Pesticide usage in the US has declined by more than 40 percent over the last three decades, and some organisms, including mammals and birds, have benefitted from the reduction in pesticide usage and improvements in product design, according to a study published April 2 in Science. But an increase in pesticide potency has come at the expense of other species’ health.

“Compounds that are particularly toxic to vertebrates have been replaced by compounds with less vertebrate toxicity, and that is indeed a success,” coauthor Ralf Schulz, an ecotoxicologist at the University Koblenz and Landau in Germany, tells The Guardian. “But at the same time, pesticides became more specific, and therefore, unfortunately, also more toxic to ‘non-target organisms’, like pollinators and aquatic invertebrates.”

Schulz and his team combined self-reported US Geological Survey data on farmers’ use of 381 pesticides between 1992 and 2016 with data from the Environmental Protection Agency (EPA) on the toxic dosage effects of these chemicals on eight types of animals and plants: fish, mammals, birds, pollinators, terrestrial and aquatic invertebrates, and terrestrial and aquatic plants. Using the two data streams, the authors calculated a “total applied toxicity” value for each group to assess changes in pesticide usage and their effects over time.

Taken together, the results show that despite the drop in their usage, pesticides continue to negatively affect many different forms of life. The toxicity level of pesticides doubled for aquatic invertebrates such as plankton and insect larvae, and the same was true of important pollinators such as bees. Mammals and birds were the only groups to benefit over the course of the study—their toxicity values dropped by more than 95 percent—but even these groups may be negatively affected through changes to the food web.

“The bottom line is that these pesticides, once believed to be relatively benign and so short-lived that they would not damage ecosystems, are anything but,” Lynn Goldman, a former EPA scientist who was not part of the study, tells the Associated Press.

The results are largely a reflection of how technology has changed the landscape of pesticide design. Pesticides have become stronger, sometimes requiring only 6 grams per hectare compared with several kilograms of older chemicals such as organophosphates and carbamate pesticides, Science reports. And companies have also gotten better at tailoring their products to target particular agricultural pest species while minimizing unintended damage to other organisms, although they aren’t so specific that they can distinguish between pests and potentially beneficial insects.

This tradeoff between vertebrates and invertebrates could have unintended consequences for the health and functioning of ecosystems, says Schulz. Aside from their importance as pollinators, many insect species are food for other animals, and the current study does not measure the accumulation of toxins up the food web, something Schulz tells the AP he would like to see followed up on in future research.

In the current study, plants also registered increasing levels of toxicity, even among species that have been genetically modified to reduce their need for pesticides. One strain of corn, for example, had been modified to produce an insect-killing chemical, but as the insects have evolved a tolerance to the chemical, farmers have responded with more-frequent applications of other pesticides. Wild plants are also susceptible to pesticide toxicity, especially from commonly used weed killers, and their use risks reducing the overall plant diversity in undeveloped areas surrounding agricultural fields.

To avoid this future, countries around the world will need to think more critically about their use of pesticides, John Tooker, an entomologist at Penn State who was not involved in the research, tells Science. “The patterns in the US pesticide use and toxicity data should be a cautionary tale for the rest of the world, much of which seems to be leaning more heavily on pesticide use rather than ecological interactions for pest control.”

https://www.the-scientist.com/news-opinion/us-pesticide-use-is-down-but-damage-to-pollinators-is-rising-68635

PermeateFree said:

Pesticide usage in the US has declined by more than 40 percent over the last three decades, and some organisms, including mammals and birds, have benefitted from the reduction in pesticide usage and improvements in product design, according to a study published April 2 in Science. But an increase in pesticide potency has come at the expense of other species’ health.

“Compounds that are particularly toxic to vertebrates have been replaced by compounds with less vertebrate toxicity, and that is indeed a success,” coauthor Ralf Schulz, an ecotoxicologist at the University Koblenz and Landau in Germany, tells The Guardian. “But at the same time, pesticides became more specific, and therefore, unfortunately, also more toxic to ‘non-target organisms’, like pollinators and aquatic invertebrates.”

Schulz and his team combined self-reported US Geological Survey data on farmers’ use of 381 pesticides between 1992 and 2016 with data from the Environmental Protection Agency (EPA) on the toxic dosage effects of these chemicals on eight types of animals and plants: fish, mammals, birds, pollinators, terrestrial and aquatic invertebrates, and terrestrial and aquatic plants. Using the two data streams, the authors calculated a “total applied toxicity” value for each group to assess changes in pesticide usage and their effects over time.

