A combination of pesticides, pathogens and a lack of pollen-producing flowers is causing a serious decline in the population of bees and other critical pollinators in Minnesota and across the nation, a House committee heard Monday.
Bee researchers delivered an update to the House Environment, Natural Resources and Agriculture Finance Committee, a follow-up to a 2013 session that saw lawmakers direct state agencies to consider planting pollinator-friendly plants when restoring natural habitats.
Among insects, bees are the most important crop pollinator, testifiers said Monday. They described the impact the decline in bee populations could have on global agriculture, including honey producers, and walnut and coffee growers.
Managed bee colonies are experiencing an annual loss of 30 percent of their population since the winter of 2006-2007, said Marla Spivak, a bee researcher at the University of Minnesota.
“That’s really an unsustainable loss,” she said.
A loss of nectar and pollen-producing flowers has contributed to the decline, testifiers said. So, too, have chemicals, including neonicotinyl, an insecticide often used to treat seeds and believed to taint pollen, harming bees.
The chemical is dangerous to bees, University of Minnesota entomology professor Vera Krischik told lawmakers. Unlike insecticides that are sprayed onto plants, neonicotinyls can remain in plants – and their pollen – for years, she said.
In high doses, the chemical can kill, Krischik said. Typically, however, bees ingest it in smaller amounts that blocks memory receptors in their brains, leading them to abandon their hive.
“It’s not going to kill them outright,” Krischik said. “It’s that they can’t remember who they are or where to go.”
The European Union this year banned use of the chemical for two years citing an imminent risk to rapidly declining pollinator populations.