Fear of predators drives honey bees away from good food sources

Oct 02, 2013
The smaller hornet studied by the researchers attacks a honeybee forager on a flower. Credit: Ken Tan

Most of us think of honey bees as having a bucolic, pastoral existence—flying from flower to flower to collect the nectar they then turn into honey. But while they're capable of defending themselves with their painful stings, honey bees live in a world filled with danger in which predators seize them from the sky and wait to ambush them on flowers.

Such fear drives bees to avoid closely associated with predators and, interestingly, makes colonies of bees less risk-tolerant than individual bees, according to a study published in this week's issue of the open-access journal PLOS ONE.

"This strategy of colonies collectively exhibiting significantly more caution than the riskier individual foragers may help honey bees exploit all of the available food sources, with some intrepid foragers visiting more dangerous food while the colony judiciously decides how to best allocate its foraging," says James Nieh, a professor of biology at UC San Diego.

Nieh worked with scientists at Yunnan Agricultural University in China to study the impact on foraging Asian honey bees of the monstrous-looking Asian Giant hornet, Vespa tropica, and a smaller hornet species known as Vespa velutina, which has invaded Europe and now poses a threat to European honey bees.

"The Asian Giant hornets are dangerous, heavily armored predators," says Ken Tan, the first author of the paper, who also works at the Chinese Academy of Science's Xishuangbanna Tropical Botanical Garden. "Bee colonies respond by forming balls of defending bees, encasing the hornet and, in some cases, cooking it to death with heat generated by the bees."

The researchers found that bees treated the bigger hornet species, which is four times more massive than the smaller species, as more dangerous. In a series of experiments, they presented bees with different combinations of safe and dangerous feeders—depending on their association with the larger or smaller hornets—containing varying concentrations of sucrose.

"Bees avoided the dangerous feeders and preferred feeders that provided sweeter nectar," says Nieh. "However, are clever and can focus on sweeter food, ones which bees prefer. So we also tested how bees would respond when sweeter food was also more dangerous. What we found was that the individual were more risk-tolerant. They avoided the giant hornet at the best food, but continued to visit the lower quality food with the smaller ."

Explore further: Rare Sri Lankan leopards born in French zoo

More information: dx.plos.org/10.1371/journal.pone.0075841

Related Stories

How do bees make honey? It's not just bee barf

Jun 20, 2013

(Phys.org) —Last weekend, my daughter asked me how bees made honey, and I realized that I didn't know the answer. How do bees make honey? I did some homework, and can now explain it to her – and to you.

Recommended for you

'Killer sperm' prevents mating between worm species

17 hours ago

The classic definition of a biological species is the ability to breed within its group, and the inability to breed outside it. For instance, breeding a horse and a donkey may result in a live mule offspring, ...

Rare Sri Lankan leopards born in French zoo

20 hours ago

Two rare Sri Lankan leopard cubs have been born in a zoo in northern France, a boost for a sub-species that numbers only about 700 in the wild, the head of the facility said Tuesday.

Researcher reveals how amphibians crossed continents

22 hours ago

There are more than 7,000 known species of amphibians that can be found in nearly every type of ecosystem on six continents. But there have been few attempts to understand exactly when and how frogs, toads, ...

User comments : 0