Beyond Pesticides (October 17, 2024) On September 30, 2024, the U.S. Environmental Protection Agency (EPA) opened a public comment period about production of specific per- and polyfluoroalkyl substances (PFAS, also known as ‘forever chemicals’)—including perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA). EPA is collecting information on the fluorination process of high-density polyethylene (HDPE) and other plastic containers to inform possible regulatory action under the Toxic Substances Control Act (TSCA). The deadline for submitting comments is November 29, 2024. PFOA and twelve other PFAS compounds are created during the fluorination of HDPE plastic containers by Inhance Technologies, LLC, the only U.S. company manufacturing containers using this fluorination technique (see here). Studies by EPA, independent researchers, and the company itself demonstrate that PFAS leaches from container walls into contents, exposing millions to these toxic chemicals without their knowledge. EPA notes, “Long-chain PFAS like PFOA, PFNA, and PFDA build up in our bodies and the environment over time. Even small amounts can significantly contribute to people’s long-term exposure and health risk for cancers, impacts to the liver and heart, and immune and developmental damage to infants and children.” The adverse effects of PFAS exposure are linked to serious health issues, […]

(Beyond Pesticides, September 13, 2024) While chemical companies persist in pushing simplistic solutions to complex problems, there is a large amount of evidence that organic farming presents effective solutions to many of those problems. Now there is new evidence that organic agriculture prevents the untold harms of pesticide-driven monoculture. In a new study, German researchers compared 16 agricultural landscapes in Lower Saxony and northern Hesse that had different combinations of semi-natural habitat, organic practices, and annual and perennial flower strips. Overall, the researchers find that organic farming provides the highest benefit to the bees, along with the presence of diverse flowering plants in and near monoculture fields. The study compares the effects of three honey bee conservation methods on the prevalence of the parasitic mite Varroa destructor and the 11 parasites Varroa transfers to bees, and the impact of these destructive organisms on bee colony growth. The findings were reported in the June issue of the Journal of Applied Ecology. Organic practices lead directly to lower parasite load and higher colony growth—essentially, the more organic crops, the more bees, and the more parasites, the fewer bees. Pesticides plus monoculture doubles the damage: Pesticides increase mortality, damage bees’ immune systems, and […]

(Beyond Pesticides, July 16, 2024) Yet another study in the August 2024 journal Ecotoxicology and Environmental Safety has found that exposure to organophosphorus pesticides (OPPs) is correlated with increased suicidal thoughts in some people. This study is just the latest in a long line of studies from around the world that have linked pesticide exposure to mental health conditions, including sleep disorders, depression, and suicidal ideation (SI). As the rate of suicide increased by 30% between 2000 and 2020, there is an urgent public health need to investigate and address all potential contributing factors. A 2019 study, covered in Daily News, found that teens and adolescents living in agricultural areas and exposed to organophosphate (OP) insecticides are at higher risk of depression, In July and January this year, other studies link farmer psychiatric episodes to pesticide exposure, adding to the body of science. Exposure to household pesticides is also linked to depression in a 2020 study.   Study and Methodology  The study entitled “Association between exposure to organophosphorus pesticide and suicidal ideation among U.S. adults: A population-based study,” analyzes information on the mental and physical health of over 5,000 individuals aged 20 and up in the United States. The study aims […]

(Beyond Pesticides, July 10, 2024) An article last month in Entomology Today, a publication of the Entomological Society of America, highlights the important findings of a study published earlier this year in the Journal of Insect Science. While there has been debate on whether neonicotinoid (neonic) insecticides or Varroa mites (Varroa destructor) are more detrimental to the survival of bees, evidence suggests that neonicotinoids are not only harmful individually but can increase vulnerability to parasitism from mites in western honey bees (Apis mellifera). The Entomology Today article reads: “Some researchers and organizations have pointed to neonics as directly harming bees. Others have pointed to other issues, like Varroa mite infestation, as more hazardous to honey bee populations.” There is scientific evidence supporting each claim, as both cause stress to bee species that can lead to population decline. The study in the Journal of Science, however, is “the first experimental field demonstration of how neonicotinoid exposure can increase V. destructor populations in honey bees and also demonstrates that colony genetic diversity cannot mitigate the effects of neonicotinoid pesticides.”  As the article states, “The researchers were not looking for impacts on Varroa mites at first. Instead, they were looking to understand how […]

