It turns out humans aren’t the only ones getting a buzz from coffee.
Caffeine can improve memory among honeybees and lead to better plant pollination, according to a recent study published in the journal Science.
Researchers led by Geraldine Wright, a professor of neurobiology at Newcastle University in the UK, found that the nectar of citrus flowers, such as those of grapefruit and lemon plants, as well as coffee flowers that produce the ‘arabica’ species used for espresso and filter coffees contain low doses of caffeine. To entice bees to feed on these flowers, Wright and her team trained the insects to associate food with the smell of the flowers. They also trained another group of bees to feed on nectar from the flowers that was sweetened with a sugar, but not did not contain caffeine. After 24 hours, the bees trained on the caffeinated flowers returned to these these plants three times as often as those trained on the sweetened flowers returned to their uncaffeinated plants.
“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,” Wright said in a statement.
Such enhanced recall led to more effective pollination since once bees that consume the caffeine nectar, they continue to look for more coffee plants to pollinate, suggesting that the caffeine in the nectar played a role in improving the bees’ foraging abilities as well.
According to Wright, bees rely on their ability to learn and remember floral signals in order to find food. They use the information they gather about scents and colors associated with reward to seek out certain flowers and spread pollen from flower to flower within the same plant species. “This is good for the plant species because this kind of behavior in the pollinator means plants have more offspring. By enhancing their ability to remember the signals associated with a nectar reward using caffeine, the plant makes the bees even better at doing this task – and doing it for several days, even if other plant species offer flowers with food rewards,” says Wright.
(MORE: French Bees Produce Blue Honey)
Wright believes caffeine’s influence on the bee brain is similar to that on the neurons of the mammalian brain. “We used a technique of recording from bee brain neurons to measure how caffeine alters neural responses, and found that this change is similar to that produced by caffeine in neurons associated with learning and memory in the rat brain,” she says.
Figuring out ways to increase bees’ pollination habits have other implications too. Bee populations have been mysteriously declining, and while recent reports point to pesticides as the culprit, the dramatic drop in the insects’ numbers has serious consequences for ecosystems and and the farming industry, since bees help in the reproduction of crops and propagation of wild flower species. Understanding what keep bees buzzing could help to guide interventions that ensure the insects are able to remember and pollinate their favorite flowers.