insecticides

Another ban on neonics

July 22, 2024 By EarthWise Leave a Comment

There have been ominous declines in many insect populations. Chief among them have been declines in pollinators, which have severe consequences for our food supply. There are multiple possible causes of these declines and undoubtedly several have been involved simultaneously.

A new study on butterfly populations in the Midwest indicates that agricultural insecticides exerted the biggest impact on the diversity of butterfly populations in the Midwest during the period 1998 to 2014. The biggest culprits were the widely used insecticides called neonicotinoids that are absorbed into the tissues of plants.

Neonics are meant for targeted pesticide use but are often used more broadly, including for corn crops.

Neonics are already well-known to be especially harmful to bees and are gradually being restricted in various places. Quebec province passed restrictions on neonic-treated seeds in 2019. Last December, New York signed into law a phase-out of neonic-treated seeds and a ban on non-agricultural uses of them.

Vermont has now become the second state to ban the use of neonicotinoids by virtue of its state legislature overriding a veto from Governor Phil Scott. The law minimizes the use of neonics by requiring potential users to obtain written exemptions.

Opponents to neonic restrictions claim that slashing their use will greatly reduce crop yields. The experience in Quebec over the past five years is that the Canadian neonic restrictions have reduced corn and soybean crop yields by about 0.5%. As a result of this tiny reduction, there has been a strong reduction in the amount of neonics contaminating waterways.

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Vermont Becomes Second State to Ban Bee-Killing Neonic Pesticides

New ‘Detective Work’ on Butterfly Declines Reveals a Prime Suspect

Photo, posted September 7, 2017, courtesy of Watts via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Banning Neonicotinoid Pesticides | Earth Wise

October 19, 2023 By EarthWise Leave a Comment

New York’s Birds and Bees Protection Act contains a targeted restriction on neonicotinoid pesticides. These widely-used insecticides are absorbed by plants and can be present in pollen and nectar, making them toxic to bees and other pollinators.

Among the largest applications of neonics (as they are called) has been in the form of coatings on crop seeds, such as corn and soybeans. In 2019, Canada’s Quebec province strongly limited neonic use to protect pollinators and the environment. The chemical industry vigorously protested the regulations and claimed that the restrictions would cause the collapse of the grain sector in Quebec.

Seed suppliers began supplying uncoated seeds in 2019 and now there is scarcely any use of coated seeds in the province. Monitoring of over 1,000 agricultural sites has shown that there have been no crop failures related to the pesticide restrictions. In fact, use of the neonics had no economic benefits.

Naysayers warned that even more harmful pesticides or other farming practices would be used instead. But that hasn’t happened either. Some farmers switched to much safer insecticides and others abandoned insecticide treatments altogether.

New York has faced similar opposition by farmers and chemical manufacturers to the Birds and Bees Protection Act and all of the same arguments that have been proven to be invalid in Quebec are being made in New York. Most major environmental advocates in the state support the measures embodied in the legislation. As usual, it boils down to a battle between economic interests and the health of the environment.

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Québec’s experience with pesticide ban offers a glimpse of what New York can expect

Photo, posted August 29, 2013, courtesy of the United Soybean Board / the Soybean Checkoff via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Managing Pests With Cover Crops | Earth Wise

May 18, 2022 By EarthWise Leave a Comment

The use of pesticides in global agriculture brings with it many problems including the killing of non-target, beneficial species as well as reversing pest-management gains from the use of conservation agriculture methods.

In a newly published study by researchers at Penn State University, the use of plant cover, such as cover crops, was shown to potentially be more effective at reducing pest density and crop damage than the application of insecticides without the downsides. Cover crops reduce insect pest outbreaks by increasing pest predator abundance.

Cover crops are plantings that are primarily used to slow erosion, improve soil health, enhance water availability, smother weeds, and help control pests and diseases. Typical cover crops include mustard, alfalfa, rye, clovers, buckwheat, and winter peas. Most cover crops are fairly inexpensive to plant.

Plant cover can provide habitat for populations of natural enemies of pests. Winter cover crops can harbor pest predator populations outside of the growing season of the cash crop. When the cover crop is killed off to allow the growth of the cash crop, residues of the cover crop remain on the soil during the growing season, so they still enhance the habitat for pest predators.

