Last Chance to Save Wild Bumble Bees -- Has Commercial Shipping Been Wiping Them Out?
In the early 1990s, the USDA conducted risk assessments of the interstate transport of bumble bees for commercial greenhouse pollination, particularly tomatoes. Because of the risk of introducing non-native pests and diseases into new areas, they concluded that commercially reared bumble bees should not be shipped beyond their native range (They also prohibited the importation of bumble bees from outside the country, with the exception of Canada). At the time, it seemed a simple solution to growing concerns that the fledgling industry had taken off before adequate regulatory measures were put in place.
There was already some concern that the genie had gotten out of the bottle. Between 1992 and 1994, queens of two North American species -- Bombus impatiens and Bombus occidentalis -- were sent to Europe where they were reared in facilities along side European bumble bees. The colonies were then shipped back to the United States and distributed for crop pollination.
Fast forward to 1997. The commercial bumble bee rearing industry in North America suffers such catastrophic losses of Bombus occidentalis, a western bumble bee that it wipes out nearly its entire stock. In the following years, scientists begin to observe the precipitous decline of several North American bumble bee species, all belonging to the same subgenus. Dr. Robbin Thorp, a bee researcher and Professor Emeritus at UC Davis, upon learning of the commercial declines wonders if there is some connection. Could the wild bees be dying of the same disease that swept through commercial facilities?
Thorp has come up with a thesis: that the recent decline of four North American bumble bee species is the result of a pathogen brought into the country by bees that were shipped to Europe. In short, he argues that the North American bees acquired a selectively virulent strain of Nosema bombi, a gut pathogen, while being reared alongside the European bumble bee Bombus terrestris. When the bees were sent back to the US and distributed, the pathogen made its way into the wild, decimating several closely related species.
This all ties back to the USDA's attempt to regulate the interstate shipment of bees because, in 1998, after commercial stocks of Bombus occidentalis were wiped out the industry was left with a single North American product: Bombus impatiens, an eastern bumble bee whose range extends from Maine to southern Florida. In 1998, USDA, against its own risk assessments, allowed the shipment of impatiens throughout the country. The largest greenhouse tomato-producing states -- Arizona, Texas, and Colorado -- are all states in which the bee is not native. It has been well documented that commercial bees can easily escape from greenhouses if necessary precautions are not taken.
In a story that I wrote for CounterPunch last fall, Wayne Wehling, senior entomologist at the USDA-APHIS, said that they still agreed with their earlier risk assessments.
"Certainly we have been all over the board with that," he told me. "And I think we've been all over the board largely because of the lack of clarity in the regulatory authority as to what our capacities really are."
To help clarify what the USDA Department of Animal Plant Health Inspection Service should be doing to protect our wild bees, the Xerces Society, a non-profit conservation group that focuses on protecting invertebrates, has filed a petition asking the USDA to regulate the interstate movement of bumble bees and to require that commercial breeders demonstrate that their bees are disease free. Along with the NRDC, Defenders of Wildlife, and Dr. Thorp, they write that, "The continued shipment of bumble bee pollinators to areas outside of their native ranges poses a grave threat to the wild populations of closely related bumble bee species. Without better regulation, we are likely to continue to see catastrophic declines, and possibly extinctions, of bumble bee pollinators."
APHIS is under no obligation to respond but Sarina Jepsen, Endangered Species Program Director at Xerces said in an email that, "Our hope is that pressure from various sectors (scientists, conservation orgs, sustainable agriculture groups, policy makers and others) coupled with this petition will encourage them to promulgate new regulations." According to USDA-APHIS, they are currently reviewing the petition to "determine our response." Perhaps when they do respond, they'll better clarify their regulatory authority.