In a tragic start to National Pollinator Week, the trees rained bees starting on Saturday June 15 when 25,000 bumblebees dropped into a Target parking lot in Wilson, Oregon, the largest bee kill ever recorded.
Pesticides containing dinotefuran, part of a group of insecticides known as neonicotinoids, had been sprayed on the trees to control aphids, the Oregon Department of Agriculture determined. The pesticide, sold under the name Safari, was applied to the linden trees surrounding the parking lot to keep aphids from leaving their sticky substance on parked cars.
“To our knowledge, this incident is the largest mass poisoning of bumble bees ever documented, and thankfully ODA is taking the issue very seriously,” said Mace Vaughan, pollinator conservation director of the Xerces Society for Invertebrate Conservation, a Portland-based conservation group that focuses on bees as well as other pollinating insects.
The number of bees killed may have been much higher. Xerces Society biologist Rich Hatfield estimated that more than 50,000 bumblebees may have died, representing more than 300 wild colonies.
“Each of those colonies could have produced multiple new queens that would have gone on to establish new colonies next year,” he said in the Xerces Society statement. “This makes the event particularly catastrophic.”
The bees were still dying on Wednesday, The Oregonian reported.
"Yellow-faced bees fell from the trees, twitching on their backs or wandering in tight circles on the asphalt," the newspaper said. "Some honeybees and ladybugs were also found dead. A few dead bumblebees even clung to linden flowers, while hundreds littered the lot."
National Pollinator Week runs from June 17 to 23, the annual campaign to “raise awareness about the importance of bees, birds and other pollinator species to agriculture, forest and grassland environments and other ecosystems,” said USDA Secretary Tom Vilsack on the group's site. Pollinators are birds, bats, butterflies, moths, flies, beetles, wasps and small mammals in addition to bees.
A host of other insects were also killed when the flowering trees were doused in insecticide, The Oregonian reported. The bees’ loss is especially disturbing given that bees pollinate nearly a third of our food, with crops valued at $217 billion. As for the aphids, the cars and trees would have been better off keeping them.
“Beyond the fact that a pesticide was applied to plants while they were attracting large numbers of bees, in this case the pesticide was applied for purely cosmetic reasons,” said Scott Black, executive director of the Xerces Society. “There was no threat to human health or the protection of farm crops that even factored into this decision.”
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