Buzz kill: Unregulated spread of disease puts native bumble bees at risk

By now most of you have heard of Colony Collapse Disorder (CCD) – the mysterious condition that is causing the precipitous decline of honey bees.  In the US, these honey bees are not native and were brought here from Europe to help support the pollinating needs of our agricultural system.  They now play a vital role in producing our crops and their demise poses a serious threat to our food production. 

But what about the native pollinators such as the bumble bees of the US?  They too are important crop pollinators – particularly for crops that rely on the bumble bees’ “buzz pollination” technique such as tomatoes, peppers and cranberries.  While the honey bee has been historically favored over bumble bees for their agricultural pollination services, the decline of the honey bees has led to an increased demand for native pollinators.  Unfortunately, this demand has led to the commercial rearing and transporting of native bumble bees outside of their native range – a practice that has developed without regulations.  Now, native bumble bees are also facing declines likely due to the spread of disease from these commercially reared bumble bees.

In particular, two species of common bumble bees were shipped to Europe in the early 1990’s for commercial rearing where colonies were raised in the same facilities as European bumble bees and then returned to the US for use as pollinators.  According to Dr. Robin Thorp, a leading bumble bee expert, the US bumble bees may have been exposed to European pathogens for which they had no prior resistance.  Upon returning to the U.S., the common bumble bees are thought to have spread this disease to less common, wild populations of bumble bees that are now demonstrating declines.  Commercially reared bumble bees now harbor significantly more pathogens than wild ones and their escape from greenhouses in areas outside their native range leads to infections in nearby wild native species.

This is why NRDC joined with the Xerces Society and Defenders of Wildlife to submit a petition requesting that USDA regulate the movement of bumble bees throughout the United States and certify that bumble bees that are moved be free of diseases.  By monitoring the health and movement of our commercial, native bumble bees, we can better protect the important pollination services that they and their non-commercial counterparts provide.  While the mysterious die-off of the honey bee continues, this is an important, practical step we can take to protect our native pollinators from a similar fate.

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Photo of rusty patched bumble bee, © Johanna James-Heinz, used with permission