(Beyond Pesticides, June 13, 2024) A study published in Conservation Letters, a journal of the Society for Conservation Biology, exposes critical shortcomings in the U.S. Environmental Protection Agency’s (EPA) ecological risk assessment (ERA) process for modeling the risks that pesticides pose to bees and other pollinators. For the study, “Risk assessments underestimate threat of pesticides to wild bees,” researchers conducted a meta-analysis of toxicity data in EPA’s ECOTOX knowledgebase (ECOTOX), an EPA-hosted, publicly available resource with information on adverse effects of single chemical stressors to certain aquatic and terrestrial species. The meta-analysis found that the agency’s approach, which relies heavily on honey bee data from controlled laboratory studies, drastically underestimates the real-world threats from neonicotinoid insecticides (and likely other pesticides) to native bees and other pollinators. The study “challenges the reliability of surrogate species as predictors when extrapolating pesticide toxicity data to wild pollinators and recommends solutions to address the (a)biotic interactions occurring in nature that make such extrapolations unreliable in the ERA process.” Beyond Pesticides executive director Jay Feldman remarked, “EPA’s ecological risk assessment process is fundamentally flawed and puts thousands of bee species at risk of pesticide-caused population declines and extinctions.” Mr. Feldman continued, “This underscores the urgent […]

(Beyond Pesticides, April 24, 2024) On April 16, 2024, the U.S. Environmental Protection Agency (EPA) posted an “update” to the Draft Herbicide Strategy Framework (Draft Herbicide Strategy Framework to Reduce Exposure of Federally Listed Endangered and Threatened Species and Designated Critical Habitats from the Use of Conventional Agricultural Herbicides) that was released last summer, weakening aspects of the agency’s efforts to “protect” endangered species from herbicide use. The update outlines three types of modifications to the Draft Strategy, including “simplifying” its approach, increasing growers’ “flexibility” when applying mitigation measures, and reducing the mitigation measures required in certain situations. By reducing the stringency of the Strategy, advocates are again questioning EPA’s commitment to fulfilling legal requirements under the Endangered Species Act (ESA) or protecting endangered species and their habitats in the midst of an unprecedented rate of global extinction. ESA is celebrated as one of the most far-reaching conservation laws globally, credited with preventing the extinction of 99 percent of those species the government targets for protection, according to the U.S. Fish and Wildlife Service (USFWS). ESA establishes a framework to categorize species as “endangered” or “threatened,” granting them specific protections. Under ESA, EPA is required to consult with relevant agencies […]

(Beyond Pesticides, December 12, 2023) A review published in Nature Reviews Microbiology finds pesticides can disrupt honeybee (Apis mellifera) microbiota (bacteria) in their gut, altering the immune system, metabolism, behavior, and development. Many studies emphasize chemical-driven agricultural systems dependent upon pollinators and products that harm or kill off these sensitive species. Previous studies have linked adverse impacts to bee microbiome to pesticide exposure. Toxic (manufactured poison) pesticides readily contaminate the ecosystem with residues pervasive in food and water commodities. In addition to this study, the scientific literature commonly associates pesticides with human, biotic, and ecosystem harm, as a doubling of toxic effects on invertebrates, like pollinators, has been recorded since 2004.  Pollinator declines directly affect the environment, society, and the economy. Many agricultural and nonagricultural plant species will decline or cease to exist without pollinators. In turn, the economy will take a hit, since much of the economy (65%) depends upon the strength of the agricultural sector. As the science shows, pesticides are one of the most significant stressors for pollinators. Additionally, pesticides have a devastating impact on bees and other pollinators and the larger context of what has been called by scientists as the “insect apocalypse.” In a world where habitat loss and fragmentation show no sign […]

(Beyond Pesticides, September 13, 2023) A study published in Global Change Biology finds climate change increases bees’ sensitivity to pesticide exposure, impairing the pollinators’ ability to respond to light (Ultra-Violet [UV] stimuli), reducing floral syrup consumption, and lessening longevity (length of life) up to 70 percent. Notably, the reduction in floral syrup consumption indicates nutritional stress that further impacts bee species’ fecundity (productiveness), driving bee declines. Unless more is done to combat the climate crisis, the current global warming scenario increasing bees’ sensitivity to pesticide exposure will continue to threaten all pollinator health. The pervasiveness of pesticide exposure, combined with climate change, threatens global species biodiversity. As has been widely reported, pollinators (such as bees, monarch butterflies, and bats) are a bellwether for environmental stress as individuals and as colonies. Pesticides intensify pollinators’ vulnerability to health risks (such as pathogens and parasites), with pesticide-contaminated conditions limiting colony productivity, growth, and survival. The globe is currently going through the Holocene Extinction, Earth’s 6th mass extinction, with one million species of plants and animals at risk, including pollinators. Pollinator declines directly affect the environment, society, and the economy. Without pollinators, many agricultural and nonagricultural plant species will decline or cease to exist as U.S. pollinator declines, particularly […]

