(Beyond Pesticides, April 8, 2025) A comprehensive literature review in Environment & Health analyzes evidence from human biomonitoring, epidemiological studies, and toxicological studies that link adverse effects on women’s reproductive health, specifically impacting the ovary, to pesticide exposure. In examining the scientific literature, consisting of over 200 studies performed in the last 25 years, the authors find pesticide exposure threatens women’s health through ovarian dysfunction. “Epidemiological studies have shown that pesticide exposures are associated with early/delayed menarche [first occurrence of menstruation], menstrual cycle disorders, early menopause, long time to pregnancy, polycystic ovary syndrome, primary ovarian insufficiency, infertility, and implantation failure in women,” the researchers state. They continue, “Both in vivo [in animals] and in vitro [in cells] studies have shown that exposure to pesticides disrupts the estrous cycle, reduces the follicle pool, alters hormone levels, and impairs oocyte [egg] maturation.” These reproductive implications are noted with many different classes of pesticides, such as insecticides, including organochlorine pesticides (OCPs), organophosphates (OPs), pyrethroids, and neonicotinoids, as well as herbicides and fungicides. The authors, however, comment on present research gaps: “Much of the available epidemiological evidence focuses on legacy insecticides, such as OCPs, and a subset of insecticides that are still in use […]

(Beyond Pesticides, April 7, 2025) Throughout the year and historically, the science and policy deficiencies captured by the Daily News paint a dramatic picture of the issues that support the need for strong organic standards on a range of issues, some of which will be under consideration by the National Organic Standards Board (NOSB) when it receives public comments through Monday, April 28. Organic advocates are gearing up to participate in the hearing process and the semi-annual meeting of the NOSB to protect and enhance the integrity of defined, certified, and enforceable organic standards as an alternative to harmful chemical-intensive practices. Because of USDA’s delay in scheduling the NOSB meeting, board members will not have time to review public comments unless they are submitted as soon as possible before the start of the board meeting on April 29. So, Beyond Pesticides is encouraging members of the public to comment early. There are public comment webinars on April 22 and 24 and a deliberative hearing from April 29 through May 1, that concern how organic food is produced. A draft meeting agenda is available here; a more detailed agenda with proposals is available here. Sign up for a 3-minute oral public comment timeslot to let the U.S. Department of […]

(Beyond Pesticides, April 4, 2025) In March, the California Department of Pesticide Regulation (DPR) announced the launch of SprayDays California, “a first-of-its-kind statewide system designed to provide transparent, accessible and timely notifications and information about the use of specific pesticides[,]“ according to the agency’s press release. The state says that notification will occur in “advance of the scheduled use of California restricted material pesticides in production agriculture.” Growing out of the passage of AB 617 Community Emissions Reduction Act in California, passed in 2017, farmworker safety advocates have long been urging an implementation strategy that provides notification of pesticide spraying. In late 2017, the California Air Resources Board (CARB) began implementation of AB 617, a bill enacted with the stated intent of addressing the air quality crisis in many communities of predominantly people of color who are disproportionately harmed by toxic chemicals. While the overall goal of the law is to reduce air pollution in these communities, farmworker advocates have sought to operationalize a pesticide spraying notification system to warn communities when nearby spraying is scheduled to take place. The idea behind notification programs and transparency in government is that it enables those potentially exposed to take precautionary measures to […]

(Beyond Pesticides, April 3, 2025) As highlighted by Beyond Pesticides in recent comments to the U.S. Environmental Protection Agency (EPA), chlorpyrifos (CPF) has been under scrutiny for decades due to associated adverse health effects, noted particularly in the extensive and consistent scientific evidence of neurotoxic dangers to children’s health. The latest research on CPF, published in Environmental Toxicology and Genes & Diseases, reveals additional threats to the immune system and male reproduction that are not captured in current EPA risk assessments of chlorpyrifos and raises serious health questions, given that residues are found throughout the food supply. CPF, a widely used organophosphate insecticide in agriculture, is a cholinesterase inhibitor that binds irreversibly to the active site of an essential enzyme for normal nerve impulse transmission, acetylcholine esterase (AChE), inactivating the enzyme. Many insecticides, including organophosphates and carbamates, target AChE, causing them to be highly toxic to both insects and mammals that have this enzyme as a crucial part of their nervous systems. The history of chlorpyrifos exemplifies the failure of pesticide law and policy, as this chemical, among many others, not only has direct adverse health effects but is contributing to the climate crisis, biodiversity collapse, and disproportionate levels of […]

