The farm bill and the precipitous decline of monarch butterflies

Benjamin Vogt moved to Nebraska in 2003 and unexpectedly fell in love with the prairie. It began when he noticed caterpillars on milkweed in his garden. His first reaction was to spray them into oblivion, but instead he went inside and began researching native plants and insects, which led him to discover what the cornfields around his house used to look like. Now, he wants to quit his teaching job, buy all the farmland he can afford and convert it to grassland. "The government's not going to do it," he says. "If anything's going to change, it's got to be private landowners."

Part of the reason Vogt wants to return farmland to prairie is to help save monarch butterflies, the black-and-orange pollinators that lay eggs only on milkweed. Every year, monarchs that summer east of the Rockies migrate thousands of miles to Mexico, stopping in the Great Plains to forage and breed. In 1996, overwintering monarchs blanketed 45 acres of Mexican forest. This year, they covered only 1.6 acres, suggesting that their numbers – already at a record low – have dropped again by half, to about 33 million. One of North America's great wildlife migrations may be in its death throes.

Monarch declines were once blamed primarily on Mexican deforestation. But not today: "The forest is as well protected as it's ever been," says Mace Vaughan, pollinator program director for The Xerces Society, an invertebrate conservation group. Blame has shifted to the loss of milkweed in the butterflies' summer range. The plant declined by 58 percent in Plains states from 1999 to 2010. Monarch populations dropped 81 percent in the same period.

The $956 billion Farm Bill – signed into law Feb. 7 after four years of debate – includes a few measures to help monarchs and other pollinators. A provision designed to discourage sodbusting, for example, limits farmers' ability to insure crops against bad weather or disease on freshly plowed grasslands in Montana, the Dakotas and three other states. The bill also reauthorizes "pollinator protection" clauses that advocates fought to get in the 2008 Farm Bill, including mandated research and monitoring.

Yet the new bill also maintains incentives for farmers to plant ever more corn and soybeans – policies that have caused researchers to project a rate of Northern Plains grassland destruction greater than that of the Amazon rainforest. Direct subsidies for corn and soybeans have been replaced with subsidized crop insurance and "price guarantees," but critics argue that the end result is the same. Plus, $6 billion was cut from conservation programs, and the maximum acreage that can be enrolled nationally in the Conservation Reserve Program – which pays farmers to take environmentally sensitive fields out of production – was reduced by 8 million acres. Even when the CRP is strongly funded, participation is voluntary; hundreds of thousands of acres of milkweed-rich CRP land have been plowed under in recent years due to corn and soy incentives.

Another powerful incentive is the 2007 Renewable Fuel Standard, which mandates that more domestic gasoline be made from biofuels like corn-based ethanol. Chip Taylor, a University of Kansas insect ecologist, points out that 20 million new acres of corn and soybeans were planted in the last seven years, compared to 9.5 million in the previous decade. "This increase is largely due to the ethanol mandate," he writes.

Ethanol subsidies may help struggling farms, but Senators Dianne Feinstein, D-Calif., and Tom Coburn, R-Okla., argue that they also raise food costs and encourage sodbusting. The pair co-authored a bill in December to eliminate the corn ethanol mandate. The U.S. Environmental Protection Agency, meanwhile, proposed cutting ethanol requirements by 16 percent, but for now, subsidies remain.

Still, plowing up prairie doesn't necessarily condemn monarchs. Commercial crops can be grown alongside milkweed, and were for many years before the introduction of genetically modified super-crops like Roundup Ready soybeans and corn, which are engineered to survive chemical showers that kill almost everything else – including milkweed. The U.S. government could regulate these crops and their companion herbicides more strictly, as the European Union does, but the enormous influence of agribusiness leaves little hope that the feds will move quickly enough to rescue the swiftly declining butterflies.

Instead, the task may fall to the private sector or to states, which can help by simply not mowing roadsides. Laurie Davies Adams of the Pollinator Partnership says that after publicity about plummeting monarch populations, the president of one large company asked her whether planting milkweed around his factories would help. Yes! she replied.

Farmers and landowners can also help. The Xerces Society is working with federal agencies like the Forest Service to protect milkweed habitat on public land (see map, above), and helping vendors produce more milkweed seeds for gardeners like Benjamin Vogt. "If the ship's going down ecologically," Vogt says, "I want to scream and rant and rail. For me, that means buying as much land as we can and reverting it to prairie. I see it as a moral and ethical imperative."

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