Modern supermarkets offer a rainbow of fruits and veggies. Bees are responsible for peppers, avocadoes and strawberries as well as cucumbers. Sarah Arnold, an ecologist at the University of Greenwich, said that there are not enough pollinators in nature to support our global crop loads. Farmers release thousands of commercially raised bees onto their fields. The insects work tirelessly to pollinate billions worth of crops each year. Their fuzzy bodies collect powdery pollen from flowers as they go, so when they visit another flower, the powdery pollen is spread.Commercial bees can sometimes wander off to look at wildflowers in nearby fields. Scientists have discovered that bees can benefit from a quick boost of caffeine, just like humans. This helps them stay focused and gets the job done faster. Arnold and her collaborators found that bumblebees respond to caffeine by smelling a specific floral scent when they leave the nest. The bees that are caffeinated visit target-scented flowers faster than those who don't get the extra boost. These findings could be used to help industrial agriculture train bees to be more productive, the team reported Wednesday in Current Biology.Jessamyn Mannson, an ecologist from the University of Virginia, said that pollinators have been proven to be able to identify which flowers to visit through scents in the nest. Arnold points out that previous research had indicated that bees prefer artificial flowers that contain caffeine. However, it was not clear how caffeine might affect bees' actions. Another study found that honeybees tethered to caffeine and exposed to a scent for longer periods of exposure to it stick out their tongues. However, they were not able to choose which flowers they wanted to visit.Arnold and her team created three groups of bumblebees to investigate further. One received caffeinated sugar water with a blast strawberry-flower smell. One received the odor and plain sugar water, while another got the sugar water alone. None of the bees had ever encountered floral or flower scents before. Each group was taken out of its hive and placed in a laboratory with artificial flowers. Some released the same strawberry scent while others released a different distractor floral smell. The fake flowers had reservoirs of sugar water, which was without caffeine, for the bees.The faux strawberry blossoms were a favorite of the caffeinated bees, with 70.4 visiting them right away. The noncaffeinated, but odor-primed bees visited the fake strawberry blossoms only 60% of the time. This is expected because they hadn't learned how to choose the right plants.Arnold states that bees that were exposed to both caffeine as well as odor developed a strong association. This could be a sign that their motor skills might be enhanced by caffeine.Although the positive association was strong it eventually faded. After seeing dozens of flowers, the caffeinated honey bees began to investigate the distractor flowers. Arnold points out the laboratory setup as the cause. It is quite easy for bees find plastic flowers that are only a few inches from one another. The bees will eventually try the distractor flowers, but in a field full of strawberries, real distractors might be farther away. It may take them longer to abandon their task. Arnold suggests that in an agricultural setting, the bees could receive caffeine along with priming scents to specific plants in commercially-produced hives. For bees to work more efficiently, farmers could place caffeinated honey hives in their fields.Manson suggests that this strategy may be more effective for farms in the United Kingdom than it is for farms in the United States. U.K. farms are smaller and easier to escape from for pollinators if they are not trained. She adds that U.S. crops are often pollinated by bees in large fields that are difficult to escape from or in greenhouses that bees can't escape.Manson believes these new results could have a wide range of industrial applications. She says that humans actively seek caffeine and that pollinators also do. It's delicious and amazing. However, because the caffeine was given to the bees in the nest, rather than as a reward at a flower, it is an excellent demonstration of how caffeine can be used to teach them which plants they should pollinate.
