Plants give honeybees a boost of caffeine so insects return to pollinate Bees get caffeine from some plant's nectar and this boosts their memory Encourages them to return to the species increasing its pollination chance Honeybees get a shot of caffeine from certain flowers toperk up their memory, a new study has found. This caffeine burst encourages the bees to return to the same type of plant, boosting its chances of pollination. One of the flowers that gives bees a caffeine hit is the coffee plant. Honeybees get a shot of caffeine from certain flowers and it perks up their memory Its nectar offers as much caffeine as a cup of instant coffee, according to researchers at Newcastle University. However, some citrus plants contain caffeine as well, albeit in lower concentrations - it is found in the nectar of orange and grapefruit blossoms. The caffeine helps a bee remember that the flower's scent promises a tasty payoff, the researchers said. So the bee will seek out those flowers, transferring their pollen. Dr Geraldine Wright, who led the study, said: "Remembering floral traits is difficult for bees as they fly from flower to flower so fast. We have found that caffeine helps the bee remember where the flowers are. In turn, bees that have fed on caffeine-laced nectar are laden with coffee pollen and these bees search for other coffee plants to find more nectar, leading to better pollination. So, caffeine in nectar is likely to improve the bee's foraging prowess while providing the plant with a more faithful pollinator. The caffeine burst encourages the bees to return to the same type of plant, boosting its chances of pollination Co-author, Professor Phil Stevenson, from the Royal Botanic Gardens at Kew, and the University of Greenwich's Natural Resources Institute, added: "Caffeine is a defence chemical in plants and tastes bitter to many insects including bees so we were surprised to find it in the nectar. However, it occurs at a dose that's too low for the bees to taste but high enough to affect bee behaviour. The researchers trained bees to expect a sugary drink when they smelled certain flowers. Some of the bees were given caffeine in their drink, while others were not. The same bees were later exposed to the scent again. The scientists watched whether the bees extended their feeding tubes in response. After 24 hours the bees given caffeine were three times more likely to extend their feeding tubes than those that were not After 72 hours the bees that were given caffeine were twice as likely to remember the scent. The researchers made the discovery by carrying out an experiment that used lab tools instead of flowers. They trained individual bees to expect a sugary drink when they smelled a certain floral scent. Some bees got caffeine in their drink while others did not. Later they exposed the insects to the same scent and watched to see if they extended their feeding tubes in response, a sign they were ready to sip. After 24 hours, the bees that had been given caffeine were three times as likely to remember as bees that had not. After 72 hours they were twice as likely to remember. Bees cannot taste caffeine at levels found in nectar, but the researchers found it affects certain brain cells involved in memory. Professor Stevenson said: "Understanding how bees choose to forage and return to some flowers over others will help inform how landscapes could be better managed. Understanding a honeybee's habits and preferences could help find ways to reinvigorate the species to protect our farming industry and countryside.