Tag Archives: pesticide

Scientists use ‘smell of fear’ to ward off insect pests from crops and gardens

Herbivorous insects represent a major threat to growing crops either directly by destroying the plants’ stems, fruits, or roots, or indirectly by transmitting bacterial, viral, and fungal infections to the crop. In response, humans have invented pesticides, only to have the pests strike back by developing increasingly strong resistance due to the pressure of natural selection. This problem has been bugging researchers at Pennsylvania State University for some time. In a new study, they present an out-of-the-box idea involving the ‘smell of fear’ to ward off insects from crop fields and gardens.

Eau de ladybug

Many animals sharpen their senses when danger is lurking. For instance, your sense of smell will alert you of a potentially deadly fire. The natural reaction is to get out of harm’s way. Insects are no exception — in fact, many are much more sensitive to odors than humans since chemical communication is such an essential adaptation for insects’ survival.

Insects secrete and detect all sorts of pheromones that help them reproduce and communicate with members of their own species. They can also use odors to detect threats. For instance, when aphids detect chemicals secreted by ladybugs, their natural predators, the insects will tend to flee. The researchers at Penn State wondered if they could somehow exploit this chemical response to ward off pests of crops.

“As our global population continues to increase, there is a growing need to enhance crop protection so that we can make enough food to sustain the human population. Insect pests are one of the biggest challenges in agricultural production, worldwide and managing them is crucial. However, pesticides that are commonly used to combat these pests can be problematic for human and environmental well-being and are farmers are increasingly experiencing pesticide bans and restrictions as well as pest resistance to this control method that render them less effective. Because of this, we are inspired to identify and develop sustainable ways to reduce insect pest pressure with reduced or eliminated use of insecticides,” Sara Hermann, Assistant Professor of Arthropod Ecology and Trophic Interactions at Penn State, told ZME Science.

“One of our major goals is to attempt to enhance the impact of predatory insects on pest herbivores to reduce the negative influence of these pests on crop plants. Rather than simply encouraging predatory insects to eat the pests, in our lab we are working to harnessing the fear or being eaten to disturb pests in ways that will limit their impact on crop plants,” she added.

Hermann and Jessica Kansman, a postdoc at Penn State, ran field experiments showing that aphids and other herbivorous insects will steer clear of fields and gardens where they smell the scent of predators. What’s more, exposure to these chemicals slows the reproduction rates of the insects and increases their ability to grow wings, both natural behaviors meant to better equip them to escape threats. The question remained which compounds exactly caused the aphids to react to the ladybug’s chemical presence.

In their new study, the researchers at Penn State used gas chromatography-mass spectrometry to identify and extract the volatile odors secreted by ladybugs. They then hooked up the antennae of live aphids to an electroantennogram (EAG) machine and exposed them to each individual chemical component released by the ladybugs in order to see which compounds they could detect.

That’s easier said than done since insect ecology involves its own fair share of challenges, from braving bad weather during field work to handling delicate specimens. But the researchers managed to rise to these challenges.

“Aphids are TINY. So, we have had to get creative to assess their behavior, using specialized tools and techniques rather than visual observations.

“Ecological research can be really funny, because in order to isolate the specific interactions we seek to understand, we have to get creative. I often say that more than 50% of the job is arts and crafts, to develop arenas where we can do our experiments that just are not available for purchase. For this project, I had to teach the entire lab how to use a sewing machine so we could fashion field cages that would be able to exclude organisms other than our aphids and ladybeetles. Justifying our spending and purchasing must be hilarious to read in the business office!” Hermann said.

Of the numerous compounds released by the ladybug, aphids had the strongest reaction, judging from the EAG signal, to methoxypyrazines, such as isopropyl methoxypyrazine, isobutyl methoxypyrazine, and sec-butyl methoxypyrazine.

Using these starting chemicals, the researchers developed a special odor cocktail which now has to undergo testing in the field. The cocktail is sprayed from an essential oil diffuser in order to determine whether the odors are indeed effective in the real world at warding off pests from crop fields and gardens. These volatile chemicals are dispersed into the atmosphere rather than being sprayed onto plants.

“Because of this, organisms, plants and humans would not come in contact with the product making the toxicity risk quite low and the management strategy safe. We are examining the potential for these odors to influence other members of the insect community, including beneficial pollinators and other predatory or parasitic insects,” Hermann said.

If that’s the case, farmers and gardeners could have a new toxin-free alternative to conventional pesticides.

“Our next steps will be to trial this strategy in other crops, beyond brassica where we have been using it. An advantage of this research is that lady beetles are predators of a lot of different insect pests, so we may be able to control other insect pests in other crops using this technique as well. The results of these field studies will inform the design of a diffuser that we will develop with an industry partner and guide us toward other field trials that will need to take place before this tool can be made widely available,” Hermann said.

The authors of the new study will present their findings at the fall meeting of the American Chemical Society (ACS), held virtually this week.

Pesticides, parasites, hunger — bees worldwide are dying faster than we thought, other pollinators might be too

Bees are falling like flies, new research reports, and it seems to be due to our use of pesticide cocktails.

Image via Pixabay.

We as a species are virtually completely dependent on bees and other pollinator insects, without whom we wouldn’t be able to put food on the table. A new meta-analysis that reviewed dozens of studies published over the last 20 years reports that the use of pesticide cocktails in agriculture greatly increases mortality among bees, more so than the substances taken individually. This is further exacerbated by the combined effects of agrochemicals, parasites, and malnutrition on bee behaviors and health.

