A new study has found caffeine can be used to help bees locate specific flowers. The research suggests the drug enhances bee memory and makes them more efficient at homing in on certain targeted flowers.
Many people couldn’t imagine getting started on a day’s work without first having a cup of coffee, and caffeine can be more than a mere stimulant. It helps one focus on the work they need to get done. And it turns out to have the same effect on bees.
Prior studies have demonstrated bees preferentially seeking out flowers that have been baited with caffeine. It had been hypothesized the bees were simply chasing a craving for a drug they enjoyed.
This new research set out to better understand the effect caffeine was having on the bees. Were the bees targeting a drug they craved, or was caffeine actually enhancing their memory of specific flowers, making them more efficient at getting that particular nectar?
"When you give bees caffeine, they don't do anything like fly in loops, but do seem to be more motivated and more efficient," says Sarah Arnold, corresponding author on the new study. "We wanted to see if providing caffeine would help their brains create a positive association between a certain flower odor and a sugar reward."
So instead of caffeinating a target flower the researchers primed the bees with caffeine in their nest. The experiment combined caffeine with a strawberry odored sugar solution.
The plan was to test whether the caffeine-doped bees better targeted artificial flowers with that same strawberry odor. As a comparison, a second group of bees were given the same strawberry solution without caffeine and a third group received an odorless sugar solution.
Given free rein in an experimental environment with two kinds of artificial flowers the caffeine-spiked bees preferentially homed in on the strawberry flowers in greater numbers compared to the other bees. Less than 45 percent of the sugar-only bees targeted the strawberry flowers, compared to over 70 percent of the caffeine bees.
The researchers also noted the caffeinated bees improved their flower visit speeds faster than the other groups. While the study was not specifically exploring the impact of caffeine on bee motor learning skills, the researchers do hypothesize the caffeine enhanced foraging efficiency and motivation.
Caffeine has been found to influence memory acquisition in humans, but this is the first evidence of it potentially enhancing bee behavior. The researchers say these findings could be of significant value to farmers.
Currently many farms purchase large volumes of pollinating bees every year. One recent study found only around one quarter of those bees visit the target crop, with the vast majority distracted by other nearby wildflowers. Arnold suggests using caffeine to prime the bees to focus on an intended crop could help both farmers and the surrounding natural ecosystem.
“… we leave wildflower resources for the wild bees, and the growers are getting more value for their money spent on the nests,” says Arnold. “It's a win-win solution for everybody."
The new study was published in the journal Current Biology.
Source: Cell Press