Honeybees Avoid Giant Wasps: Predators Drive Bees Away from Food Sources

Honeybees rely on nectar to make the sweet honey that can be found in homes across the United States. Yet these bees live in constant danger as predators wait to seize them out of the skies or ambush them on flowers. Now, researchers have discovered that these predators can drive bees to avoid nectar and food sources. The findings are more important than ever as honeybees continue to decline across the country.

In order to examine honeybee behavior, the researchers studied the impact of the monstrous-looking Asian Giant hornet and a smaller hornet species called Vespa tropica on the foraging behavior of Asian honeybees.  Both of these hornets pose dangers to honeybees and the smaller one has actually invaded Europe, threatening the bees there.

In order to examine the behavior of these bees, the researchers presented the insects with different combinations of safe and dangerous feeders containing varying concentrations of sucrose. This allowed them to see which feeders the bees avoided and which they naturally flocked to.

"Bees avoided the dangerous feeders and preferred feeders that provided sweeter nectar," said James Nieh, one of the researchers, in a news release. "However, predators 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 bees were more risk-tolerant. They avoided the giant hornet at the bets food, but continued to visit the lower quality food with the smaller hornet."

It turns out that the bees treated the bigger hornet species, which is four times more massive than the smaller species, as the more dangerous threat.

"The Asian Giant hornets are dangerous, heavily armored predators," said Ken Tan, one of the researchers, in a news release. "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 findings reveal a little bit more about this bee behavior. In particular, it shows that the strategy of colonies is different from that of individual forages. This behavior could allow the honeybees to exploit all of the available food sources, which is more important than ever as these insects continue to disappear across the globe.

The findings are published in the journal PLOS One.