Illustration by Bruce Morser/NGS
Honey bees famously do their waggle dance to tell others in their hive precisely where to find a good source of nectar or pollen.
Australian Scientists have demonstrated that when bees are given a low dose of cocaine they dance “extremely vigorously,” exaggerating the quality of the food source and behaving much like humans who consumed the highly addictive drug.
“Knowing that foraging honey bees are strongly motivated by rewards (dancing in response to the discovery of a rewarding nectar or pollen supply) and that this behavior is controlled by similar mechanisms to the ones that leave humans vulnerable to cocaine addiction, researchers wondered whether bees may be vulnerable to cocaine’s allure at the right dose,” says a news statement by The Journal of Experimental Biology.
Andrew Barron from Macquarie University, Australia, Gene Robinson from the University of Illinois at Urbana-Champaign, and Ryszard Maleszka at the Australian National University, publish the results of this investigation in the December 26 issue of the journal.
“Setting up his hives on a farm just outside Canberra, Barron trained the insects to visit a feeder stocked with a sugar solution. Then he gently applied a tiny drop of cocaine solution to the insect’s back, and waited to see how enthusiastically the foraging insects danced when returning to the hive,” the journal reported.
“Amazingly, low doses of the drug stimulated the insects to dance extremely vigorously. They behaved as if the sucrose solution was of a much higher quality than it really was.”
Photo of honey bees by Bianca Lavies/NGS
The cocaine seemed to be hitting the insects’ reward centers, but were they really responding to the drug like humans or was the drug stimulating some other aspect of the insects’ behavior to look as if they were becoming addicted?
Testing the bees’ sensitivity to sugar solutions, the drugged bees responded more strongly than bees that had not been drugged, so cocaine was increasing their sugar sensitivity, the scientists deduced.
But was it only increasing their sensitivity to sugar, or increasing their response to all rewards?
Barron offered the drugged insects pollen to see if cocaine increased their sensitivity to other floral rewards and found that the foragers were equally overenthusiastic, dancing as if the pollen quality was much better than it really was, the journal said.
The researchers also wondered whether bees that had been on cocaine for a few days had become dependent and went into withdrawal when the drug was withheld. Testing showed they did, just like humans going into withdrawal.
“Barron is confident that honeybees are as susceptible to cocaine’s allure as humans, and is keen to find out more about the drug’s effects,” says the release.
“He hopes to identify the neural pathways that it targets to find out more about the mechanisms involved in human addiction and to find out whether the drug has as devastating an effect on honey bee society as it does on human society.”
Watch a video of the bee waggle dance, as it aired in the Nature documentary “Silence of the Bees” on PBS. This is not related to the cocaine research.