Minnesota's largest county will avoid the use of neonicotinoid pesticides and will plant bee- and butterfly-friendly native plants when possible under a resolution approved by the St. Louis County board Tuesday.

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The board unanimously passed the resolution that calls for county actions to bolster pollinator populations "and provide the framework for pollinator-friendly policies in St. Louis County."

Scientists have linked the use of certain pesticides containing neonicotinoids and the huge decline in pollinators such as native bees, domestic honeybees and butterflies.

Butterflies, especially monarchs, also are facing a habitat issue, with critically important milkweed being nudged out of rural areas by heavy use of herbicides and cropland expansion.

Under the resolution adopted at the board's regular meeting, held this week in Chisholm, the board resolved that "the county shall refrain from the use of pesticides from the neonicotinoid family excepting for imminent threat to forest health and/or loss on county owned and administered property," and that the county "shall continue its efforts to purchase seeds and plants favorable to bees and other pollinators with a preference for native species which enhance pollinator habitat."

"The groups that asked us to do this said the best part is that it's a public statement by a government agency that this is an important issue," said Frank Jewell, county board chairman.

In March, 2016, the Duluth City Council passed a resolution to stop using neonicotinoid pesticides on city property and which instructed staff members to steer clear of plants that have been treated with the insecticide.

Earlier this year the U.S. Fish and Wildlife Service formally declared the rusty patched bumblebee on the federal endangered species list, the first bumblebee ever given Endangered Species Act protections.The chubby bee with a rusty patch on its back once thrived in 28 states across the Upper Midwest and East Coast as well as large parts of Canada. But in the past two decades the bee has disappeared from nearly 90 percent of its historic range - seen in the past 15 years in only 13 states, including Minnesota and Wisconsin, as well as Ontario.

Gov. Mark Dayton last year took steps to limit the use of neonicotinoids by state agencies, although the effort doesn't restrict farmers' use of seeds that are coated in the chemicals, a common application. Minnesota lawmakers in May killed legislation that would have given the state Department of Agriculture authority to prohibit seeds coated with insecticide. Ontario last year passed a law that required farmers to prove they needed the pesticide before planting any seeds coated with it.

According to the The Xerces Society for Invertebrate Conservation, neonicotinoids are a group of insecticides used widely on farms and in urban landscapes. They are absorbed by plants and can be present in pollen and nectar, making them toxic to bees and butterflies, several studies have shown. The chemicals affect the central nervous system of insects, resulting in paralysis and death, and include imidacloprid, acetamiprid, clothianidin, dinotefuran, nithiazine, thiacloprid and thiamethoxam.