(Beyond Pesticides, August 29, 2023) A study published in Insect Biochemistry and Molecular Biology finds the widely used azole fungicide, tebuconazole, has damaging impacts on the redox homeostasis (the process of maintaining balance between oxidizing and reducing reactions) and fatty acid composition in honey bees’ brain via oxidative stress. Acute, field-realistic sublethal exposure to tebuconazole decreased the brain’s antioxidant capacity, key antioxidant defense systems, and oxidative degradation and alteration of lipids (fats) in the brain. Thus, this study adds to the scientific literature on the adverse effects of chemical exposure on pollinator health, especially in sublethal concentrations. Degenerating cognitive skills can threaten honey bee survivability, decreasing colony fitness and individual foraging success. Much research attributes the decline of insect pollinators (e.g., commercial and wild bees and monarch butterflies) over the last several decades to the interaction of multiple environmental stressors, from climate change to pesticide use, disease, habitat destruction, and other factors. Pollinator declines directly affect the environment, society, and the economy. Without pollinators, many plant species, both agricultural and nonagricultural, will decline or cease to exist, as U.S. pollinator declines, particularly among native wild bees, depress crop yields. In turn, the economy will take a hit, since much of the economy (65%) depends upon the […]

(Beyond Pesticides, May 9, 2022) The Colorado legislature last week passed SB23-266, a bill limiting the use of bee-toxic neonicotinoid pesticides in the state. The news comes as other states consider their own restrictions, and the U.S. Environmental Protection Agency (EPA) is publishing details on exactly which endangered species are set to be harmed by the ongoing use of these harmful insecticides. This latest news shows that protecting pollinators is possible, and urgently needed given growing understanding of the dangers these chemicals pose to the most vulnerable wildlife in the country.   The Colorado bill requires the state’s commissioner of agriculture to adopt rules designating neonicotinoid pesticides as ‘limited-use’ pesticides in the state. With this designation, only licensed pesticide dealers may sell products containing these chemicals. Per the state’s legal code, the “limited-use” designation means the same as a federal “restricted-use” pesticide, which permits sales and use only for certified applicators. Passage of this bill marks an important step forward for pollinator protection efforts in the state. It will help ensure that homeowners are not able to easily purchase this product at big box retailers, but will allow continued use in residential areas and in agriculture. Colorado’s bill fulfills guidance […]

(Beyond Pesticides, April 6, 2023) A study published in Global Change Biology adds to research demonstrating that climate change can exacerbate the adverse impacts of pesticide exposure on managed and wild bees. Temperature can alter the sublethal effect pesticides, particularly the neonicotinoid (neonic) imidacloprid and the sulfoximine sulfoxaflor, have on bumble bee behavior tied to fitness and pollination services. Both an increase and decrease in temperature can cause diverging thermal responses in bumble bee behavior. However, increasing temperature bares more severe behavior abnormalities than cooler temperatures. The pervasiveness of pesticide exposure combined with climate change threatens global species biodiversity. As has been widely reported, pollinators (such as bees, monarch butterflies, and bats) are a bellwether for environmental stress as individuals and as colonies. Pesticides intensify pollinators’ vulnerability to health risks (such as pathogens and parasites), with pesticide-contaminated conditions limiting colony productivity, growth, and survival. Now more than ever, people are changing their sentiment toward sustainability, with two-thirds of consumers stating the importance of limiting climate change impacts and 88 percent supporting greater pollution reduction. The globe is currently going through the Holocene Extinction, Earth’s 6th mass extinction, with one million species of plants and animals at risk. With the increasing rate of biodiversity loss, advocates say it is essential for […]