Conservation agriculture includes methods like cover crops, no-till planting, and crop rotation. The use of cover crops constitutes a form of preventive pest management that is an alternative to planting seeds treated with systemic insecticides to control early-season pests. There is also the possibility for integrated pest managements, which is an approach in which insecticides are applied but only when pest numbers exceed economic thresholds despite the use of nonchemical tactics.

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Cover crops more effective than insecticides for managing pests, study suggests

Photo, posted August 8, 2011, courtesy of USDA NRCS Montana via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Harnessing The Smell Of Fear | Earth Wise

September 28, 2021 By EarthWise Leave a Comment

Plant-eating insects present a major problem for farmers and home gardeners. Aphids, for example, are a highly destructive pest to many crops. Their large numbers and ability to transmit plant pathogens make them a persistent problem for growers.

Pesticides are chemical substances that are commonly used to prevent, destroy, repel or mitigate pests. They include insecticides for insects, rodenticides for rodents, herbicides for weeds, and fungicides for microorganisms. According to the U.S. Geological Survey, approximately one billion pounds of these chemicals are used in the United States every year.

But pesticides can also contaminate soil, water, and other vegetation, as well as kill many non-target species. Exposure to these chemicals is dangerous for human health.

According to a new study, researchers from Pennsylvania State University have developed a way to bottle the “smell of fear” produced by predators in order to repel and disrupt pests naturally without the need for these harsh substances. The researchers recently presented their findings at the American Chemical Society meeting.

Aphids happen to be a favorite food of ladybugs. Aphids and other herbivorous insects will steer clear of fields and gardens if they smell predators nearby. The researchers identified and extracted the volatile odor profile from ladybugs. The researchers used the compounds to create a special odor blend that can be used in an essential oil diffuser to spread the scent across a garden or field.

The research team plans to conduct field tests to see if the effects outside are similar to what was observed in the lab. A natural and effective pest repellent would be a big win for people and the planet.

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Protecting gardens and crops from insects using the ‘smell of fear’

Protecting gardens and crops from insects using the ‘smell of fear’ (YouTube)

Photo, posted May 10, 2011, courtesy of DM via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Protecting Bees From Pesticides | Earth Wise

July 15, 2021 By EarthWise Leave a Comment

Studies have shown that the wax and pollen in 98% of beehives in the U.S. are contaminated with an average of six pesticides. These substances lower bees’ immunity to devastating varroa mites and other pathogens. By some estimates, pesticides cause beekeepers to lose about a third of their hives every year on average.

Researchers at Cornell University have developed a new technology that effectively protects bees from insecticides. The insecticide antidote delivery method is now the basis of a new company called Beemunity.

The Cornell researchers developed a uniform pollen-sized microparticle filled with enzymes that detoxify organophosphate insecticides before they are absorbed and can harm bees. Organophosphate insecticides account for about a third of the insecticides on the market. The microparticles have a protective casing that allows the enzymes to move past the bees’ crop (basically the stomach), which is acidic and would otherwise break them down. The safeguarded enzymes then enter the midgut, where digestion occurs and where toxins and nutrients are absorbed. There the enzymes act to break down and detoxify the organophosphate insecticides.

In experimental tests, bees that were fed the enzyme-filled microparticles had a 100% survival rate after exposure to the insecticide malathion. Unprotected control bees died within days.

The Cornell work appears to represent a low-cost, scalable solution to the insecticide toxicity issue and may help to protect essential pollinators.

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Pollen-sized technology protects bees from deadly insecticides

Photo, posted January 30, 2020, courtesy of George Tan via Flick.

Earth Wise is a production of WAMC Northeast Public Radio.

A Promising Malaria Vaccine | Earth Wise

June 23, 2021 By EarthWise Leave a Comment

Malaria is a parasitic disease transmitted through the bite of female Anopheles mosquitoes. Although the disease is both preventable and treatable, an estimated 435,000 people die of it each year, with the majority being children younger than five. Over 90% of all malaria cases and deaths occur in Africa.