The team concludes that current risk assessments significantly underestimate how much pressure bees and other pollinators are subjected to. The steep drop in pollinator numbers we’ve seen in crop and wild areas is a testament to these pressures, with potentially dire consequences for ecosystems around the world and our food security.

Bees in a pinch

“A failure to address this and to continue to expose bees to multiple anthropogenic stressors within agriculture will result in the continued decline in bees and their pollination services, to the detriment of human and ecosystem health,” the study concluded.

Pollinators, bees included, are the unsung backbone of our agriculture, but also of wild plant life. Given that insect populations are in decline all over the world, this naturally raises concerns for the health of pollinators going forward — and whether they can continue performing their ecological role or not. Roughly 75% of the world’s crops producing fruits and seeds for human consumption, including cocoa, coffee, almonds, and cherries, rely on pollinators.

Such concerns were the starting point for the current study. The authors explain that while bees seem to be able to resist the different stressors plaguing them today taken individually, they’re chafing under their weight taken together. The combined pressure from agrochemicals, parasites, and malnutrition is taking a toll on the species, greatly increasing the likelihood of death for individual bees and hives as a whole.

Intensive agriculture relies on the use of compounds such as fungicides or pesticides to protect crops and ensure large yields. “Interactions between multiple agrochemicals significantly increase bee mortality,” said co-author Harry Siviter, of the University of Texas at Austin. Furthermore, industrial-scale use of managed honey bees (in order to produce honey) increases the species’ exposure to parasites and diseases, which places even more strain on them.

The continued shrinking of areas with wild plants and wildflowers translates to less diverse pollen and nectar sources for bees, and arguably lower overall amounts of food they can access.

Although previous research has looked at these factors independently — including the effect different agrochemicals have on bees — the meta-study is the first one to look at their effect in aggregate. According to the team, the results strongly suggest “that the regulatory process in its current form does not protect bees from the unwanted consequences of complex agrochemical exposure”. Although the current analysis focused on honey bees, as most literature on the subject focuses on them, more research is needed on other pollinators, the team explains, as they might react differently to the stressors we’ve seen here.

Back in 2019, researchers were drawing attention to the fact that almost half of the world’s insect species were in decline, and a third of them were at real risk of going extinct by the end of the century. Leading causes for this decline are pesticide use and habitat destruction. Against that background, the warnings of this meta-study are all the more biting.

The paper “A cocktail of pesticides, parasites and hunger leaves bees down and out” has been published in the journal Nature.

Stormwater could release contaminants to ground and surface water

While giving a sense of cleansing in any city, rainstorms usually cause substances in buildings, streets, and sidewalks to wash off into the drain. This can cause contaminants to end up in ground and surface waters, according to a new study.

Credit: Flickr

Researchers reporting in ACS’ Environmental Science & Technology have analyzed untreated urban stormwater from 50 rainstorms across the US. They found a wide variety of contaminants that could potentially harm aquatic organisms in surface waters and infiltrate groundwater.

Other studies in the past of urban stormwater runoff have revealed a mixture of industrial chemicals, pesticides, pharmaceuticals and other substances that, at certain levels, can be toxic to aquatic life. As a result, many cities and water-management agencies are trying to develop stormwater control measures to keep these contaminants out of other water bodies, such as rivers or aquifers.

However, data from a wide variety of locations across the U.S. are lacking. To help fill this research gap, Jason Masoner and colleagues wanted to catalog and quantify the contaminants in urban stormwater from 50 storm events at 21 sites across the nation.

The team of researchers measured levels of 500 chemical compounds in urban stormwater collected during rainstorms. Samples contained a median of 73 organic chemicals, with pesticides being the most frequently detected chemical group.

Eleven contaminants, including the insect repellent DEET, nicotine, caffeine, and bisphenol A, were found in more than 90% of samples. The researchers also frequently detected prescription and non-prescription pharmaceuticals, indicating that the stormwater was contaminated with human waste, possibly from sewage leaks or other urban sources.

Some of the contaminants were present at levels known to be toxic to aquatic life, but those at lower concentrations could also have effects when combined with all of the other substances in the water.

The study highlighted the need for more research about the long-term effects of these contaminants on aquatic organisms exposed to the stormwater, the researchers said, concluding their paper.

Burkholderia ambifaria. Credit: Genome Portal.

Bacteria might become a natural, toxin-free alternative to pesticides

Burkholderia ambifaria. Credit: Genome Portal.

Burkholderia ambifaria. Credit: Genome Portal.

Man-made pesticides are essential to our modern way of life. They not only protect crops and improve farmers’ yields, but also ward off pests around homes or prevent vegetation from clogging powerlines and highways. Synthetic pesticides also have their downsides, such as their toxicity which can threaten some ecosystems. For instance, the worldwide collapse of bee populations has been at least partly pinned on certain classes of pesticides. This is why some scientists are experimenting with a different kind of pesticides. Instead of toxic chemicals, researchers at Cardiff University are investigating the possibility of using living pesticides — bacteria that protect crops against diseases.

Biopesticides that use bacteria or bacteria-derived substances aren’t exactly new. In the 1990s, the industry experimented with Burkholderia ambifaria bacteria which produce one or more antibiotics that are active against a broad range of plant pathogenic fungi. These antibiotics appear, in many cases, to be important for disease suppression and their use in biocontrol can be an effective substitute for chemical pesticides which may pose risks to human health and the environment. However, their use has been linked with lung infections in people with cystic fibrosis (CF), leading to their withdrawal from the biopesticide market.

