A new study shows that certain plants are able to tailor the chemistry of their nectar to increase their attractiveness to honeybees. Plants have a wealth of chemical weapons at their disposal. The arsenal is usually used to fight off hungry insects but new research shows that they can also use chemistry to attract pollinators like the busy bee. In this case, caffeine is the chemical of choice. Caffeine was detected in the nectar from several varieties of Coffea and Citrus. These plants are also known to produce more fruit and seeds when pollinated by bees rather than another pollinator.
The scientists were able to train the bees (I’m imagining a bee bootcamp) to respond to a cue using a reward system. The bees were rewarded with sugar syrup or sugar syrup and caffeine. They found that the bees responded better to the caffeinated syrup, that they preferred it. Even better, the bees memory of where the caffeine was got better with time. The caffeine dose had improved their memory.
The weird thing is, bees don’t even like the taste of caffeine! In high doses, it repels the bees, higher still it would kill them. So the plants are able to tailor the mixture just so, to give the bees a nice buzz but not to drive them away, or worse… What do the plants gain from this? Bee loyalty of course. Making the bees more likely to visit that plant variety over another and improving its chance of survival. As for us, we know that caffeine in low doses is good for a boost but it also improves memory too. I’m off for a brew.
Reference: Wright et al., Science. 339. 1202. 2013.
Photo courtesy of Katy Jenkins (The Glynhir Estate)