By Nikk Ogasa
‘Gons. Gons. The queen is like that, ‘said one honey bee to the other. “Forward.”
Honeybees, of course, cannot speak, but scientists have found that the insects combine teamwork and scent chemicals to convey the queen’s location to the rest of the colony, revealing an extraordinary way of long-distance and mass communication.
The research is ‘very nice and very careful’, says Gordon Berman, a biologist at Emory University who was not involved in the study. This shows once again, he says, that insects can have ‘excellent and complicated behavior’.
Honeybees communicate with chemicals called pheromones, which they detect through their antennae. Like a king pushing a button, the queen sends out pheromones to summon worker bees to meet her needs. But her pheromones travel just as far. Busy worker bees wander around, however, and they too can call each other by releasing a pheromone called Nasanov, by a gesture known as’ fragrant; they lift their abdomen to expose their pheromone glands and wave their wings to guide the stinking chemicals backwards (seen in the video above and close-up in the video below).
Scientists have long known that individual bees are fragrant, but just how these individual signals work together to gather tens of thousands of bees around a queen, such as when the colony leaves the hive to swarm, has remained a mystery.
In the new study, Dieu My Nguyen, a computer scientist at the University of Colorado (CU), Boulder, and colleagues focus on a colony of western honeybees (Apis mellifera L.), the most common honey bee species in the world. The researchers set up a flat, pizza-sized arena with a transparent ceiling in which the bees could roam around but not fly. They put the queen bee in a cage on one side and let the workers release honey bees on the other side. The scientists record the movements of the insects from above with a camera; artificial intelligence software has detected bees releasing Nasanov pheromones.
Once the first worker honeybees tracked down the queen, they began to gather chains of bees at even distances that stretched from the queen outward, while each swung at Nasanov toward his neighbor. The findings, released this month in the Proceedings of the National Academy of Sciences, are the first direct observations of this collective communication in honeybees. Like stinking breadcrumbs, the branching lines of communication lead distant honeybees back to the queen’s place — an achievement no single bee could achieve alone.
“A really great analogy is the game of telephone,” says Orit Peleg, a computer scientist at CU and a senior author of the study. “You whisper a word in the ear of your neighbor, and they give it to their neighbor, and so on.”
The researchers shed some light on how honeybees recruit each other in these scent relays. They notice that bees in the relays are about 6 inches apart. According to Peleg, this indicates that the bees detect a certain amount of pheromones, drop what they are doing and contract to release their own pheromones.
Mark Carroll, an entomologist from the U.S. Department of Agriculture, warns that the work was done in a closed, virtually 2D space. In fact, he says, honey bee colonies are 3D, and they often have to contend with elements such as wind and rain, which complicate communication.
But by simplifying the problem, he says, this research provides insights into how swarming honey bee colonies can naturally organize. “The next step will be to observe natural honey bee swarms and see if they actually do.”