Cardiff University researchers, led by Eshwar Mahenthiralingam, want to exploit Burkholderia‘s biopesticide qualities while controlling the adverse effects it might pose the health of some people. For many years, they have been studying Burkholderia-plant interactions in order to find out how they protect plants against diseases.

Researchers sequenced the genome of the bacteria, identifying Burkholderia’s antibiotic-making gene called Cepacin. Subsequent tests showed that the gene protected plants against damping off — a soil-borne fungal disease that affects seeds and new seedlings.

According to Mahenthiralingam, the biopesticide bacteria splits its genomic DNA into 3 fragments, called replicons. By removing the smallest of these 3 replicons, the researchers created a mutant strain which demonstrated effective biopesticidal properties. Experiments with mice show that the mutant strain did not persist in animals with lung infections, suggesting that in the future similar strains could protect our crops without causing health issues.

“Beneficial bacteria such as Burkholderia that have co-evolved naturally with plants, have a key role to play in a sustainable future. We have to understand the risks, mitigate against them and seek a balance that works for all,” said Professor Mahenthiralingam.

“Through our work, we hope to make Burkholderia viable as an effective biopesticide, with the ultimate aim of making agriculture and food production safer, more sustainable, and toxin-free.”

The findings appeared in the journal Nature Microbiology.

Farmer pesticide.

Researchers call for ban on a widely-used pesticide: it impairs brain development

Organophosphates can impair our children’s neurological development — it’s time to ban them, new research says.

Farmer pesticide.

Image via Pixabay.

A team of researchers from the University of California (UC) Davis says there’s enough evidence available to warrant a ban on organophosphates, a widely-used class of pesticides. Prenatal exposure to the compounds put children at risk for neurodevelopmental disorders, they explain, calling for immediate government intervention to phase out these products.


“There is compelling evidence that exposure of pregnant women to very low levels of organophosphate pesticides is associated with lower IQs and difficulties with learning, memory or attention in their children,” said lead author Irva Hertz-Picciotto, professor of public health sciences, director of the UC Davis Environmental Health Sciences Center and researcher with the UC Davis MIND Institute.

“Although a single organophosphate — chlorpyrifos — has been in the national spotlight, our review implicates the entire class of these compounds.”

Organophosphates are very, very good at killing pests. The compounds work by blocking nerve signaling. Essentially, they bind to and inactivate the chemical compound that neurons use to send signals to one another. Today, this pesticide class is used to control insects in a variety of settings — farms, golf courses, even shopping malls and schools.

Given their popularity, environmental levels of organophosphates are quite significant. They’ve been detected in the vast majority of U.S. residents, according to Hertz-Picciotto, who come into contact with the pesticides through food, water, and the air they breathe.

This is a problem, the team explains. There are limits set in place to reduce exposure to organophosphates but it’s not nearly enough. Drawing on over 30 epidemiologic studies, scores of experimental studies with animal models, and cell cultures, they report that prenatal exposure to the chemicals — even at ‘safe’ levels — is associated with poorer cognitive, behavioral and social development.

“It should be no surprise that studies confirm that these chemicals alter brain development, since they were originally designed to adversely affect the central nervous system,” Hertz-Picciotto said.

Part of why these chemicals remain in use — despite recommendations from the U.S. Environmental Protection Agency — may be because low-level, ongoing exposures typically don’t cause visible, short-term clinical symptoms, the team explains. Since people can’t see a definite effect from interacting with these substances, many simply assume they aren’t dangerous, says Hertz-Picciotto.

“Acute poisoning is tragic, of course, however the studies we reviewed suggest that the effects of chronic, low-level exposures on brain functioning persist through childhood and into adolescence and may be lifelong, which also is tragic,” Hertz-Picciotto explained.

Beyond the findings, the team also offers a few recommendations that should help dramatically reduce organophosphate exposure:

  • Removing organophosphates from agricultural and non-agricultural uses and products.
  • Proactively monitoring sources of drinking water for organophosphate levels.
  • Establishing a system for reporting pesticide use and illnesses.

Until a ban is set in place, the team recommends offering medical staff more in-depth education regarding the substance, to help them improve treatment for and patient education on avoiding exposures. They also believe that teaching agricultural workers how to properly handle and apply organophosphate pesticides would help limit exposure — such courses should be held in the workers’ native language, they add. Finally, increasing use of other, less-toxic alternatives should help prepare farmers for an eventual ban.

The paper “Organophosphate exposures during pregnancy and child neurodevelopment: Recommendations for essential policy reforms” has been published in the journal PLOS Medicine.


Glyphosate might be killing bees by messing with their gut bacteria


Credit: Pixabay.

Glyphosate, a broad-spectrum herbicide, has been in wide use since the 1970s with farmers looking to control weeds. Its manufacturer, Monsanto, has always claimed that the chemical only affects plants, being harmless to animals. A new study, however, shows that Glyphosate may be indirectly killing bees by disrupting the microbial community living in their digestive system. As such, the most popular herbicide in the world may be another important factor contributing to the alarming decline in bee populations all over the globe.

“We need better guidelines for glyphosate use, especially regarding bee exposure, because right now the guidelines assume bees are not harmed by the herbicide,” said Erick Motta, a graduate student at the University of Texas Austin, who led the research. “Our study shows that’s not true.”

