Possible Causes of Honeybee Colony Collapse Found

US scientists associated with the US Army and the University of Montana, have ascertained a possible cause for the annual decline in honeybee colonies in the USA.

To contextualize, the phenomenon is not unique to the United States and has been found to be affecting bee populations across the globe for a number of years.   In 2004, apiarists started to discover that large portions of their colonies were either dying or not returning to their hives.  Substantial losses year-over-year both in North America and Europe, have lead to a concerted global effort to ascertain the causative agents behind this situation.  Francis Ratnieks, a biologist at University of Sussex in Brighton, has stated in Wired magazine that there is no single rational at the global level, why bee populations are in decline.  He elaborates that honeybees are "probably dying for all kinds of different reasons from loss of their foraging grounds to increased exposure to global pathogens."  Pesticide usage, monoculture agricultural practices, urban sprawl, and climate change are also a few of the other causes that investigators have looked at to understand why bees are in decline.

The NY Times is reporting that American scientists, utilizing military research tools, have identified a fungus and virus pair that is present in 100% of all colony collapse cases evaluated in their labs.  Their findings suggest that "both the virus and the fungus proliferate in cool, damp weather, and both do their dirty work in the bee gut, suggesting that insect nutrition is somehow compromised."

The article reports on the host-parasite interaction:

“It’s chicken and egg in a sense — we don’t know which came first,” Dr. Bromenshenk said of the virus-fungus combo — nor is it clear, he added, whether one malady weakens the bees enough to be finished off by the second, or whether they somehow compound the other’s destructive power. “They’re co-factors, that’s all we can say at the moment,” he said. “They’re both present in all these collapsed colonies.”

The mechanisms that the fungus-virus pair is utilizing to undermining the bee populations is yet to be determined.

Still unsolved is what makes the bees fly off into the wild yonder at the point of death. One theory, Dr. Bromenshenk said, is that the viral-fungal combination disrupts memory or navigating skills and the bees simply get lost. Another possibility, he said, is a kind of insect insanity.

Further research into this phenomenon is necessary to understand a means of preventing future outbreaks.  However, we also know as in a case study in Britain where changes have been made to enhance the natural environment of bumblebees, such as "putting in pollen and nectar-rich flower margins to fields, growing red clover hay meadows and rotating the grazing of animals on land," that immediate improvements in the health of local bees could be achieved.