Caffeine improves memory in honeybees

Honeybees, like tired office employees, like their caffeine, suggests a new study finding that bees are more likely to remember plants containing the java ingredient. Caffeine occurs naturally in the nectar of coffee and citrus flowers. Bees that fed on caffeinated nectar were three times more likely to remember a flower’s scent than bees fed sugar alone. The findings, detailed in the journal Science, show how plants can manipulate animals’ memories to improve their odds of pollination. “Remembering floral traits is difficult for bees to perform at a fast pace as they fly from flower to flower, and we have found that caffeine helps the bee remember where the flowers are,” study leader Geraldine Wright, a neuroethologist at Newcastle University, UK, said in a statement. “Caffeine in nectar is likely to improve the bee’s foraging prowess while providing the plant with a more faithful pollinator,” Wright added. In their study, Wright and colleagues measured how much caffeine was in the nectar of three different species of the Coffea plant, including the “robusta” plant used to make freeze-dried coffee and the “arabica” plant used to make espresso and filter coffee. They also measured the amount of caffeine in four species of the Citrus plant: grapefruit, lemons, pomelo and oranges. All of these plants contained caffeine. Plants produce caffeine as a defense mechanism a bitter-tasting brew to fend off insects. Fortunately for the bees, the caffeine levels are below the threshold that they can taste, but high enough to affect their memory, the authors said.