Study Shows Sick Bees Suffer Memory Problems
A new study from the University of Leicester revealed that bumblebees lose a bit of their buzz when ill, and have a tougher time doing daily tasks like remembering which flowers have the most nectar until they recover from illness.
Eamonn Mallon, an evolutionary biologist, said honeybees with activated immune systems also have memory problems.
He’s hoping that his findings will boost efforts to save the dwindling bee colonies throughout the world.
"This is an animal that lives on its memory," he said. "If even a minor infection hurts its memory that is a major cost."
Mallon said, like humans, bees can get sick and recover in days from infections after the immune system kicks into action to fight off viruses or parasites.
For the study, bees were divided into a control group and a group that were injected with lipopolysaccharide, a substance that stimulated an immune response without a need for the bee to be infected with a disease.
The bees were then offered the choice of blue and yellow artificial flowers only one type of which contained sugar water. An individual’s flight was recorded over ninety visits to these flowers.
Eventually all the bees spent their time feeding from the correct flower but it took the stimulated bees 10 percent longer to reach this point, showing that an active immune response when ill affects memory.
"This work has two important applications. Firstly, there is a lot of interest in the connections between the immune system and the nervous system in human biology,” said Mallon.
"Secondly, there is concern about both the decline in wild bumble-bee species and the effects of disease on the honeybee industry.”
He noted that learning is vitally important to how well a colony prospers. This effect of immunity on learning highlights a previously unconsidered effect of disease on colony success.
More than 25 native species of bumblebees are native to Britain, but three of those have been lost in the past 50 years and several are under threat.
Scientists say disease and farming methods that have deprived bumblebees of many traditional flowering plant food sources help explain the decline.
"This means we maybe have to take into account that disease is more important than we thought originally," Mallon said.
The research, ‘Immune response impairs learning in free flying bumble-bees’, was conducted in the Department of Biology, in collaboration with the Department of Genetics, at the University of Leicester.
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