Glyphosate is a non-selective herbicide, meaning it will kill most plants — including crops and weeds. It works by blocking a specific enzyme, the shikimic acid pathway, which prevents the plant from making key proteins required for growth. The shikimic acid pathway is not found in animals, which is why glyphosate is deemed non-toxic to humans.

However, the enzyme is used by some bacteria. Researchers at the University of Texas in Austin wondered whether glyphosate might be affecting bacteria strains living in the intestines of honey bees (Apis mellifera). They collected 2,000 bees from a hive and fed them sugar syrup dosed with herbicide levels they might encounter in real life.

Three days after they returned to their hives, the glyphosate-exposed bees had fewer Snodgrassella alvi bacteria in their guts than those which were not exposed. Confusingly, the bees that got the highest dose of glyphosate had a microbiome closer to optimal levels compared to bees that received the lowest dose of the herbicide. The researchers say that this may be due to the fact that bees with the highest dose died, leaving behind the resistant variety.

Things become clearer in later tests that showed that glyphosate-laden bees had five times less of the S. alvi bacterium. And when the researchers cultured the bacteria in a petri dish, its growth was very slow or stopped altogether when exposed to a high dose of glyphosate.

Writing in the Proceedings of the National Academy of Sciences, the authors suspect that changes in the bee’s microbiome make the bees more vulnerable to infections. Only 12% of the bees fed with glyphosate survived an infection from Serratia marcescens compared with 47% that were not fed glyphosate. S. marcescens is a bacteria that is widely found in beehives and bee guts that can invade other parts of a bee’s body, leading to lethal infections.

“Studies in humans, bees and other animals have shown that the gut microbiome is a stable community that resists infection by opportunistic invaders,” Moran said. “So if you disrupt the normal, stable community, you are more susceptible to this invasion of pathogens.”

S. alvi lines part of the gut wall and, as such, could act as an insulating layer against the potentially lethal S. marcescens. Additionally, S. alvi also secrets a chemical that can disrupt the invading bacterium.

The findings offer an alternative explanation for the massive decline in bee populations seen all over the world. For instance, beekeepers in the U.S. lost 42.1 percent of their bee colonies in just one year, between April 2014 and April 2015.

“Since the 1980s, honeybees and beekeepers have had to deal with a host of new pathogens from deformed wing virus to nosema fungi, new parasites such as Varroa mites, pests like small hive beetles, nutrition problems from lack of diversity or availability in pollen and nectar sources, and possible sublethal effects of pesticides, ” the USDA notes. But deaths began to spike in the middle of the past decade, when a phenomenon in which bees deserted their hives and died en masse – later named colony collapse disorder – began sweeping hives worldwide. “Commercial keepers were particularly prone to summer losses.”

Previously, scientists have linked colony collapse disorder (CCD) with pesticides, habitat loss, climate change, parasites, stress, and lack of flowers. In this constellation of stressors threatening the most important pollinators on the planet, glyphosate may also pose an important risk.

“It’s not the only thing causing all these bee deaths, but it is definitely something people should worry about because glyphosate is used everywhere,” said Motta.

The findings also raise some important questions about glyphosate’s safety. Perhaps it is affecting the microbiome of other animals, including humans. Previously, the science has been conflicting in its assessment of whether the chemical is carcinogenic or not.

Neonicotinoid pesticides found in 75 percent of honey worldwide

An analysis of honey samples from locations all around the world showed that 75% of them were contaminated with pesticides known to harm bees. About half of the samples actually contained a cocktail of potentially harmful chemicals, besides the neonicotinoid pesticides.

Credit: Pixabay.

Previously, this class of pesticides has been identified by scientists as the most likely cause of colony collapse disorder (CCD) — a strange phenomenon where adult worker honeybees simply disappear from the hives, almost simultaneously, leaving behind the queen and immature bees which could no longer care for themselves. As the name implies, the colony simply collapses.

Honeybees are exposed to this pesticide because its residue is found in nectar and pollen. In fact, it persists in the soil and in woody plants for up to six years after application. While a strong direct link between colony collapse disorder and neonicotinoids has not yet been established, it is increasingly clear that after exposure to these pesticides, honeybees become more susceptible to parasites and pathogens. One study also found that neonicotinoids could prevent the bumblebee queen from laying eggs. Between 2008 and 2013, wild bee diversity in the US dropped by 23 percent, and a previously common bumblebee species was recently listed as endangered.

And it’s not just honeybee populations that are collapsing. Monarch butterflies have been declining significantly, reaching the lowest count ever recorded during the 2013-14 as a result of habitat loss, particularly the loss of milkweed (the species’ only food source), and mortality caused by the use of pesticides. West North America lost 95% of its Monarch butterflies over the last 35 years, according to a distressing recent report.

The long arm of pesticides

Since the first episodes were identified in 2006, CCD has turned into an environmental crisis. Today, most bee species are in decline, with annual regional losses as high as 60%. Bees are some of the world’s most important pollinators, being responsible for about one-third of the plant we eat — a service worth hundreds of billions in the worldwide economy.

The ecological contribution of bees is of course invaluable. Countless species of plants and the animals that feed upon these plants depend on bee pollination for their survival. Where bees disappear, ecosystems are impacted in a cascading effect which is difficult to predict. One thing’s for sure: things aren’t good, and they’re not likely to get better, new research shows.

A new study published in the journal Science joins a body of evidence that suggests pesticides are dramatically interfering with bee foraging and pollination. The international team of researchers analyzed honey samples from nearly 200 hives spread throughout the world. The samples were collected and donated by citizen scientists as part of a project launched by the Botanical Garden of Neuchâtel, Switzerland, in 2016.