The battle against malaria has mostly centered around the use of bed nets, insecticide spraying and antimalarial drugs. To date, there has not been an effective malaria vaccine available.

That may finally be changing. The first vaccinations have begun in Mali in a phase III trial of a malaria vaccine developed by the University of Oxford. The Oxford vaccine showed an efficacy of 77% over 12 months in a phase IIb trial and the hope is that the phase III trial will lead to the licensing of the vaccine in 2023.

Oxford is partnering with the Serum Institute of India for the manufacturing of the vaccine in order to be able to produce high volumes of low-cost vaccine and provide access to countries where it is required the most. The Serum Institute has committed to the production of more than 200 million doses per year once the vaccine is licensed for use, which will be an adequate supply for children most at risk of malaria in sub-Saharan Africa.

The World Health Organization Malaria Vaccine Technology Roadmap has a goal of a malaria vaccine with at least 75% efficacy. Such a vaccine is needed in order to reach the WHO’s goal of reducing malaria deaths by at least 90% by 2030.

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Promising malaria vaccine enters final stage of clinical testing in West Africa

Photo, posted June 9, 2018, courtesy of Mario Yordanov via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Pesticides In The Great Barrier Reef

November 7, 2019 By EarthWise Leave a Comment

Australia’s Great Barrier Reef is one of the greatest natural wonders in the world and it has been under siege by warming waters and ocean acidification. Widespread coral bleaching has damaged or destroyed large portions of the 1,400-mile long coral reef system. But the effects of climate change are not the only threat to the reef. Pesticides found in waterways that flow into the Great Barrier Reef are another serious problem.

According to a new study by the University of Queensland, the combined toxicity of 22 of the most common pesticides that flow into the Reef are not meeting pollution reduction targets.

Different pesticides affect different organisms. Herbicides affect organisms that photosynthesize such as seagrass, corals, mangroves, and algae. Insecticides affect insect larvae in freshwater, and crustaceans such as crabs, prawns, and lobsters. Previous assessments have only examined individual pesticides and only for limited times. The new study has utilized a methodology that estimates the combined toxicity of multiple pesticides found in the waterways that discharge into the Reef and does it for the entire wet season.

The research revealed that the pesticide reduction target set in the Australian Government’s Reef 2050 Water Quality Improvement Plan is not being met. Only one natural resource management region – the Cape York region – was found to be meeting its target.

By having estimates of the risk posed by pesticides in the various regions and individual waterways, governments, farmers, and conservationists can see which areas pose the greatest risk and where to maximize efforts. Stakeholders have to come together to reduce pesticide concentrations through better management practices and by using less toxic pesticides.

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High pesticide concentrations continue to enter Great Barrier Reef

Photo, posted July 29, 2010, courtesy of Kyle Taylor via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Controlling Malaria Without Chemicals

August 28, 2019 By EarthWise Leave a Comment

Nearly half of the world’s population lives in areas vulnerable to malaria. The disease kills roughly 450,000 people each year, most of them children and pregnant women. Malaria is spread by Anopheles mosquitoes and, over time, the mosquitoes have been developing resistance to the chemical insecticides that are used to control them. In addition, there is great concern about the toxic side effects of the chemicals used on the mosquitoes.

About 30 years ago, scientists identified a type of bacteria that kills Anopheles, but the mechanism was not understood. As a result, the bacteria could not be replicated or used as an alternative to chemical insecticides.

But now, an international research team, headed by researchers at UC Riverside, has identified the neurotoxin produced by the bacteria and has determined how it kills Anopheles. The work is described in a paper published in Nature Communications.

It took the team 10 years to achieve a breakthrough in understanding the bacteria. Modern gene sequencing techniques were the key.

While many neurotoxins target vertebrates and are highly toxic to humans, the neurotoxin that kills Anopheles mosquitoes does not affect humans, vertebrates, fish, or even other insects. Known as PMP1, the substance is not even toxic to mice when given by direct injection.

The team has applied for a patent on this discovery and hopes to find partners to help them develop the bacteria-based insecticide.

There is a high likelihood that PMP1 actually evolved to kill the Anopheles mosquito. This finding opens the door to new avenues of research into other environmentally friendly insecticides that would be targeted at other disease-spreading pests.

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