(Beyond Pesticides, February 1, 2023) Honey bee declines in the United States are “primarily related” to pesticide exposure, parasitic mites, and extreme weather conditions, research published by Penn State scientists have determined. Publishing the results in Scientific Reports, the researchers aim to provide a national overview of the range of factors harming bee colonies. “Some previous studies have explored several potential stressors related to colony loss in a detailed way but are limited to narrow, regional areas,” said study co-author Luca Insolia, PhD. “The one study that we know of at the national level in the United States explored only a single potential stressor. For this study, we integrated many large datasets at different spatial and temporal resolutions and used new, sophisticated statistical methods to assess several potential stressors associated with colony collapse across the U.S.” The results reinforce calls from bee health advocates in the U.S. and around the world: eliminate toxic pesticide use, the lowest hanging fruit contributing to pollinator declines. In order to create a more comprehensive national overview, geographers, entomologists, and statisticians all participated in the study, reviewing publicly available data on colony health, land use, weather, and other environmental factors over a five-year period from […]

(Beyond Pesticides, January 18, 2023) Sunflower plantings have the potential to significantly reduce mite infestations in nearby honey bee colonies, according to research recently published in the Journal of Economic Entomology by researchers with the U.S. Department of Agriculture (USDA). With pollinators under threat from pesticides, climate change, loss of habitat, and the spread of disease and parasites, sustainable methods that address multiple factors at once are needed. This study points to a way to address destructive Varroa mites, while reducing the need for in-hive use of miticides that can likewise harm colony health. “If sunflowers are as big of a factor in mite infestation as indicated by our landscape-level correlations … having a few more acres of sunflower within a mile or two of apiaries could bring colonies below the infestation levels that require treatment of hives with acaracides (i.e., mite-controlling chemicals),” said lead author Evan Palmer-Young, PhD, of USDA’s Bee Research Lab in Beltsville, MD. Prior research has pointed to sunflower pollen as a potential benefit for a number of common bee diseases and infestations, including the Varroa mite, the fungal parasites Nosema spp, and various viruses. Investigations went through four different experiments aimed at characterizing any potential […]

(Beyond Pesticide, October 20,2022) Exposure to environmentally relevant levels of glyphosate-based herbicides (GBHs) weakens bumblebees’ (Bombus Terrestris) ability to distinguish between colors or fine-color discrimination. According to research published in Science of The Total Environment, a lack of fine-color discrimination skills can threaten bumble bee survivability through impact on colony fitness and individual foraging success. Much research attributes the decline of insect pollinators (e.g., commercial and wild bees and monarch butterflies) over the last several decades to the interaction of multiple environmental stressors, from climate change to pesticide use, disease, habitat destruction, and other factors. In the U.S., an increasing number of pollinators, including the American bumblebee and monarch butterfly, are being added or in consideration for listing under the Endangered Species Act, with specific chemical classes like systemic neonicotinoid insecticides putting 89% or more of U.S. endangered species at risk. Pollinator decline directly affects the environment, society, and the economy. Without pollinators, many plant species, both agricultural and nonagricultural, will decline or cease to exist as U.S. pollinator declines, particularly among native wild bees, limits crop yields. In turn, the economy will take a hit, as much of the economy (65%) depends upon the strength of the agricultural sector. As science shows, pesticides are one of the most significant stressors […]

(Beyond Pesticides, September 13, 2022) Every store-bought milkweed sample tested in a recent study contains multiple toxic pesticides, placing monarchs reliant on these plants in harm’s way at a time the species can ill afford any further loss to its population. Pollinator declines have influenced many residents throughout the U.S. to take action into their own hands and transform their home yards or businesses into an oasis for bees, birds, and butterflies. Yet the recent study published in Biological Conservation finds that many retailers are dousing their ‘wildlife-friendly’ plants with pesticides that put this vulnerable species in further danger. “That was the most shocking part,” said lead author Christopher Halsch, a doctoral study at University of Nevada, Reno. “The fact that plants labeled as potentially beneficial or at least friendly to wildlife are not better and in some cases might be worse than other plants available for purchase. This research sheds light on how pesticides may impact western monarchs, but many other butterflies are facing even steeper population declines, and pesticides are likely one driver.” Testing was conducted by purchasing milkweed plants at 33 different stores spanning 15 different states. A sample of each plant was cut after purchase, and […]