“Finding neonicotinoids in honey is perhaps not surprising,” says lead author Christopher Connolly of the University of Dundee, UK. After all, the pesticides are widely used. “But to find neuroactive levels, in so many samples at many global sites, is shocking.”

About 75% of all samples contained measurable quantities of pesticides, which was surprising given that the coverage also included highly remote locations like oceanic islands. About half of the samples contained a mix of various insecticides.

The concentrations of pesticides involved are very low but these chemicals are extremely toxic, up to 10,000 times more potent than DDT, one of the first pesticides of widespread use. DDT was banned for agricultural uses worldwide by the 2001 Stockholm Convention on Persistent Organic Pollutants. 

The highest contamination rates were reported in North America with 86% of samples containing one or more neonicotinoid pesticides. Asia, Europe, and South America followed, with  80%, 79%, and 57% of samples containing pesticides, respectively. The EU introduced a partial ban on neonicotinoids back in 2013, but the European honey samples included in the analysis was sourced before the legislative measure was installed.

“If you look at the minimum concentration for which a significant negative impact on bees has been found, then 48% of our samples exceed this level,” said Professor Edward Mitchell at the University of Neuchâtel.

Neonicotinoids were introduced the mid-1990s. The group consists of various pesticides that are based on the chemical structure of nicotine, and attack the nervous systems of insect pests. But bees, wasps, butterflies, and other insect pollinators seem to have been caught in the cross-fire.

According to a 2014 review, neonicotinoids might seriously jeopardize worldwide food security with far-reaching consequences. Three types of pesticides in this class have been banned in the EU for flowering plants, and the appropriate EU commission is now working on a draft that will ban neonicotinoids from all plants. Other countries will surely follow, hopefully with a worldwide ban similar to DDT — for everyone’s sake.

Popular pesticides are killing of bumblebees by preventing them from laying eggs

More and more studies add evidence to a bleak theory: our pesticides are killing off the bees.

bee bumblebee pesticide

The Buff-tailed bumblebee (Bombus terrestris). Image credits: Alvesgaspar.

Pesticides vs bees

Bumblebees don’t get nearly as much love as honey bees, but maybe they should. Sure they’re wild and they don’t produce as much honey as their “domestic” counterparts, but they help pollinate numerous fruits, vegetables, and wildflowers. Bumblebee species are declining in Europe, North America, and Asia due to a number of factors — including habitat degradation, pathogens, and pesticide use. Now, a new study analyzed the latter factor, focusing on popular pesticides called neonicotinoids, and what they found isn’t pretty, as NPR puts it. The pesticides apparently deter bumblebee queens from laying eggs.

Neonicotinoids are a relatively new class of insecticides that emerged in the 1990s. Compared to some of their predecessors, they cause less toxicity in birds and mammals. However, in recent years, they’ve come under increasing scrutiny due to their environmental impact, especially on bees and other benign insects. Neonics (as they’re also called) are systemic and move throughout growing plants. This means that traces of the pesticide reach the pollen, which the bees consume. Quite often, neonics have been found in areas that haven’t been treated, such as meadows or wildflower patches.

Because they spread so much, the impact they have on bees is far reaching and hard to thoroughly assess — yet a growing number of studies associated these pesticides with honeybee colony collapse disorder (CCD) and loss of birds due to a reduction in insect populations. While these findings remain controversial, in 2013, the European Union (and some other non-EU countries) banned the use of such pesticides, and positive results were visible fast. The ban is only temporary for now, but the EU is considering making it permanent despite complaints from pesticide companies and some farmers which claim yields have gone down.

For most of the world, neonics are still going strong, and both bees and bumblebees are paying a huge price.

Bumbling around

For the study, researchers from the Royal Holloway University of London set up an experiment involving bumblebee queens. They fed the queens a syrup which contained traces of a neonicotinoid called thiamethoxam, similarly to what a queen would be exposed to in real life.

bee bumblebee pesticides

Honeybees and bumblebees are threatened by neonicotinoids alike. Image credits: Jon Sullivan.

These queens were 26% less likely to lay eggs when they were exposed to thiamethoxam. This isn’t saying that the population would only decline by 26% — but when they modeled the impact of this 26% decrease, they found a significantly increased likelihood of population extinction.

“Without the queen laying eggs, there is no colony,” says Nigel Raine, one of the scientists who conducted the experiment. Raine helped start the experiment, but has since moved to the University of Guelph in Canada.

The problem is that the pesticide exposure is impacting bumblebee populations in conjunction with other factors, such as inadequate resources or pathogens. It’s difficult to say just how much of an effect all these stresses working together will have, but so far, it seems to be devastating.

Bumblebees are in danger in many developed countries and it’s becoming clearer and clearer that pesticides are at least partly to blame.

“Bees play a vital role as pollinators in both agricultural and natural systems. However, there is increasing concern about the state of wild bee populations. Nearly 10% of European bee species are currently considered threatened and bumblebees are declining on a global scale. The cause of these declines is thought to be a combination of factors, particularly habitat loss, parasites and diseases, invasive species, and climate change,” researchers conclude.

Journal Reference: Gemma L. Baron, Vincent A. A. Jansen, Mark J. F. Brown & Nigel E. Raine — Pesticide reduces bumblebee colony initiation and increases probability of population extinction. doi:10.1038/s41559-017-0260-1

Farms could slash pesticide use without losing any yield or money, new study finds

Virtually all types of farms could cut pesticide use while still producing just as much food, and potentially even save money, a surprising new study found.

