Caffeine acts as a stimulant, helping wake humans up and keep alert. Caffeine also has a beneficial effect on bumblebees, enhancing their memory.
Bees also like caffeine. Previous studies showed that bees visit caffeinated flowers more often. Researchers from the National Resources Institute and the Horticultural Research at East Malling in the UK decided to find out why caffeine is so alluring. The group tested 86 bumblebees in their experiment. The first group received a caffeinated sugar solution with a strawberry odor. The second group received a sugar solution along with the strawberry odor. The final group just got the sugar solution.
When these bees were let loose, they could choose between landing on flowers with strawberry odors or other flowers. The first two groups associated the sugar solution with strawberry odors, and visited the strawberry flowers more often. Remarkably, caffeine improved the ability of bees to associate the strawberry odor with the sugary reward. They visited strawberry flowers first, more than any other group. The results were published in Current Biology in July.
Farmers usually buy dozens of boxes of bumblebees every year, to help pollinate strawberries. Unfortunately, bees often head over to neighboring wildflowers. Using caffeine could help make agricultural bees more efficient at pollinating strawberries.