Bees get a buzz from caffeine

A honey bee robs a comb. Photo by Lynn Ketchum

Scientists have today shown that caffeine improves a honeybee's memory and could help the plant recruit more bees to spread its pollen.

Publishing in Science the researchers show that in tests honeybees feeding on a sugar solution containing caffeine, which occurs naturally in the of and citrus flowers, were three times more likely to remember a flower's scent than those feeding on just sugar.

Study leader Dr Geraldine Wright, Reader in Neuroethology at Newcastle University, UK, explained that the effect of caffeine benefits both the honeybee and the plant: "Remembering floral traits is difficult for 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.

"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 .

"So, caffeine in nectar is likely to improve the bee's foraging prowess while providing the plant with a more faithful pollinator."

In the study, researchers found that the nectar of Citrus and Coffea species often contained low doses of caffeine. They included 'robusta' coffee species mainly used to produce freeze-dried coffee and 'arabica' used for espresso and filter coffee. Grapefruit, lemons, pomelo and oranges were also sampled and all contained caffeine.

Co-author Professor Phil Stevenson from the , Kew and the University of Greenwich's Natural Resources Institute, UK, said: "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 effect of caffeine on the bees' long-term memory was profound with three times as many bees remembering the floral scent 24 hours later and twice as many bees remembering the scent after three days.

Typically, the nectar in the flower of a coffee plant contains almost as much caffeine as a cup of instant coffee. Just as black coffee has a strong bitter taste to us, high concentrations of caffeine are repellent to honeybees.

Dr Wright added: "This work helps us understand the basic mechanisms of how caffeine affects our brains. What we see in bees could explain why people prefer to drink coffee when studying."

Dr Julie Mustard, a contributor to the study from Arizona State University, explains further: "Although human and honeybee brains obviously have lots of differences, when you look at the level of cells, proteins and genes, human and bee brains function very similarly. Thus, we can use the honeybee to investigate how affects our own brains and behaviours."

This project was funded in part by the Insect Pollinators Initiative which supports projects aimed at researching the causes and consequences of threats to insect pollinators and to inform the development of appropriate mitigation strategies.

Population declines among bees have serious consequences for natural ecosystems and agriculture since bees are essential pollinators for many crops and wild flowering species. If declines are allowed to continue there is a risk to our natural biodiversity and on some crop production.

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 's habits and preferences could help find ways to reinvigorate the species to protect our farming industry and countryside."

Explore further

Are bees also addicted to caffeine and nicotine?

More information: Caffeine in floral nectar enhances a pollinator's memory of reward. G.A. Wright, D.D. Baker, M.J.Palmer, J.A. Mustard, E. F. Power, A. M Borland, P.C. Stevenson. Science, 2013.
Journal information: Science

Citation: Bees get a buzz from caffeine (2013, March 7) retrieved 15 June 2019 from
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Mar 07, 2013

I wonder if various cultivars could be manipulated with genetic modification to produce alkaloids like caffeine in their blossoms to ensure better pollination.

Mar 07, 2013
The very last thing we need is genetically modified plants. It is as a result of mankind interfering with natural processes that we find the bes and other pollinators suffering from all manner of ailments. But it is not limited to pollinators. All sorts of species both plant and animal have come to grief because of our meddling.
Let's leave nature to decide what to modify. We don't need to meddle anymore than we have.

Mar 07, 2013
We've been eating " genetically modified " food since the 1930's.

How do you think we got most modern cultivars ?

By breeders playing with colchicine and inducing horizontal gene transfer.

People are too quick to jump at the mention of " genetic modification ".

Even if you shop " organic ", you are most likely eating " genetically modified " foods.

Mar 08, 2013

The difference is now you are eating corn with the BT toxin in it, and if Monsanto gets their way next, you'll be eating corn with an anti-herbicide gene in it as well.

There is no telling what this shit really does to the human digestive system and circulatory and nervous system over a human's entire life span, which probably won't be fully understood for like an entire generation from now.

BT corn kills butterflies, so what else does it kill?!

Everything else on Earth is immune to it? Hardly. It's probably a big factor in bee disappearances.

I haven't seen more than like one wild honey bee in several years. At one time, they used to come out to at least a garden or clovers, now you never even see them do that...

Mar 08, 2013
Oh yeah, we got a crate of these modified tomatoes a few months ago, and they were all discarded, because they have a woody texture. They are so woody in fact that they were dangerous to eat, and had hard splinters in their flesh. If you tried to swallow that you would choke on it, and probably need surgery to get the shit out of your throat.

Is that your idea of good food? Or more efficient or healthier food?

P.S. it's humorous that the bees themselves are also unnatural here, explaining why the native flora survives even without them, but what about our mostly European food crops?

Mar 08, 2013
Look, Herper, Bt doesn't work like that unless you happen to share the same protease found in an insect's stomach.

I was using different strains of Bt on organic farms before Monsanto started toying with it, I actually do know a little bit about it :)

It's a natural occurring soil bacteria.

The problem with combating any pest on crops, whether it be fungal, viral, insects, etc, with any remedy, is the sheer volume with which it's applied.

They tend to lose effectiveness rapidly, which is why you have to switch your methods to stay ahead of things from season to season, but as for it's ability to harm humans, it and it's derivatives were used successfully since the 1920's, with no harm done.

Mind you, I am not defending Monsanto's practices, I knew it was a bad idea back then solely from my experiences farming. Most farmers did, and we tried to get the word out, but for some reason nobody took us seriously.

Hate to rain some common sense on your bowl of doomflakes O:

Mar 08, 2013
The condition of your fruits and veggies has much more to do with the harvest window, the storage in controlled atmospheres in warehouses, the exposure to products off-gassed by other produce, and most importantly, the temperatures at which they are stored.

Grow a " flavor-saver " tomato from seed , yourself, and you'll find it's not much different then the run of the mill average mid-sized slicing tomato.

Pick it green and stick it in a refrigerated warehouse for a few months, with an atmosphere designed to prevent ripening, then force it to ripen by bombarding it with ethylene, wrap it in plastic and ship it halfway around the world, maybe irradiate it for good measure, and you'll end up with the common grocery store tomato.

Of course, I am only a 2nd generation chef with 20 years under my belt, I have no clue what I am talking about :)

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