Image via Wikipedia.

The pesticide industry has grown side by side global agriculture, with most farmers today not even imagining farming without pesticides. A recent report released by the UN cast a big shadow on the necessity of pesticide usage, calling it ‘a myth’ supported by ‘aggressive and unethical marketing.’ Then, the UN reported that pesticides do a great deal of harm to the planet and ‘using pesticides has nothing to do with getting rid of hunger.’ That idea seems to be backed by a new research, whose authors analyzed the pesticide use, productivity, and profitability of almost 1,000 farms of all types across France.

Their conclusions are stunning: 78% of farms would be just as profitable or even more profitable if they reduced pesticide consumption. When it comes to insecticides, it gets even better: 94% of farms would lose no production if they cut insecticides, while 40% would actually produce more.

“It is striking,” said Nicolas Munier-Jolain, at France’s National Institute for Agricultural Research, and one of the team who conducted the new study. He said the results show that pesticide reduction is possible today for most arable farmers, without losing money: “Our results are quite consistent with the UN report.”

Munier-Jolain says that many farmers want to reduce or replace pesticides, but they don’t have much information available — in fact, most of the information they have comes from pesticide producers or distributors, who obviously have no interest in downplaying their products.

However, this doesn’t mean that pesticides should simply be eliminated and everything will be fine, no one is saying that. What the team suggests is employing other measures such as rotating crops, mechanical weeding, using resistant varieties, and carefully managing sowing dates and fertilizer use. He believes that only when the farmers will be truly informed about their options will we be able to truly make a difference.

“If you want real reduction in pesticide use, give the farmers the information about how to replace them,” said Munier-Jolain. “This is absolutely not the case at the moment. A large proportion of advice is provided by organisations that are both selling the pesticides and collecting the crops. I am not sure the main concern of these organisations is to reduce the amount of pesticide used.”

So far, that’s not really happening. Take France for example, where a 50% reduction in national pesticide use was scheduled for 2018 and was delayed for 2025. Right now, usage is increasing instead of decreasing. In the US, EPA administrator Scott Pruitt refused to ban one of the most dangerous pesticides (chlorpyrifos), a measure that had been set in motion for years. Globally, it seems that the world is using more pesticides instead of less, and that’s a highly worrying trend. The good news is that the study concluded that farms which were using more pesticides had more potential for reducing their usage without any negative consequences.

The results of the study seem backed by some practical evidence as well. Sweden, for instance, has reduced much of its pesticide consumption with yields remaining constant, as have many rice farmers in Indonesia, with similar results. We also know that pests are developing more and more pesticide resistance, an issue which is causing more and more losses every year.

If this study stands true, it could make a big difference. The reduction of pesticide use is one of the critical drivers to preserve the environment and human health. Many of the chemicals used in pesticides are persistent soil contaminants, whose impact may endure for decades and adversely affect the entire ecosystem from the bottom-up: the soil, the plants which live in the soil, the animals which eat the plants, and so on. For humans, pesticides can cause both acute and long-lasting health issues. Direct exposure to pesticides is extremely dangerous, while pesticide runoff can create long-lasting environmental problems.

Journal Reference: Martin Lechenet, Fabrice Dessaint, Guillaume Py, David Makowski and Nicolas Munier-Jolain — Reducing pesticide use while preserving crop productivity and profitability on arable farms.

UN scientists denounce ‘myth’ that we need pesticides to feed the world

Image credits: jetsandzeppelins.

A surprising report from the UN warns of the catastrophic consequences pesticides can have (and are already having) on the world. The report claims that due to ‘systematic denial of harms’ and ‘unethical marketing tactics’ pesticide usage is doing more harm than good and the idea that we need pesticides to feed the world is a myth.

“Defined as any substance or mixture of substances of chemical and biological ingredients intended to repel, destroy or control any pest or regulate plant growth, pesticides are responsible for an estimated 200,000 acute poisoning deaths each year, 99 per cent of which occur in developing countries, where health, safety and environmental regulations are weaker and less strictly applied,” the report starts out. “Despite the harms associated with excessive and unsafe pesticide practices, it is commonly argued that intensive industrial agriculture, which is heavily reliant on pesticide inputs, is necessary to increase yields to feed a growing world population, particularly in the light of negative climate change impacts and global scarcity of farmlands.”

Feeding the world

The world’s population is set to reach 9 billion in 2050 and over 11 billion by 2100. Add in water scarcity in many parts of the world and continuous stress exerted by climate change and you end up with a recipe for disaster. Indeed, we’re struggling to feed the world as it is, any growing pressure could lead to a catastrophic cascading effect.

The new report, which is co-authored by Baskut Tuncak, a UN special rapporteur, seriously bashes the use of pesticide and pesticide companies. Tuncak comments:

“While scientific research confirms the adverse effects of pesticides, proving a definitive link between exposure and human diseases or conditions or harm to the ecosystem presents a considerable challenge. This challenge has been exacerbated by a systematic denial, fuelled by the pesticide and agro-industry, of the magnitude of the damage inflicted by these chemicals, and aggressive, unethical marketing tactics.”

