influences survival-to-adulthood,
time-to-eclosion, and the allometric scaling of RMR. Given that
agricultural intensification and increasing urbanisation have led to a
decrease in both forage availability and dietary diversity for bees, our
results are critical to improving understanding of the impacts of poor
developmental nutrition on bee growth/development and physiology.