Funga-viral combination responsible for decline in bee population: US study

University researchers and military scientists in the US who jointly studied the population decline of bees in the US, have discovered that a combination of a virus and a fungus in the gut of honey bees may be responsible for a phenomenon called the colony-collapse disorder.

Beekeepers in the US, Europe and Asia, have, over the past four years, reported a huge decline in the population of the key insect that is critical to the pollination of many crops.

In the US alone 40 to 60 per cent of honeybee colonies have suffered a total collapse.

The difficult task of finding a cause for the problem becomes almost impossible as affected bees often fly off in different directions with the queen with only a few workers being left behind. Corpses of affected bees are therefore not easily available to carry out proper studies.

However, a team of researchers led by Jerry Bromenshenk of the University of Montana in Missoula investigating for unusual infections, after completing an exhaustive survey of bees backed by information bee keepers have collected from collapsed colonies, has found that the bees were infected with both a virus, called invertebrate iridescent virus (IIV) and a fungus known as Nosema apis. The university team worked with scientists at the US Army Edgewood Chemical Biological Centre in Maryland, who have developed expertise in detecting and analysing biological molecules.

"These findings implicate co-infection by IIV and Nosema with honey bee colony decline, giving credence to older research pointing to IIV, interacting with Nosema and mites, as probable cause of bee losses in the USA, Europe and Asia," the researchers write in their study published in the journal PLoSOne.