However, we can’t really give up on pesticides — and no one’s saying we should throw them out the window — but there are other aspects to consider, just as vital to our global food security. For starters, Hilal Elver, the UN’s special rapporteur on the right to food, says that much of the world’s crops are not being used to feed the people, but rather to support cheaper products in the developed world. Commodity products such as soy (often used to feed animals) and palm oil (used in everything from pastry to pre-cooked meals) are taking the place of other plants, which could be used to feed local communities. This, says Elver, is the main blame of the corporations:

“The corporations are not dealing with world hunger, they are dealing with more agricultural activity on large scales.”

Pesticide application for chemical control of nematodes in a sunflower planted field. Karaisalı,, Turkey. Image credits: Zeynel Cebeci.

A myth, or a necessary evil?

Elver says that we don’t need pesticides to feed the world, we can do jus as fine without them. The main problems to tackle, she adds, are inequality and a lack of proper food distribution.

“Using more pesticides is nothing to do with getting rid of hunger. According to the UN Food and Agriculture Organisation (FAO), we are able to feed 9 billion people today. Production is definitely increasing, but the problem is poverty, inequality and distribution.”

But not everyone agrees. There’s a reason why virtually the entire world uses pesticides, and that’s a very pragmatic reason: whether we like it or not, pesticides get a lot of work done.

“The claim that it is a myth that farmers need pesticides to meet the challenge of feeding 7 billion people simply doesn’t stand up to scrutiny,” said a spokesman for the Crop Protection Association, which represents pesticide manufacturers in the UK. “The UN FAO is clear on this – without crop protection tools, farmers could lose as much as 80% of their harvests to damaging insects, weeds and plant disease.”

The spokesperson did agree that there’s a lot of work to be done but emphasized that pesticides are still required for global food security.

“The plant science industry strongly agrees with the UN special rapporteurs that the right to food must extend to every global citizen, and that all citizens have a right to food that has been produced in a way that is safe for human health and for the environment,” said the spokesman. “Pesticides play a key role in ensuring we have access to a healthy, safe, affordable and reliable food supply.”

What we need

At the end of the day, the UN raised a big red flag, but is this really going to make a difference? I’m not sure. It is indeed a myth that pesticides in their current form are required to feed the world but in that case, we do need to invest in alternative forms of pest control — and since most people are not too fond of GMOs, it’s not clear what that alternative is. However, I do hope this report puts a lot of heat on both companies working with pesticides and states. The EU, for example, has much stricter laws on pesticides than most of the world, and is generally able to enforce them — and they’re reaping the rewards. I think the report’s more moderate conclusion is on point:

“It is time to create a global process to transition toward safer and healthier food and agricultural production.”


Bees get much needed win as US court rules against neonicotinoid pesticide

It’s been a very rough period for bees. Bee numbers have been dropping at alarming rates, and the growing consensus seem to be that only limiting pesticide use (especially for some pesticides) can save them. Now, a US court overturned federal approval for a new formulation called sulfoxaflor, basically banning the pesticide.

Pesticides killing bees

Image via Discover Magazine.

The main problem is with neonicotinoids – a class of neuro-active substances linked with a swarm of negative environmental effects, including honey-bee colony collapse disorder (CCD) and loss of birds due to a reduction in insect populations. Sulfoxaflor is a neonicotinoid; on May 6, 2013, the United States Environmental Protection Agency approved the first two commercial pesticide products that contain sulfoxaflor, marketed under the brand names “Transform” and “Closer”, to the Dow Chemical Corporation. However, the decision was appealed and now, the U.S. 9th Circuit Court of Appeals issued a ruling overturning the EPA’s approval of sulfoxaflor, finding that the EPA had relied on “flawed and limited” data, and its green light was unjustified given the “precariousness of bee populations”.

Circuit judge Randy Smith said:

“I am inclined to believe the EPA… decided to register sulfoxaflor unconditionally in response to public pressure for the product and attempted to support its decision retrospectively with studies it had previously found inadequate.”

This decision can also be appealed.

Neonicotinoids have grown popular for protecting crops and orchards from unwanted pests, but in recent years, there has been increasing evidence that they also damage pollinators and disrupt their navigation systems, with major impacts worldwide.

Neonicotinoid pesticides can disrupt bee navigation (Image: Zhang Bo/Getty)

Striking contradictions

The strange thing about the legality of neonicotinoids is that the European Union banned most of them in 2013, as part of an effort to protect bees. An even larger investigation on banning more pesticides will be launched this autumn. However, last month, the EU approved the use of sulfoxaflor, while leaving final decisions on its use to national regulators, despite the European Food Standards Authority warning that “missing information” about sulfoxaflor meant that “a high risk to bees was not excluded”. Meanwhile, in the US, most neonicotinoids are still allowed for use, but sulfoxaflor has been banned. This creates a lot of confusion and misunderstanding.

“The public will be justifiably confused and concerned,” says Matt Shardlow, CEO of Buglife, a British group that campaigns against neonicotinoids.

Answering Questions

The lead attorney on the above mentioned lawsuit challenging the EPA’s approval of the pesticide sulfoxaflor took the time to answer some questions on Reddit. Here are some of the most interesting insights:

Question: What can the average person do to help bees?

Answer: First off, when buying ornamental plants for your home garden, make sure that they don’t come pre-treated with neonics. Unfortunately, many big nurseries are still selling flowers that are sprayed with neonics.

Q: Why do you have to say in response the NPR article basically saying everything is fine and the numbers reported don’t really tell the story at all?

A: First, we cannot expect native pollinators to stand in for commercially kept honeybees. Native bees are great, but where are we going to find the 1.5 million colonies it takes just to pollinate California’s almond crop each January? Second, every indication is that native bees have been taking it in the ear as well, and that’s a huge environmental impact in its own right.