Taken together, the results show that despite the drop in their usage, pesticides continue to negatively affect many different forms of life. The toxicity level of pesticides doubled for aquatic invertebrates such as plankton and insect larvae, and the same was true of important pollinators such as bees. Mammals and birds were the only groups to benefit over the course of the study—their toxicity values dropped by more than 95 percent—but even these groups may be negatively affected through changes to the food web.

“The bottom line is that these pesticides, once believed to be relatively benign and so short-lived that they would not damage ecosystems, are anything but,” Lynn Goldman, a former EPA scientist who was not part of the study, tells the Associated Press.

The results are largely a reflection of how technology has changed the landscape of pesticide design. Pesticides have become stronger, sometimes requiring only 6 grams per hectare compared with several kilograms of older chemicals such as organophosphates and carbamate pesticides, Science reports. And companies have also gotten better at tailoring their products to target particular agricultural pest species while minimizing unintended damage to other organisms, although they aren’t so specific that they can distinguish between pests and potentially beneficial insects.

This tradeoff between vertebrates and invertebrates could have unintended consequences for the health and functioning of ecosystems, says Schulz. Aside from their importance as pollinators, many insect species are food for other animals, and the current study does not measure the accumulation of toxins up the food web, something Schulz tells the AP he would like to see followed up on in future research.

In the current study, plants also registered increasing levels of toxicity, even among species that have been genetically modified to reduce their need for pesticides. One strain of corn, for example, had been modified to produce an insect-killing chemical, but as the insects have evolved a tolerance to the chemical, farmers have responded with more-frequent applications of other pesticides. Wild plants are also susceptible to pesticide toxicity, especially from commonly used weed killers, and their use risks reducing the overall plant diversity in undeveloped areas surrounding agricultural fields.

To avoid this future, countries around the world will need to think more critically about their use of pesticides, John Tooker, an entomologist at Penn State who was not involved in the research, tells Science. “The patterns in the US pesticide use and toxicity data should be a cautionary tale for the rest of the world, much of which seems to be leaning more heavily on pesticide use rather than ecological interactions for pest control.”

https://www.the-scientist.com/news-opinion/us-pesticide-use-is-down-but-damage-to-pollinators-is-rising-68635

read that, cheers, nice picture too

I’ve never used pesticides.
Management is an issue that is best avoided by using pesticides and herbicides.
Management however, can allow for a natural balance which reduces and eveb begates the need for pesticides.

> Pesticide usage in the US has declined by more than 40 percent over the last three decades

Good. I have a personal hatred of insecticides.

> Pesticides have become stronger, sometimes requiring only 6 grams per hectare compared with several kilograms of older chemicals such as organophosphates and carbamate pesticides

This needs looking into. “Stronger” and “More focussed” are not synonymous. Looking back to the Guardian article https://www.theguardian.com/environment/2021/apr/01/toxic-impact-of-pesticides-on-bees-has-doubled-study-shows

“Modern pesticides have much lower toxicity to people, wild mammals and birds and are applied in lower amounts”. Good. “The study shows the higher toxicity outweighs the lower volumes, leading to a more deadly overall impact on pollinators and waterborne insects such as dragonflies and mayflies.” – bad. We urgently need insecticides that affect only caterpillars, or affect only beetle larvae, or even better are tailored to affect only one specific species.

> plants also registered increasing levels of toxicity, even among species that have been genetically modified to reduce their need for pesticides. One strain of corn, for example, had been modified to produce an insect-killing chemical, but as the insects have evolved a tolerance to the chemical.

Oh dear. I had thought that this was one of the great successes of genetic engineering. By getting plants to express small amounts of nsect poison, this had been supposed to greatly reduce the need for and unintended deaths by fugitive insecticide sprays.

“The research is based on the use and toxicity of 380 pesticides applied in the US from 1992 to 2016.”

Nice work! (Personal gripe, I wish newspaper articles would distinguish between “pesticides” and “insecticides”, there are a lot of pesticides that are not insecticides). Checking technical article, yes this 380 does include herbicides and fungicides as well as insecticides.

“Pesticides are one factor cited by scientists for the plunging populations of some insects.”

Well duh.

It was worse in the past, with the claim in 1910 that there was not one mosquito left alive in the country of Panama, and the mass spraying of insecticides on wetlands worldwide prior to 1962.

Technical article: https://science.sciencemag.org/content/372/6537/81

“the replacement of organophosphorus and carbamate insecticides reduced the total toxicity to mammals and birds by a factor of nine” – good. Amphibians also, I hope. Amphibians are accutely affected by insecticides.