Scientists have discovered, honeybees sterilise their hives with antimicrobial resin. In doing so, they give the whole colony a form of “social immunity”.
Although honeybee resin is known to kill a range of pathogens, this is the first time that bees themselves have been shown to utilise its properties.
The team published details of their discovery in the journal Evolution.
Honeybees in the wild nest in tree cavities. When founding a new colony, they line the entire nest interior with a thin layer of resins that they mix with wax. This mixture is known as propolis. They also use propolis to smooth surfaces in the hive, close holes or cracks in the nest, reduce the size of the entrances to keep out intruders, and to embalm intruders that they’ve killed in the hive that are too big to remove.
Honeybees store propolis, which is a mixture of wax and resin, inside their hives. A number of studies have shown that propolis has a range of antimicrobial properties, but mostly in relation to human health.
Mike Simone, a PhD student from the University of Minnesota in St Paul, US, and his supervisor Professor Marla Spivak are doing research on propolis, they have already tested the effectiveness of honeybee propolis against the HIV-1 virus. Now they want to know what propolis is doing to the bees. for this experiment they took two hives, in one the walls were lined with the resin and other was without it. they created colonies of honeybees and housed them in each hive. After one week they collected the bees born in both the hives.
Genetic tests on these 7-day-old bees showed that those growing in the resin-rich colonies had less active immune systems. The resins likely inhibited bacterial growth. Therefore the bees did not have to activate their immune systems as much.
There is also some evidence that some mammals and birds coat themselves in naturally-occurring plant resin in a bid to reduce infestations with parasites.