Australasian Science: Australia's authority on science since 1938

Bees Have Lateralised Brains Too

Lateralisation has been considered a unique characteristic of the human brain, with different types of processing taking place in the left and right hemispheres. Australian research has now concluded that the social demands imposed on honeybees has seen lateralisation evolve in their brains too.

E/Prof Lesley Rogers of The University of New England compared brain structure in the social honeybee as well as the solitary mason bee. “In social bees, for example, each antenna has a different function in feeding and in social behaviour,” Rogers explains. “Honeybees use their right antenna to recall short-term memories of particular odours associated with a reward of sugar. The left antenna allows them to recall only long-term memories.”

During social interactions between pairs of honeybees, the researchers found that hive mates recognised each other when the bees used their right antennae but not when they used their left. “The use of the left antennae leads to aggression between members of the same hive. So we therefore hypothesised that lateralisation of brain function in the same direction for most members of a species may have evolved only in social species.”

The researchers then looked at the mason bee, which has limited social interaction. When feeding, which they do alone, mason bees do not show the population lateralisation characteristic of social bees.

“We decided to test social interactions in pairs of mason bees,” Rogers says. “In pairs of males or females with only their left antennae in use, aggressive behaviour was elevated, and more so in females than males. Pairs using their right antennae, or both antennae, did not have any elevated aggression. Hence, lateralisation in the same direction in all or most members of a species is present for social behaviour but not for behaviour which is performed alone.”

The study was published in Nature (http://tinyurl.com/guraudd).