Investigating nectar rhythms in squash (Cucurbita pepo): Effects on honey bee (Apis mellifera) foraging behavior

Honey bee foragers are able to optimize foraging behavior by monitoring changes in the components of nectar and by learning the times of day at which flowers secrete nectar. Forager bees schedule their flight behavior (via the circadian clock-driven time-sense) to match the times of availability of productive nectar sources (also expressed as a circadian rhythm). We have determined that greenhouse-grown squash (Cucurbita pepo) flowers exhibit a consistent daily nectar secretion rhythm: flowers open just before sunrise (exhibiting low volume but high sugar concentration) and close at midday (with high volume and relatively low concentration). The current study is designed to determine (1) how the nectar rhythm responds to a variety of environmental conditions and (2) what physical factors associated with the nectar (volume, concentration, total sugar content, etc.) are used by the bees to trigger their time-memory.