Proceedings of the National Academy of Sciences of the US Archives

Proceedings of the National Academy of Sciences of the US

November 29, 2023

Pesticides continue to plague bee health, study warns

By Shannon Kelleher

Pesticides sprayed on farmland continue to harm bumblebees in Europe, underscoring a need for more protective regulatory oversight, according to a new study that revealed how bees respond to real-world pesticide exposure at 106 sites across eight countries.

The analysis, part of a project called PoshBee that aims to monitor and improve bee health across Europe, went beyond standard field experiments that measure how bees respond to a single substance in a test environment. Instead, the researchers studied bumblebees in actual farm landscapes – apple and rapeseed fields – treated with multiples pesticides. Bumblebee colonies with greater toxicity from pesticides in their pollen had fewer total cocoons, weighed less altogether, and had fewer new queens, according to the study, which was published Wednesday in the journal Nature. Insecticides, including neonicotinoids, pyrethroids, and organophosphates, posed a greater risk to the bees than other types of pesticides.

“This is a very important study,” said Margaret Reeves, a senior scientist at the Pesticide Action Network (PAN) North America who was not involved in the study. “Pesticides are almost never used in isolation [and] can drift long distances, with those used in close proximity to one another especially likely to interact. Much of this we simply don’t understand because various kinds of mixtures are seldom studied.”

“If pesticides in agricultural fields pose the problems described to bees, just imagine what these pesticides are doing to the millions of field workers in those same fields,” she added.

The findings point to a need to monitor approved pesticides after farmers begin spraying them in the environment, a strategy that could also safeguard species important for pest control and soil quality on farms, said Jessica Knapp, an assistant professor of botany at Trinity College Dublin in Ireland and an author of the study.

“For us, it’s not necessarily that [risk assessment] should become tighter, it’s that it should become more realistic with what these species are actually exposed to in real landscapes,” she said. “Once [pesticides] go through all the regulation, the testing kind of stops, which is obviously nonsensical because we don’t know what is happening in these real environments. That’s where we really want a change.”

The study comes on the heels of the European Parliament’s failure last week to pass the Sustainable Use of Plant Protection Products Regulation (SUR), proposed legislation that included targets to slash the use and risk of chemical pesticides in the European Union in half by 2030. SUR was rejected because decision makers felt that pesticide reduction wouldn’t be economically viable for farmers, said Knapp, adding that farmers need such protections to ensure healthy landscapes for future generations.

“Countries outside the [European Union] should also take note of these results, as many nations have looser pesticide regulations that may lead to more magnified impacts on wild bees,” said Clara Stuligross, a postdoctoral researcher at the University of California, Riverside who was not involved in the study.

March 24, 2023

As US pushes “climate-smart” agriculture, hopes and fears collide

By Keith Schneider

For decades, leading US farm leaders have likened efforts to rein in harmful climate change as attacks on agriculture itself, aligning with oil and gas industry groups to block policies aimed at reducing greenhouse gas emissions.

That stance has slowly been shifting in recent years, and now, fueled by $3.1 billion in federal grants, farm country is poised to shape a new era of “climate-smart” agricultural practices and take a significant role in addressing the dire consequences of a warming planet.

The actions can’t come fast enough. A panel of international scientists warned this month that the world faces a “rapidly closing window of opportunity to secure a liveable and sustainable future,” and that the actions implemented over the next few years will have consequences “now and for thousands of years.”

The Biden Administration’s focus on agriculture is just one part of a larger effort to address climate change, but it is a key element. By funding 141 experimental projects, the administration is hoping to push an industry currently responsible for generating 10% of U.S. greenhouse gases, to the front of the nation’s work to reduce carbon emissions.

The first grants from the US Department of Agriculture (USDA), for 70 large projects, were awarded in September. A second round of funding, for 71 smaller projects, was awarded in December.

The scope of the climate-smart program is expansive. Grants range from $271,200 to teach climate-friendly practices to immigrant farmers in Iowa to $95 million to encourage grain farmers in 12 Midwest states to use cultivation methods that build soil fertility. In between are projects to expand organic and sustainable agriculture, sequester carbon on pastures where livestock graze, and develop carbon-reducing cultivation methods on farms operated by African Americans and Native Americans.

In all, more than 60,000 farms and 25 million acres of crop and rangeland are involved, with spending reaching all 50 states and Puerto Rico, according to the USDA..

Considerable sums are also earmarked for development of scientific methods to effectively measure whether these climate-smart practices actually meet a program goal of sequestering 60 million metric tons of carbon.

When making the rounds at annual farm conferences across the country over the winter, Agriculture Secretary Tom Vilsack repeatedly declared that a “transformational” new era had opened for U.S. agriculture.

Grant recipients such as Marbleseed, a Wisconsin nonprofit that trains farmers in organic agriculture, say the government support is long overdue. Marbleseed is part of a partnership receiving a $4.5 million, five-year grant to train farmer in 14 Midwest and southern states on how to improve soil fertility.

“We’ve been a tiny voice shouting into the storm for a very long time,” said Tom Manley, Marbleseed program director. “They finally are starting to hear us.”