Faculty Sponsor
Aimee Dunlap PhD
Final Abstract for URS Program
Caffeine (trimethylxanthine) is a synthetically and naturally produced stimulant that has been shown to elicit an effect on the central nervous system of humans as well as invertebrates. Although the exact mechanisms by which caffeine alters biological processes in invertebrates are still being investigated, its physiological and behavioral effects have been extensively documented. Naturally occurring caffeine is produced by certain flowering plants, including cocoa and tea species, and has been shown to influence invertebrate behavior, particularly cognitive performance and foraging patterns. In pollinating insects, the exposure to caffeine in floral nectar may affect how pollinators evaluate, select, and revisit food sources. Additionally, the effects of caffeine induced behaviors are impacted by important variables such as dosage and the timing of exposure. In this study, we examined the effects of caffeine dosage on the foraging efficiency of bumble bees (Bombus impatiens). Individual bees from a colony were tagged and subsequently trained to forage for a sucrose reward (60% M sucrose) using an artificial flower. Once trained, bees were independently assigned to different caffeine dosage treatments and placed under either a fixed ratio (FR) or progressive ratio (PR) schedule of reinforcement. The foraging behavior of treated and controlled bees was then recorded under isolated conditions. By comparing behavioral responses across varying caffeine dosages and reinforcement schedules, this study evaluated how differing caffeine exposure and reward ratios influence the foraging efficiency of bumble bees. The results of this study showcase the importance of the natural regulation of caffeine concentration within flowering plants, and the effects it induces on pollinators. This study has the potential to contribute beneficial data within the field of caffeine research.
Presentation Type
Visual Presentation
Document Type
Article