Cut in pollinators puts food crops at a big risk

Non-native parasitic mites have killed thousands of U.S. honeybee colonies.
SALT LAKE TRIBUNE
Numbers of honeybees, wild bumble bees and other pollinators have declined, raising the risk of plant extinction and threatening the nation's food crops, says a report from the National Research Council.
The nationwide shortage is significant enough that honeybees had to be brought in from Canada and Mexico last year for the first time since 1922, when the Honeybee Act banned imports for fear they would introduce non-native pests, according to the report.
Those fears were justified. Studies show that U.S. honeybee populations have dropped since the 1980s with the introduction of non-native parasitic mites that have killed off thousands of colonies across the nation.
Honeybees in particular are critical to the U.S. food supply, pollinating more than 90 food crops. In California, for example, it takes about 1.4 million colonies of honeybees to pollinate 550,000 acres of almond trees.
"Honeybees are the premier pollinator, accounting for 10 billion to 20 billion worth of food per year in America alone," said Gene Robinson, head of the Department of Entomology at the University of Illinois, Urbana-Champaign, and member of the panel that issued the report. "The declines in population threaten our nation's food supply."
Long-term trends for wild pollinators, such as butterflies, bats, hummingbirds and bumblebees also are showing population declines, the report noted. The bumble bee -- like the honeybee -- has been hurt by the introduction of non-native parasites and losses in the bat population that can be attributed to the destruction of cave roosts.
Although consequences of wild pollinator declines in nonagricultural settings are difficult to track, one result could be a greater vulnerability of some plant species to extinction. Few plants rely on a single pollinator, but certain plant species could be at risk, says the report by the Research Council, which is part of the National Academy of Sciences, both nonprofit institutions under a congressional charter.
In Utah, beekeeper Darren Cox lost more than 1,000 of his hives in 2003 and again in 2004, when nearly 500 more hives were lost from irresponsible pesticide spraying that drifted over to his hives, he said.
Situation in Utah
Although pesticide labels instructing users not to spray during times when bees are foraging have the force of federal law, Utah property owners and land managers had enjoyed unprecedented exemptions until a rule change brought the state into line with federal guidelines in July. Previously, they could use "pesticides known to be harmful to honeybees" and they could spray the toxic chemicals during daylight hours when bees pollinate crops and plants.
Cox thinks fewer bees have died since the state pesticide regulation was changed, although he won't know for sure until January, when his hives come out of hibernation. A new problem is that life cycles of his queen bees have inexplicably become shorter, down from three or four years to 12 months. When queens die, hives cannot reproduce.
"Unlike worker bees, queens are fed pollen all their lives," said Cox. "If the pollen is contaminated, her fertility is affected, just like hemlock is to a cow."