Herbicide limit asked to save butterflies

With monarch butterfly populations rapidly dwindling, a conservation organization this week asked the U.S. Environmental Protection Agency to implement tougher rules for the weed killer glyphosate – first marketed under the brand name Roundup – to save one of America’s most beloved insects from further decline.

In a petition, the Natural Resources Defense Council argued Monday that current uses of glyphosate are wiping out milkweed, the only plant upon which monarch caterpillars feed.

Since federal glyphosate rules were last updated a decade ago, its use has spiked tenfold to 182 million pounds a year, largely due to the introduction and popularity of corn and soybeans genetically modified to resist the herbicide, the petition says.

The EPA is scheduled to complete a new review of glyphosate rules in 2015. But “given the rapid decline in monarch numbers, the EPA should take immediate steps to review and restrict glyphosate’s uses,” the petition says.

The petition asks the EPA to consider preventing the use of glyphosate and other weed killers along highways and utility rights of way where milkweed could grow freely without interfering with maintenance or emergency crews.

It also asks that farmers be required to establish herbicide-free safety zones in or around their fields, and urges the EPA to ensure that any new safeguards on glyphosate don’t lead simply to more use of other weed killers that would be equally bad for monarchs and may pose health risks.