Plight of the Bumblebee
Bees, and particularly the European honeybee, Apis mellifera,
have come to symbolize a deepening ecological crisis in North America.
Colony Collapse Disorder, first reported in 2006, has been described as
"an insect version of AIDS,"
ravaging honeybee colonies throughout North America. It has become a
cause célèbre of sorts, embraced by Häagen-Dazs, which features the bee
on some of its pints of ice cream and asks consumers to imagine a world
without pears, raspberries, and strawberries. In fact, the US has
become so dependent on honeybees for agricultural purposes that in
2005, for the first time in 85 years, the US allowed for the
importation of honeybees to meet pollination demands. Although millions
of dollars have been invested in an effort to pinpoint the cause, the
honeybee lobby and some environmental organizations say it's not
enough, and argue that if dairy cows were disappearing, the response
would be slightly more engaged.
The decline of bumblebees has received far less attention, though in
the public imagination their plight has often been conflated with that
of the honeybee. Not only do bumblebees pollinate about 15 percent of
our food crops (valued at $3 billion), they also occupy a critical role
as native pollinators. Plant pollinator interactions can be very specific
and thus the loss of even one species carries with it potentially
severe ecological consequences. As E. O. Wilson writes, "If the last
pollinator species adapted to a plant is erased ... the plant will soon
follow." There are close to 50 bumblebee species in the United States
and Canada that have evolved with various plants and flowers over the
course of millions of years; our knowledge of those species, however,
is incredibly weak.
In recent years, there has been much loose talk about the overall
decline of pollinators, and the causes are manifold: habitat loss,
pesticides, the spread of disease, and, without fail, global warming.
The tendency to make sweeping claims about the demise of all
pollinators has led to a lack of specificity when it comes to why
particular species have declined, or in the case of B. franklini, disappeared. One of the only news stories to highlight the plight of bumblebees, published in The Washington Post last August, noted that "the causes of bumblebee decline are not scientifically defined and might be a combination of factors."
A crucial factor, according to Thorp [an entomologist at UC Davis] and other scientists, was the
rise of the commercial bumblebee rearing industry in the early 1990s,
largely for greenhouse tomato pollination. Captive bees, they say,
played a key role in spreading disease, which has led to the decline of
several North American species, all of which belong to the same
subgenus. If their theory proves to be correct, the rapid growth of the
greenhouse tomato industry over the last two decades may have
inadvertently wiped out a number of important native pollinators.
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
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 is an excerpt from a longer article which appears in full here.
Adam Federman is a contributing writer to Earth Island Journal. His last article for the magazine was on illegal logging in Siberia.