Is Commercial Bumblebee Raising Wiping Out Our Native Bees? - Page 2

Karl Valley, chief of the division of entomology at the Pennsylvania Department of Agriculture at the time (and currently chief of the division of plant protection), says that the inspection involved removing a single bee from each package, placing it in alcohol, and examining the exterior portions of the body for mites. They did not look for pathogens or other diseases specific to bumblebees. He doesn't recall how many shipments they received, where the bees were sent after they were examined, or if records from that period still exist.

Additional specimens were also sent to the Bee Laboratory in Beltsville, MD. According to a permit issued in 1992 and obtained by Dr. Thorp through a Freedom Of Information Act request, some of the bees were quarantined at the Maryland facility. "When cleared," the document states, "Dr. Shumanuki [sic] will release the bees to you and notify this office."

Dr. Hachiro Shimanuki was the research leader at the Beltsville Lab at the time and now lives in Florida. He recalls having examined only one sample of bumblebees from Europe over a three-year period and says that the company provided the sample.

"We certainly couldn't tell you whether it was a one percent sample or a one-thousandth of a percent sample," he told me. "It was just something that they sent to us as being typical of the kind of shipment they would like to make."

"There was really no request to look for any particular disease," Shimanuki adds. "As I recall, I think all it was was: Would the importation endanger our honeybees? That was really the question I guess that we tried to resolve in some way. That was our concern. But other than that, we didn't know what to look for."

There's another note on the permit record. It states that Dr. De Jonghe, a veterinarian and founder of Biobest, is the largest producer of bumblebees in the world and that the bees are "certified to be free of pathogens."

Leamington, Ontario (the "Tomato Capital of Canada") until recently had the highest concentration of commercial greenhouses in all of North America. (That honor now goes to Mexico, where Koppert has had a rearing facility since 2004 and produces B. impatiens, a bee that is not native to Mexico or the West Coast, for crop pollination.) The number of bumblebees needed for greenhouse pollination can reach into the tens of thousands. Houweling Nurseries in southern California, with 124 acres under glass, introduces roughly 20 hives with between 50 and 70 bees twice a week. That comes close to 30,000 bees a year.

Although Houweling installed insect screens on all of its vent windows in 2000 (to keep other insects out, not to prevent bees from escaping), they are not required by law and, without them, worker bees can easily escape, forage for pollen in the wild, and then return to the greenhouse. (According to Kueneman, during the early years of the industry, less than half of all greenhouses were using insect screens.) Hives sent to the West Coast, far outside the native range of B. impatiens, must be equipped with queen excluders -- a very narrow rectangular opening large enough only for workers to get out. When the growers are through with the hives, they are required by law to destroy them either by drowning the bees or freezing them overnight.

Michael Otterstatter has studied the interaction between wild bees and pathogens for more than two decades and, five years ago, with a team of scientists from the University of Toronto, decided to look at whether commercial bees had higher rates of disease and if those diseases were spilling into wild populations. Otterstatter conducted a straightforward study that compared the prevalence of four pathogens among bees foraging in close proximity to commercial greenhouses with bees foraging in areas where there were no greenhouses. They sampled from six sites in southwestern Ontario, including Leamington, and found that bees near commercial greenhouses had a much higher rate of disease than those collected elsewhere. In fact, the presence of Crithidia bombi, a gut pathogen that lives within the intestinal tract of bumblebees (like Nosema bombi) and can spread between bees at flowers, was found only in bees foraging near greenhouses.

"It actually turns out to be present in almost 90% of the [commercial] colonies we looked at," Otterstatter says. "Nearly all of them. And the other place that you find this pathogen is in populations of bees right around greenhouses, within a few kilometers...It really looked like a disease that you only find around greenhouses."

Otterstatter's research team also found that the prevalence of N. bombi was three times higher at the Leamington site than elsewhere and that the infections tended to be more intense. Otterstatter notes that every study of commercially reared bees conducted in North America, Europe, and elsewhere has revealed very high levels of parasitic organisms, many of which are rare or entirely absent from most wild populations.

The commercial bumblebee industry is relatively young. As greenhouse production has expanded, so has the need for pollinators.

Koppert's Ruiter points out that his company's bees were not used in Otterstatter's study and says that the unusually high rate of disease is not a reflection of the industry at large. "It's appalling that something like that happens," he says. "I'm embarrassed for my industry. On the other hand, when I called him about his study, he was forthright in admitting that he didn't use our material, which is a good sign for us that we are doing what we're supposed to be doing, which is keeping things disease free."

According to Ruiter, Koppert's bees are inspected every two weeks by the Michigan Department of Agriculture and annually by Michigan State University. Ward, of Biobest, says that their facility is inspected on a regular basis without warning and that every shipment of bees made to the U.S. or Mexico must have a health certificate signed by the Canadian Food Inspection Agency (CFIA).

