The Multitasking Bumblebee - Multitasking Week

ADDITIONAL CONTRIBUTORS Tanya Silverman

By Tanya Silverman

Image courtesy of Cebix.net.

Think you’re so savvy because you proudly put “multitasking” under the “Professional Skills” list on your polished resume? Sure, you can briefly place a conference call on hold while you balance these spreadsheets and file those invoices, but can you effectively collect a rewarding harvest while avoiding camouflaged predators that could easily kill you?

Unless you’re a professional bumblebee, you probably said no.

“We have really strong interest in how bees behave,” scientist Thomas Ings tells BTR.

Speaking on behalf of his research team – which includes Mu-Yan Wang, Michael Proulx, and Lars Chittka – Ings explains their specific interests, such as “how bees respond to the presence of predators that were able to camouflage themselves,” likewise, their ability to discriminate what is the “most rewarding flower” when they buzz around through “hundreds, even thousands, of flowers per day.”

They took their bee behavior queries to the lab.

“The first thing we needed to do was to set up an artificial meadow,” Ings tells BTR. They did so by arranging an array of fake yellow flowers, half of which were light, and half dark. Filling syringes with sugar water, they injected a designated volume to make the darker ones sweeter (thereby more rewarding) and the lighter ones more diluted.

To install the predatory aspect, a quarter of the sweet flowers also hosted a robotic spider, some of which were “highly conspicuous,” where they easily stood out, while others were more cryptic, “for instance, a dark yellow spider on a dark yellow flower,” to mimic camouflaged spiders in nature. When the insects would land on the spider-hosting flowers, the researchers would trigger the robotic predators to attack. Ings says these attacks do not actually injure these bees, but are merely a means to make them rapidly detect danger zones.

“That was a fairly easy experiment and shows some very interesting results that bees, when [recognizing] conspicuous spiders, continue to forage on the highly rewarding flowers and just avoided the spiders on those particular flowers,” he says.

On the other hand, when dealing with camouflaged spiders’ attacks, it caused bees to avoid those particular flowers. Given the danger evasion aspect, the researchers also noticed that when the bees continued harvesting through the rest of the field, they did not discriminate between flowers so clearly, foraging from all the rewarding and unrewarding ones at random.

“So this made us wonder, is it because bees can’t multitask? Or, perhaps, is the site that we use not sufficiently demanding to force bees to do so?”

Back to the artificial meadow board, Ings and his teammates set up the second stage, but this time injected sugar in the light flowers, and a bitter solution in the darker ones. Some of the sweeter flowers were again set up with camouflaged spiders that would attack.

Examining the bumblebees buzz through this setting, Ings says his team “did find that bees were able to avoid the spiders, but at the same time, they could still select” the sweeter flowers “and avoid the bitter ones.”

Ultimately, the researchers determined that bumblebees can, in fact, multitask but will only do so “when they’ve [been] given sufficient incentive,” i.e. dealing with dodging undesired tastes and lethal predators.

No matter what your social species, multitasking is difficult – whether you’re an ambitious human being trying to climb the corporate ladder or an anonymous member of an insect colony who’s quite low on the food chain.

As for future experiments, Thomas Ings, who studies all sorts of bee matters, is also interested in quantifying the cost and benefits on bumblebees’ multitasking efforts, for instance, determining how much energy the bee exerts on such behavior. Another potential prospect is to make these experiments less sheltered by transitioning “really nice and controlled lab experiments out into more complex field environments.”

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