Washington: Researchers have found that honey bees are tuned in to the social culture of the hive as larvae, becoming more or less aggressive depending on who raises them.
University of Illinois entomology professor and Carl R Woese institute for genomic biology director Gene Robinson, who led the research with postdoctoral researcher Clare Rittschof and Pennsylvania state university professor Christina Grozinger studied very young bees that were weeks away from adulthood.
Robinson said "In a previous study, we cross-fostered adult bees from gentle colonies into more aggressive colonies and vice versa, and then we measured their brain gene expression. We found that the bees had a complex pattern of gene expression, partly influenced by their own personal genetic identity and partly influenced by the environment of the colony they were living in."
In the new study, the researchers again cross-fostered bees, but this time as larvae in order to manipulate the bees' early life experiences. The larvae were from a variety of queens, with sister larvae divided between high- and low-aggression colonies. The larvae were removed from their foster hives and put into a neutral laboratory environment one day before they emerged as adults.
Their aggressiveness by exposing them to an intruder bee are tested by researchers. Researchers found that the bees retained the social information they had acquired as larvae and those raised in aggressive colonies were 10 to 15% more aggressive than those raised in the gentler colonies.
Robinson also said "Even sisters born of the same queen but reared in different colonies differed in aggression, demonstrating the potency of this environmental effect. The finding was surprising in part because bee larvae undergo metamorphosis, which radically changes the structure of their bodies and brains. It's hard to imagine what elements of the brain are influenced during the larval period that then survive the massive reorganisation of the brain to bias behaviour in this way"
The team found that the aggressive honey bees also had more robust immune responses than their gentler counterparts, The researchers don't yet know how the social information is being transmitted to the larvae. They tested whether the bees differed in size, which would suggest that they had been fed differently, but found no size differences between aggressive and gentle bees.