bees

July 11, 2024

Air pollution threatens key crop pollinators, study finds

By Shannon Kelleher

Air pollution jeopardizes bees and other pollinators essential for food production, according to a new study that sheds light on a significant but underrecognized threat to beneficial insects.

In a study published Thursday in the journal Nature Communications, researchers found that bees, as well as some moths and butterflies, became about a third less efficient at foraging for food, on average, after exposure to elevated air pollution levels. The findings were based on an analysis of data from 120 scientific papers on how 40 types of insects respond to ozone, nitrogen oxides, sulfur dioxide and particulate matter.

“Air pollution is not generally considered as a driver of pollinator declines, but these results indicate that air pollution should be considered as a further factor that is driving pollinator declines,” said James Ryalls, an ecologist at the University of Reading and an author of the study. Declines in pollinator health can translate to declines in crop yields, Ryalls said.

The researchers noted that insects generally seen as harmful to agriculture, such as sap-sucking aphids, did not experience significant declines in their ability to forage from exposure to air pollution.

Air pollution may be more disruptive for bees and other insects because it muddles the chemical signals they use to communicate and sense their surroundings, the researchers suggest, while pests tend to rely more heavily on visual cues or others.

Surprisingly, even low concentrations of air pollutants below the threshold considered safe for humans harmed the pollinators, Ryalls said.

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February 14, 2024

Pesticide-treated seeds harm earthworms, study finds

By Shannon Kelleher

Commonly used pesticides pose a toxic threat to earthworms, creatures considered crucial for the health of soil used to grow crops, according to a new study published Wednesday.

The study builds on evidence that a class of insecticides called neonicotinoids, or neonics, are harming a range of species important for planetary health. Neonics have been banned in many countries but are popular with farmers in the United States.

The authors of the new study said they found that when earthworms were exposed to four different types of neonics, as well as the fungicide difenoconazole, they suffered damage to their mitochondrial DNA and gained significantly less weight than earthworms not exposed to the chemicals. The pesticides were especially damaging when the worms were exposed to a neonic plus the fungicide in combination.

The findings were published in the journal Environmental Science & Technology Letters.

“We need to re-evaluate the toxicity of neonics and the synergistic effects of neonics and systemic pesticides in those non-target organisms when they are applied to soil simultaneously,” said Chensheng (Alex) Lu, a professor at Southwest University in Chongqing, China and an author of the study.

“The contribution of earthworms to crop yields is as essential as pollination done by honey bees,” he added. “A healthy soil is simply not possible without the presence of earthworms.”

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 27, 2023

Letter to the EPA: Take action on “Devil’s bargain” pesticides

An Open Letter to: Michael Regan, Administrator; Michal Freedhoff, Assistant Administrator, Office of Chemical Safety and Pollution Prevention; and Ed Messina, Office of Pesticide Programs Director, Environmental Protection Agency

The environment needs protection from neonicotinoid-coated pesticidal seeds, which are by far the greatest single insecticide application across the country, covering more than 100 million acres. Fundamental ecosystem integrity, plus the welfare of millions of birds and other animals where the coated seeds are planted, are at risk. You can be the difference makers if you seize the opportunity.

You know, as we NGO-types have recited to you in the past through broadly-supported letters and petitions, that a major body of evidence now shows neonic-coated seeds are the Devil’s bargain. While there may be some effective uses, they are mostly used prophylactically with no assessment of need. And yet they do great harm to essential pollinators, beneficial insects, and farmland birds, while contaminating the environment with their toxins.

In Ontario, Canada, when farmers were compelled to prove they needed to use neonic-coated seeds before being allowed by the provincial government, their use declined by a huge margin with no adverse economic effect.

Neonics have largely been banned in Europe since 2015. But, in the US, their excess production as a result of your agency’s leniency is a waste that resulted in the ongoing tragedy in Mead, Nebraska, where AltEn gathered about 80,000 tons of unwanted neonic-coated seeds in order to distill them for ethanol but instead ending up contaminating the environment to the tune of roughly $100 million in total damages. EPA’s uncritical approval of these seeds enabled the Mead disaster.

Of all the environmental threats in the United States, pesticides are conceptually the easiest to prevent because all the approved products out there resulted from registrations by your agency. But I am not asking you to cancel registrations, I am just asking you to take a closer look at EPA’s interpretation and regulatory issues that have allowed the harms of neonic-coated seeds to spin out of control.

March 13, 2023

Scientists warn pesticide impacts may be worse than we thought

In California, regulators have rolled out a plan to eliminate “high-risk” pesticides from agricultural and urban use. In Mexico, officials have announced a ban on the widely used weedkiller glyphosate. And in Canada, regulators have implemented some new pesticide restrictions and are reviewing the potential for others.

The moves, which are also playing out in various forms around the United States, have drawn opposition from chemical and farm industry forces. But supporters say they don’t go far enough to adequately protect human and environmental health.

Three University of British Columbia researchers recently published a paper that summarizes what they say is a growing body of evidence showing that pesticides are having harmful ecological impacts beyond what is already well understood, and that these impacts are not being recognized by current testing and regulations. The authors of the paper looked at dozens of studies to draw their conclusions.

The New Lede had a conversation with lead author Risa Sargent about the team’s findings. Sargent is an associate professor of applied biology within the Faculty of Land and Food Systems at the University of British Columbia. She and colleagues reviewed studies from around the world, finding alarming results.