Q: Thanks a lot for fighting the good fight, my question is how much other stuff needs to be removed to save bees in your opinion?

A: The hope is that we will eventually find a way to get off the toxic treadmill of evermore reliance on pesticides. It’s a social change, and it’s not going to happen on its own. It’s going to take commitment and real action on the part of government, corporate America, and all of us.

Q: What is going to replace neonicotinoids? Is the alternative better or worse for bees and farmers?

The hope is that we will eventually find a way to get off the toxic treadmill of evermore reliance on pesticides. It’s a social change, and it’s not going to happen on its own. It’s going to take commitment and real action on the part of government, corporate America, and all of us.

Q: What do you think will really happen if bees go extinct?

A: The reality is that commercial beekeepers will go extinct (read, bankrupt) long before honeybees. But the impact on agriculture and our diet will be essentially the same, because many of our most important crops absolutely require commercially kept bees for pollination. Agriculture as we know it just wouldn’t be possible without commercial beekeepers.


Monarch butterfly populations went down 80% in 21 years

A new study has found that monarch butterfly populations have dwindled at alarming rates in the past couple of decades, dropping on average by 80%. In the forests of Mexico, they went down by as much as 90%.


The monarch butterfly (Danaus plexippus) is known for its annual southward migration from Canada and the US to Mexico, which takes several generation. Usually, the initial populations overwinter in various coastal sites in central and southern California. The overwintered population of those east of the Rockies may reach as far north as Texas and Oklahoma during the spring migration. The second, third and fourth generations return to their northern locations in the United States and Canada in the spring.

However, in recent times, their populations have been going down dramatically – and the main cause, as usually, is us – our pesticide use, to be more precise.

The main food source of these butterflies is milkweed, also an important nectar source for native bees, wasps, and other nectar-seeking insects. The increasing usage of pesticides for agriculture has led to a decline in milkweed habitats.

“A monarch that leaves its wintering grounds in Mexico will never make it to Vermont,” said Mark Ferguson, a biologist with the Vermont Fish and Wildlife Department, in an interview with The Boston Globe. “Instead, several generations are born and die along the way, meaning that the grandchildren or great-grandchildren of the monarchs leaving Mexico eventually arrive in Vermont each summer. Because monarchs need milkweed to reproduce, anything we can do in Vermont to promote this vitally important species will help monarchs thrive.”

Ferguson believes that Vermont will play a key role in the future of monarchs, because its meadows and old fields provide habitat for milkweed. This means that if officials support the re-expansion of milkweed, the butterflies could be saved. Ferguson has recommended that people should limit the use of insecticides and herbicides to the strict necessary.

Bonus Fact: Monarchs are foul-tasting and poisonous due to the presence of a specific type of steroids in their bodies, which the caterpillars ingest as they feed on milkweed.

Italian ban on pesticides has major benefits on bee health


In case you didn’t know, bee popullations all around the world are dwindling. The disorder which is causing this massive decline in bee numbers is called CCD – colony collapse disorder. In 2012 alone, a phenomenon called colony collapse disorder (CCD) wiped out about half of honeybee hives [read more here]. What happens in CCD is that basically worker bees go away from the hive and never return; it’s not yet clear why this happens and what are the exat causes, but there is a strong link with the more intensive use of pesticides.

The pesticide industry is huge however, and, naturally, they started voicing skepticism about this – things reached a critical level when Italy announced the ban on some pesticides last year. But the ban passed, a year passed after it, and now we see the results.


The status of the bee popullations has improved dramatically. Francesco Panella, President of the Italian Association of Beekepers, says:

On behalf of beegrowers working in a countryside dominated by maize crops, I wrote to the Minister of Agriculture to confirm the great news, for once: thanks to the suspension of the bee-killing seed coating, the hives in the Po Valley are flourishing again. We cannot underestimate that there are over one million hectares of maize crops, predominantly in Northern Italy, which means one crop out of every seven which are grown every year in our country. This year’s magnificent and unusual spring growth of bee colonies means a very good production of acacia honey in Northern Italy. We are now anxious to ensure that the temporary ban of neonicotinoid seed coating becomes definitive

There have been three papers on the matter, each detailing a different type of pesticide, though none of them are peer reviewed. However, Marco Lodesani, director of the honey bee and silkworm unit at the Agricultural Research Council (CRA-API) in Bologna, elaborates:

What did we learn in the past few years about the causes of CCD and the link with neonicotinoids?

Until recently, studies focused on the immediate, lethal effects of pesticides on bees. In other words, they looked at the dose that is needed to kill bees if they are exposed to a certain insecticide.

However, it is now clear that sub-lethal doses have a chronic effect that may be even more critical. When bees fly over the dust from coated seeds, they accumulate small doses of neonicotinoids that do not kill them. But it affects both each individual and the colonies in more subtle, long-term ways. For example, contaminated bees have a weaker immune response. This makes them more susceptible to viruses, which are a major cause of death.

Other effects are neurological and include learning problems, impaired orientation, or the inability to remember colours and odours. All of these aspects are crucial for the social organisation of colonies.

Are these chronic effect taken into account by the industry when testing for the safety of new compounds?

Not really. Testing is largely based on assays that look at the acute toxicity of compounds. But with CCD you do not necessarily expect to see bees decimated right in places where they use pesticides. You need to look at sub-lethal effects that are more insidious and difficult to study, but still involve entire colonies.

Via Planet3