Wild bees are vanishing, so what can we do?

In the UK, fruit growers have turned to commercially bought bumble bees, because they are great pollinators.

The problem is, bumble bees can be lazy and will hang around the nest all day.

And when motivated to get out and about, they’ll often become distracted by native wildflowers, and ignore the crop flowers they’re meant to be pollinating.

It’s like they have an insect version of attention deficit disorder. Can they be sorted out with a pill?

Coffee and bees: An unlikely love story

Previous research found that honey bees fed on caffeine formed “longer-lasting memories of odours associated with good food”.

This seemed to put a pollination map in their little heads – because they were better at recalling “flying routes and the best sources of nectar” .

They knew where to find the good stuff.

In a new experiment, researchers from the Natural Resources Institute (NRI) at the University of Greenwich wanted to see if slacker bumble bees could be similarly trained and motivated to target specific flowers, and pollinate them more effectively and reliably.

To this end, the scientists mixed up caffeine, sugar and perfume smelling like strawberries – a crop that bumble bees do a good job pollinating, when they’re in the mood.

But because this was a controlled laboratory experiment, the strawberry plants were actually robot flowers.

So what happened next?

The caffeine, sugar and perfume were wafted through the nest before the bees were in the laboratory, where the robotic flowers awaited them.

Half of the flowers had the synthesised odour of strawberry flowers – and the other half had an odour called linalool, a common flower scent that is not present in strawberries.

There was a control group of bees that missed out on the coffee-sugar hit.

What a buzz! The experiment worked

Dr Sarah Arnold, the NRI researcher who led the project, said in a prepared statement: “In our laboratory experiment, we found that the bees we had trained using the caffeine/sugar/odour priming treatment were much more interested in the target flowers with the strawberry odour, compared to the distractor flowers.”

Dr Arnold said the caffeine-odour priming method on crops “could boost fruit yields because the bees are more focused on visiting and pollinating the crop flowers”.

She said this technique could be used to “help guide that behaviour and enhance their performance in the field, by giving them a little bit of priming or pre-training within the nest”.

She said the experiment “gives us insights into how bees think and learn, so it tells us a bit about how caffeine works in their brains”.

Dr Arnold said it’s like a person drinking coffee while revising for an exam.

We generally know how coffee helps us concentrate and stay focused, as well as helping us remember complex information better, and what our limit is.

“We’ve shown that caffeine increases the bees’ enthusiasm and activity generally and it makes the memory formation stronger,” Dr Arnold said.

“The bees that did have caffeine showed more interest in the target odour flowers compared to the ones that did not.”

There are no native bumble bees in Australia. There is, however, an invasive species that pollinates weeds. So best not give them coffee.