It’s not just people who perform better with a serving of caffeine, a new study suggests.
Researchers at the University of Greenwich report that bumblebees learn more effectively when their nectar is laced with the powerful stimulant.
Added caffeine was able to help the bees better remember the scent of a specific flower with nectar in it, and made them more inclined to pollinate that flower.
Giving caffeine to bees may encourage bees to pollinate certain plants and help fruit growers increase yields, the experts think.
Bumblebees, in particular, are increasingly being used to pollinate soft fruit crops, such as strawberries, an economically important crop worldwide.
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A marked bumblebee visits a robot flower and a small sugar drop solution is given to the bumblebee as a reward
Previous studies have shown that bees love caffeine and are more likely to visit caffeinated flowers to get it.
But this is the first study to show that consuming caffeine in their nest helps bees find certain flowers outside the nest.
“If you give bees caffeine, they don’t do anything like flying in loops, but they seem to be more motivated and efficient,” said study author Dr Sarah Arnold of the Natural Resources Institute (NRI) at the University of Greenwich.
“We wanted to see if providing caffeine would help their brains create a positive association between a particular floral scent and a sugar reward.”
dr. Arnold, senior lecturer in insect behavior, worked with Jan-Hendrik Dudenhöffer, a postdoctoral researcher in Greenwich.
For the unique experiments, a total of 86 previously untrained bumblebees were divided into three groups.
Bumblebees can be found all over the garden collecting pollen and nectar from a variety of flowers and blossoms (stock image)
THE THREE GROUPS
1. Strawberry Fragrance and Caffeinated Sugar Solution
2. Strawberry Fragrance and Decaffeinated Sugar Solution
3. No Fragrance and Decaffeinated Sugar Solution
The first group was primed with the strawberry scent and a caffeinated sugar solution.
The second group of bees was given the strawberry scent and decaffeinated sugar solution, which allowed them to learn the positive association between the two, but without the caffeine boost.
The third group of bumblebees, meanwhile, was given a decaffeinated sugar solution without any associated odor.
Bees were then released into a flying arena, where they had to choose between two types of robotic flowers: strawberry-scented flowers or “distracting” flowers with a different, unknown scent.
The researchers hypothesized that if the bees hadn’t discovered a positive association between the scent of strawberry flowers and the nectar reward, they would visit the two types of flowers equally.
Coincidentally, 70.4 percent of the caffeinated bees (group one) were the first to visit the strawberry flowers — a percentage that the experts say is too high to explain by chance.
In comparison, 60 percent of the bees that were given the strawberry scent and sugar without caffeine (group two) initially opted for the strawberry flowers.
And 44.8 percent of the bees that received only caffeine-free sugar (group three) chose the strawberry flowers.
This difference suggests that caffeine had a noticeable impact on improving the insects’ ability to recognize a strawberry flower after it had had some of its scent in its nest.
Bumblebees in particular are increasingly used for pollinating soft fruit crops, such as strawberry – an economically important crop worldwide
Interestingly, this preference didn’t last long — researchers found that the caffeinated bees quickly overcame their early preference for strawberry flowers and began to visit the other type of flower almost as much.
“We should have expected this because the bees were fed sugar whether they visited the target flower or the distractor flower,” said Dr. Arnold.
“In some ways they unlearned as quickly as they learned.”
The researchers also noted that caffeine had a subtle effect on the bees’ “processing speed”—the number of flowers they visited in a given time.
All the bees got faster over time, but the bees that were fed caffeine improved the fastest, suggesting that caffeine may also improve motor learning skills.
Because fruit farmers spend a lot of money renting beehives to pollinate their crops, the study’s findings could have major implications for agriculture.
Strawberry growers buy hundreds of boxes of commercial bumblebees each year, but many of the bees may wander to neighboring wildflowers instead of the targeted strawberries.
With caffeine, farmers could better control which flowers they pollinate and increase yields.
The study was published today in Current Biology.
HOW TO PREVENT A HIBERNATING Bumblebee?
People often find hibernating bumblebees in late winter or early spring, when they start working in their gardens again.
The most common places to find them are in loose soil, banks of soil and occasionally in flower pots.
Overwintering bumblebees are all potential queens, hopefully making nests in the spring.
Exposing them may disturb them, and you may find them buzzing or vibrating.
If the bee is not too active, cover it again with the material that was hiding it.
Cover the bumblebee with the material as loosely as possible so she can dig her way out when it’s time to do so.
A bee that has survived hibernation can reproduce to produce a new colony.
As the summer progresses, the queen lays eggs that produce a new generation of queens and male bees.
The colony eventually leaves the nest and mates, with the young queens feasting on nectar and pollen to build up fat in their bodies.
In the end, the new queens only hibernate underground, with their vital fat reserves helping them get through the winter.
The rest of the nest — including the old queen, the male bees, and the female worker bees — falls away with the leaves and dies out in the fall.
Come spring, the warmer temperatures wake the queens from hibernation and they will seek nectar to feed on before finding a suitable nest site for the year – and the cycle continues.
Source: Bee Conservation Trust/Woodland Trust