The rise of the commercial bumblebee industry reveals the limits of APHIS's regulatory authority. Prior to 1997, when Koppert's bees were infected with N. bombi, there was a gentleman's agreement that B. occidentalis would be used only in the western United States and B. impatiens in the east, roughly within their natural ranges. In 1994, when the importation of bees from Europe was discontinued, Secretary of Agriculture Mike Espy spelled out the agency's policy in a letter addressing concerns raised by Congressman Sam Farr (D-CA). "Risk assessments conducted by APHIS officials indicate that this type of movement could result in the introduction of bumblebee pests and diseases into new areas, such as eastern species of parasitic nematodes into Western States," he wrote. Therefore APHIS would not be issuing permits for the movement of eastern species west of the 100th meridian and vice versa.

But now that B. occidentalis has been removed from the market, B. impatiens is shipped freely to western states. When I asked Wayne Wehling, senior entomologist at the USDA, if APHIS still agreed with its earlier risk assessments he said, "Well, yes. That's the simple answer.

"Certainly we have been all over the board with that," he acknowledged. "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."

Although the same concerns apply today, there are few restrictions (other than the use of queen excluders) on the interstate shipment of B. impatiens in the U.S. The largest greenhouse tomato-producing states -- Arizona, Texas, and Colorado -- are all states in which the bee is not native, and while the companies are happy to abide by the law, they do not share the concern about the shipment of bees outside of their native ranges.

For conservationists and many scientists, the movement of an eastern species to the West is reckless. If a queen did somehow escape and the bee became naturalized, it could compete with local species for floral resources, and close relatives of B. impatiens would be susceptible to nonnative diseases. "The diseases that are in B. impatiens could be virulent in things out here. We just don't know and I don't think we want to risk trying," Thorp says.

Globally, the issues and potential problems are perhaps even more pressing. B. terrestris has been introduced to Japan and Chile, where it is not native, and has become naturalized. Two parasites previously unknown in Japan, including N. bombi, have entered the country along with the commercial bumblebees. There are reports that B. terrestris has migrated from Chile into Argentina and that the bee may have been spotted in Uruguay as well. It is only in the last few years that the importation of B. terrestris into Mexico has been stopped. According to Wehling, the bee has already established itself in areas surrounding greenhouse production in the state of Michoacan, west of Mexico City.

In Canada, a laissez-faire approach rules. The greenhouse industry in southwestern British Columbia relies heavily on commercial bumblebees and, although queen excluders must be present on all hives shipped west of the 100th meridian, most greenhouses do not have screens covering the vents, so worker bees would have no trouble escaping. Given the urgency of a memo from Agriculture Canada's Central Plant Health Laboratory to APHIS in 1993, this is even more surprising:

"We really must get together to discuss a plan of action," it reads. "It appears that attempts to limit the movement of Bombus is not working. Bombus impatiens is being moved into California. Perhaps there is a need to review the whole policy of Bombus importations into North America before all hell breaks loose."

The battle over the bees echoes other controversies that have erupted around domestication of previously wild species. One example cited frequently in the literature on bumblebees is the spread of sea lice among farmed salmon in the Pacific Northwest, which led to the decimation of wild populations. Many fishermen, conservationists, and activists warned early on that the proliferation of disease among farmed, nonnative Atlantic salmon could spread to wild fish. They were largely ignored and told that no evidence had been found to prove such a hypothesis and that in fact the pathogens had migrated from wild salmon to farm stock.

Large fish die-offs were observed as early as 1989. In 2001, an outbreak of sea lice in Broughton, British Columbia led to one of the most dramatic declines of wild salmon ever seen. In a single generation, local pink salmon runs fell from 3.6 million spawners to 147,000.

Bumblebees, of course, are not salmon, but some of the same principles apply. "Feedlot farming attempts to break immutable laws of nature by overcrowding animals, lowering their genetic diversity and putting them where they do not belong," wrote Alexandra Morton in an essay on salmon farming published in 2004. The titles of many such essays and books are becoming all too familiar: "Silent Spring of the Sea," Fruitless Fall, etc. In the case of bumblebees, there is a wealth of evidence pointing to the risks associated with the importation of nonnative species and of pathogen spillover. Yet, according to Otterstatter, Thorp, and others, the regulations in place are hardly adequate to ensure that risks are minimized. Discontinuing the shipment of bees beyond their native ranges and requiring all greenhouses to install insect screens would be a start, they say.

"Bumblebees are marvelous pollinators and I really wouldn't want to see the industry come to a halt," Thorp says. "But I would like to see a lot more protection of the potential environmental risk."

This article is by Adam Federman, and originally appeared in Earth Island Journal. It is reprinted with permission. Federman is a contributing writer to Earth Island Journal. His last article for the magazine was on illegal logging in Siberia.

Also from Earth Island Journal:
Rumble in the Jungle: Timber or Tourists? Environmentalists are Fighting Each Other Over How Best to Protect Forests in Guatemala
Hacking the Sky: Geo-Engineering Could Save the Planet...And in the Process Sacrifice the World
Global Warming Warrior Dr. James Hansen

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