Why Bees Leave Home

Scientists have found that foraging and food-gathering behaviours may be genetically encoded into the brains of honeybees. When honeybees leave a hive to begin foraging, there is an increase in an activity-boosting enzyme produced by the foraging gene, according to U of T zoology professor Marla Sokolowski and colleagues from the University of Bourgogne in France and the University of Illinois. This gene is the first one shown to affect division of labour in honeybee colonies, says the study, published in Science. Honeybees begin their adult life working inside the hive as nurses. After two to three weeks they change into foragers, taking longer flights away from the hive to collect pollen and nectar. During this time there are changes in their brain chemistry and structure, endocrine activity and gene expression. The researchers found that forager bees had significantly higher levels of expression of the foraging enzyme in their brains than nursing bees. “Foraging and other genes that affect similar behaviours might represent an important class of genes that are meaningful to our understanding of how genes influence behaviour,” says Sokolowski, who first discovered the foraging gene in fruit flies. The researchers theorize that changes in patterns of gene expression are important for driving behavioural change.