Lawmakers may give cities throughout Minnesota the authority to ban some widely used pesticides as native bumblebee and pollinator populations continue to collapse.

A measure introduced last week by state Rep. Jean Wagenius, DFL-Minneapolis, would essentially give cities their first chance in more than 30 years to have some form of local control over what pesticides can be used within their boundaries. It would grant each city the choice to issue a blanket ban on a group of pesticides that the Minnesota Department of Agriculture has labeled as lethal to pollinators. That list includes neonicotinoids, which are among the most prevalent insecticides used on Minnesota farms and have proved to be particularly harmful to pollinators.

"Minnesotans should be able to protect pollinators if they want to," Wagenius said. "We value local control in this state, and we always have."

A similar proposal that would have given the state's four largest cities broader authority to regulate pesticides failed last year. Concerns were raised at the time that each of the four cities would write their own rules, creating a patchwork of regulations that would make it difficult for homeowners and businesses such as landscapers, nurseries and pest control experts to know what products were legal from one city to the next.

This proposal, however, would grant cities a much narrower exception, Wagenius said. They would pretty much be making a single choice — whether or not to ban a list of "pollinator lethal" insecticides kept by the state.

"This is designed to keep everything consistent," she said.

But the ban would still be enacted from city to city and create the same hard-to-navigate patchwork of rules, said Scott Frampton, past president of the Minnesota Nursery and Landscape Association.

"Local governments lack the expertise and resources needed to assess and restrict these products," Frampton said.

Nearly all insecticides are lethal to pollinators, he said. If cities were to enact a blanket ban, it could keep homeowners from using treatments to fight invasive pests like the emerald ash borer.

"Every product that effectively controls the ash borer contains pollinator lethal language," Frampton said.

But cities would be able to work with the Department of Agriculture, businesses and residents who would be effected by any restrictions before enacting them, said Patrick Hanlon, director of environmental programs for the city of Minneapolis.

"This would be a tool in the tool belt," he said.

Rick Hansen, DFL-South St. Paul, said pesticide users and manufacturers have been making "apocalyptic arguments" for more than 30 years about what will happen if certain insecticides are banned.

"Well, in the meantime bad things have been happening and things are falling apart," he said.

Several species of bees, butterflies and moths have been brought to the brink of extinction in Minnesota over the past two decades.

The population losses are largely because of the region's switch to more intensive and single-crop farming, powerful new pesticides and the loss of food and habitat, according to the U.S. Fish and Wildlife Service.

The agency estimates that the rusty patched bumblebee, Minnesota's fat and fuzzy state bee, has lost 90% of its population in the last 20 years, and that the bees are left in only 0.1% of their historical range.

The Minnesota Department of Natural Resources spent three years from 2014 to 2016 surveying more than 63 prairie sites looking for 13 butterfly species known to live in the state's prairies. It found evidence that just six were still there.

Beekeepers and environmental groups praised the proposal, saying it recognizes how important cities and urban areas are becoming for bee habitat.

Lately, rusty patched bees are rarely, if ever, spotted in places other than major cities. More than 40 cities in the state have declared themselves to be "pollinator friendly," and more are adopting rules and programs to help homeowners and schools plant wildflowers, milkweed and other native grasses to turn lawns into pollinator habitats.

Much of that work is undone when insecticides simply kill off native bumblebees or collapse a honeybee colony, said Willa Childress, Minnesota organizer for Pesticide Action Network North America.

"I think legislators have seen how popular these [lawn conversion] programs are, and how much concern there is for pollinators in really every part of the state," Childress said. "The idea of keeping the status quo or business as usual looks pretty bleak."

Greg Stanley • 612-673-4882