Sick bees lose their buzz, study finds

LONDON (Reuters) - Bumblebees lose a bit of their buzz when ill, and like humans, have a tougher time doing daily tasks until they recover, British researchers said on Wednesday.

Honeybees with activated immune systems also have memory problems, according to evolutionary biologist Eamonn Mallon of the University of Leicester, who said his findings can boost efforts to save dwindling bee colonies.

"This is an animal that lives on its memory," he said. "If even a minor infection hurts its memory that is a major cost."

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, Mallon said. The team reported its findings in the Royal Society's journal, Biology Letters.

The researchers divided bees into two groups and injected half with a substance that stimulated the immune system. They then offered the bees the choice of blue and yellow flowers but only one color contained sugar water.

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, the researchers said.

Britain once had more than 25 native species of bumblebee, 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," he said in a telephone interview. "There is concern about both the decline in wild bumblebee species and the effects of disease on the honeybee industry.

(Reporting by Michael Kahn; Editing by Douglas Hamilton)