(Beyond Pesticides, June 23, 2022) In the first California statewide bumble bee census in 40 years, a University of California—Riverside (UCR) study, published in Ecology and Evolution, reveals that once common bumble bee species in California are disappearing from the ecosystem. Wild pollinators like bumble bees provide pollination to billions of dollars worth of crops each year as these insects can flourish in cooler habitats and lower light levels than commercial honey bees. However, pollinators (such as bees, monarch butterflies, and bats) are a bellwether for environmental stress as individuals and as colonies. Both wild and commercial bees and other pollinators encounter multiple stressors, including pesticides, parasites, and poor nutrition, that act together to increase the risk of bee mortality. Therefore, studies like these highlight the need to establish monitoring and conservation frameworks incorporating varying habitats and species to assess fluctuations in biodiversity. The study notes, “Specifically, our study shows that greater monitoring of the diverse bumble bees of California is needed in order to better understand the drivers of biodiversity and decline in this genus, and to more effectively manage bumble bee conservation in the state.”  Researchers compared data on bumble bee populations in California in 1980 and 2020. After collecting bumble […]

(Beyond Pesticides, May 31, 2022) Fifty years after the banning of DDT, the notorious insecticide is still harming iconic birds of prey along the California coastline. According to research published in Environmental Science and Technology, California condors and marine mammals along California’s coast are contaminated with several dozen different halogenated organic compounds (hazardous, often-chlorinated chemicals) related to DDT, chlordane, and other now-banned legacy chemicals. The findings highlight the incredible importance of addressing these original “forever chemicals,” and making certain that we do not continue to repeat the mistakes of the past with new and different, yet equally dangerous, chemistries. Between 1947 and 1971, the Montrose Chemical Corporation of California, the largest historical producer of DDT, released over 1,700 tons of DDT into the LA sewer system, which eventually made its way into the Pacific Ocean. During this time, several other companies discharged PCBs, leading to further chemical contamination of land and sediment. As recent as April 2021, scientists discovered 25,000 barrels likely containing DDT near Catalina Island along the southern California coast. These releases have resulted in serious environmental and health problems throughout the coastal food chain. Yet, as the present study shows, scientists are only beginning to understand the […]

(Beyond Pesticides, February 23, 2021) The same pesticides implicated in the worldwide decline of insect pollinators also present significant risks to their avian counterparts, hummingbirds. Well known for their nectar-fueled hovering flight powered by wings beating over 50 times per second, hummingbirds display unique reactions to toxic pesticides. Research by scientists at the University of Toronto finds that hummingbirds exposed to systemic neonicotinoid insecticides for even a short period of time can disrupt the high-powered metabolism of this important and charismatic animal. Scientists began their experiment by trapping 23 wild ruby-throated hummingbirds and housing them in an animal care facility. One group of birds acted as a control and received no pesticide exposure, while the rest were assigned either low, middle, or high exposure (1 part per million [ppm], 2ppm, and 2.5ppm, respectively) to the neonicotinoid imidacloprid. Scientists determined these amounts based upon probable nectar contamination in the real world. The pesticide was incorporated into the sugar solution provided to the birds over the course of three days. Within two hours of exposure to the pesticides, hummingbird metabolism dropped significantly. While the control group increased energy expenditure between 1% to 7%, the low exposed group displayed a 6% average decline, […]

(Beyond Pesticides, January 27, 2021) Lowest ever recorded! That’s the result of a yearly winter monarch count along the California coast, overseen each year by the conservation group Xerces Society. In 2020, citizen scientists counted only 2,000 butterflies. The findings indicate that many on the planet today are likely to experience, within their lifetimes, a world where western monarchs are extinct—unless the federal government acts now. Western monarchs migrate from the Pacific Northwest to overwintering grounds along the California coast, where they remain in relatively stationary clusters that are easy to count.  In the 1980s, roughly 10 million monarchs overwintered along the coast. By the 1990s, that number fell into the low single digits, roughly 1.2 million. Five years ago counts were at roughly 300,000. By 2019, numbers crashed below 30,000. This year’s count saw no monarchs at iconic overwintering sites like Pacific Grove. Other locations, like Pismo State Beach Monarch Butterfly Grove and National Bridges State Park saw only a few hundred. “These sites normally host thousands of butterflies, and their absence this year was heartbreaking for volunteers and visitors flocking to these locales hoping to catch a glimpse of the awe-inspiring clusters of monarch butterflies,” said Sarina Jepsen, […]

(Beyond Pesticides, October 29, 2020) Natural areas around farmlands play an important role in managing pest outbreaks and therefore reducing insecticide use, a new study published in the journal Ecology Letters finds. While industrial agriculture puts pressure on farmers to grow single crops on ever larger farms to achieve economies of scale, these monoculture landscapes have significant downsides for public health and the environment. “Overall, our results suggest that simplified landscapes increase vineyard pest outbreaks and escalate insecticide spray frequencies,” said lead author Daniel Paredes, PhD, to the Daily Democrat. “In contrast, vineyards surrounded by more productive habitats and more shrubland area are less likely to apply insecticides.” To investigate the effect of nearby landscapes on farm pest pressure, the team of University of California, Davis scientists used a database created by the government of Spain. For 13 years, the government monitored 400 Spanish vineyards for the presence of the European Grapevine Moth. The moth is a notorious vineyard pest (discovered in California vineyards in 2009), laying three generations of eggs on grapes. In the first generation, the moth larvae will web and feed on flowers. In the second and third, they feed on berries, damaging harvests. Scientists developed a […]

(Beyond Pesticides, July 16, 2020) Long-term exposure to sublethal (low-level) concentrations of the neonicotinoid in soil negatively affects the health and behavioral development of black garden ants (Lasius niger) colonies, according to a study published in Communications Biology by scientists at the University of Bern, Switzerland. Ants are one of the most biologically significant insects in the soil ecosystem, acting as ecosystem engineers. Their burrowing behavior aerates the soil, allowing oxygen and water to penetrate down to plant roots. Additionally, ants increase soil nutrient levels by importing and accumulating organic material like food and feces, thus enhancing nutrient cycling. Like many other insects, ants are unfortunate victims of the global insect apocalypse or population decline, and much research attributes the recent decline to several, including pesticide exposure. Broad-spectrum pesticides, like neonicotinoids, indiscriminately kill pests and nontarget organisms alike, as their ubiquitous use contaminates soils, even in untreated areas. This study highlights the necessity of rethinking chemical pest management, developing sustainable agricultural practices that reduce the use of agrochemicals, like pesticides, to prevent permanent environmental ecosystem damage. Researchers in the study note, “To prevent irreparable damages to functioning ecosystems, [we] suggest to either fully incorporate long-term effects in risk assessment schemes, or to make a shift […]

(Beyond Pesticides, April 30, 2020) Chemical-intensive farming of crops for animal fodder powers the global market for highly hazardous pesticides (HHPs), according to data analyzed by Unearthed, and the Swiss NGO Public Eye. Animal fodder production not only intensifies global pollution, but it also increases pesticide exposure and degrades human, animal, and environmental health. This data analysis supports advocates advancing pesticide policies to eliminate HHPs by identifying which toxic chemicals lead global pesticide sales. However, it will take more than eliminating the worst chemicals to address the impending biodiversity collapse and the climate crisis, according to experts who point to the need for an urgent shift to organic land and agricultural management practices. United Nations’ (UN) special rapporteur on toxic substances and human rights, Baskut Tuncak, says, “There is nothing sustainable about the widespread use of highly hazardous pesticides for agriculture. Whether they poison workers, extinguish biodiversity, persist in the environment, or accumulate in a mother’s breast milk, these are unsustainable, cannot be used safely, and should have been phased out of use long ago.”  Unearthed and Public Eye investigated over $23 billion in global pesticide market sales to determine the proportion of pesticides considered highly hazardous by the Pesticide Action Network’s […]

(Beyond Pesticides, April 23, 2020) Pesticide spray drift from adjacent farmlands expose butterfly larvae to lethal pesticide concentrations, according to research published in Environmental Toxicology and Chemistry by Iowa State University (ISU). Lack of previous experimental pesticide toxicity data makes it unclear as to what degree insecticides impact monarch butterfly (Danaus plexippus) productivity in milkweed (Asclepias spp.) habitats near pesticide-treated pasture. This study adds weight to the idea that pesticides are playing a role in the ongoing decline of this iconic butterfly, as researchers find insecticide drift from adjacent fields to be strongly associated with larval mortality. Future monarch butterfly conservation efforts should consider risks stemming from pesticide exposure when developing butterfly rehabilitation efforts, according to advocates. As co-author Niranjana Krishnan (ISU graduate student) states, “In order to make the best decisions about how and where to plant milkweed, we first need to find basic toxicity and exposure data.”  ISU researchers established monarch butterfly colonies by collecting larvae from roadside milkweeds, which they then reared in the laboratory for incubation. To analyze the relative toxicity of various insecticides on monarch butterflies, researchers applied normal field-application rates of each pesticide at different larval development stages. Scientists used a bioassay to measure the […]