(Beyond Pesticides, April 2, 2025) In examining prenatal residential proximity of documented pesticide spraying in California to the menstrual cycle characteristics of 273 Latina adolescents, researchers report in the American Journal of Epidemiology a positive association between exposure to the insecticide methomyl and heavy bleeding. Other pesticides appear to influence menstrual symptoms as well. “Adolescents’ menstrual cycle characteristics can be ‘vital signs’ of health and impact quality of life,” the authors share. They continue, “To our knowledge, this is the first study to examine the association between prenatal pesticide exposure and menstrual outcomes in adolescents of any demographic group.” Menstrual cycle characteristics, such as dysmenorrhea (painful or uncomfortable menstrual cramps), irregularity, and heavy menstrual bleeding, can also be indicators of underlying health conditions, including endometriosis, polycystic ovary syndrome (PCOS), thyroid dysfunction, and bleeding disorders. By associating the pesticide exposure of mothers during pregnancy to impacts on their children, the researchers highlight important health risks for women and young girls that are often disregarded. “The prenatal period is a critical period of reproductive development that may be particularly sensitive to endocrine disruption,” the researchers share. As previously reported by Beyond Pesticides, endocrine-disrupting chemicals are any synthetic or natural compounds that hinder […]

(Beyond Pesticides, April 1, 2025) With the second largest award of nearly $2.1 billion (see reporting on largest), a jury in Georgia state court on March 21 found the pesticide manufacturer Bayer/Monsanto guilty of causing a man’s non-Hodgkin’s lymphoma after use of the company’s glyphosate-based weedkiller RoundupTM product. The jury’s award includes $65 million in compensatory and $2 billion in punitive damages, as reported by the Associated Press and Courtroom View Network. This verdict in Barnes v. Monsanto (2025) comes amid a concerted effort by Bayer and other chemical and agribusiness groups to take away the main legal argument, “failure-to-warn,” for the type of litigation that pesticide exposure victims have commonly used to hold companies accountable. This is happening as Governor Brian Kemp of Georgia considers signing into state law a pesticide immunity bill that will prevent future litigation like this in the state. In a deregulatory environment, the courts and state governments are viewed as critical backstops, given the dismantling of the U.S. Environmental Protection Agency’s (EPA) regulatory apparatus and extremely limited Congressional oversight. History of Litigation Bayer has lost almost all of the cases filed against it for compensation and punitive damages associated with the plaintiffs’ charge that […]

(Beyond Pesticides, March 28, 2025) The Rhine Valley in southwestern Germany is renowned for the agricultural bounty it has provided for centuries. Today, the area is home to dense wine, vegetable, fruit, and cereal cultivation. However, a study shows that current regulation of pesticides, even in the relatively progressive European Union, is inadequate to protect humans and all the other organisms that produce the environment necessary for human life and civilization.  The study goal was to determine how far—and which—pesticides traveled beyond the croplands of vegetables, fruit orchards, and cereals, as well forested lands, into nontarget areas that should serve as refugia for plants, animals, and invertebrates not considered pests. Based at the Landau Institute for Environmental Sciences at the University of Kaiserslautern-Landau, the researchers used innovative methods to measure the types, concentrations, and distribution of pesticides. They took samples from three landscape categories—vegetation, topsoil, and surface water—at 78 sites distributed along six transects, each reaching from the valley floor to the tops of the mountains on either side. Samples were taken from grasses, shrub leaves, and topsoils along each transect, together with water samples from rivers, small streams, ponds, and puddles. They tested for 93 current-use pesticides (CUPs). There […]

(Beyond Pesticides, March 27, 2025) In Ecotoxicology, results of a study on Nile tilapia (Oreochromis niloticus) exposed to florpyrauxifen-benzyl (FPX) suggest the new herbicide causes oxidative stress (imbalances affecting the body’s detoxification abilities that lead to cell and tissue damage), with specific genotoxic (damage to genetic material) and hepatotoxic (damage to the liver) effects on nontarget species. The authors state: “According to the available literature, no data exist on the toxicity of FPX in fish. Therefore, this study aims to investigate, for the first time, the potential toxicity and associated mechanistic effects of the pyridine-carboxylic acid herbicide (FPX) on the non-target species, Nile tilapia.” According to the Wisconsin Department of Natural Resources, “Florpyrauxifen-benzyl is a systemic herbicide (i.e., it moves throughout the plant tissue). It is a WSSA Group 4 herbicide, meaning that the mechanism of action is by mimicking the plant growth hormone auxin and causing excessive elongation of plant cells, ultimately killing the plant.” The researchers, from Menoufia University, the Agricultural Research Center, and Cairo University in Egypt, focus on FPX as it is the active ingredient in Divixton 2.5% EC, a newly released herbicide used in rice fields and applied directly to freshwater aquatic bodies for emergent […]

(Beyond Pesticides, March 25, 2025) An editorial in Expert Review of Cardiovascular Therapy finds that triazole fungicides pose a significant risk of cardiotoxicity with “growing concerns regarding their safety for human health, especially in long-term exposure,” the authors share. After analyzing the known mechanisms of cardiotoxicity of triazole pesticides in mammals, they conclude that “the most effective approach to mitigating triazole-induced cardiotoxicity lies in prevention.”  Triazoles, a class of fungicides, target fungi by inhibiting the biosynthesis of ergosterol, an essential component of their cell membranes. As the researchers share, “Compounds such as tebuconazole, propiconazole, and difenoconazole are among the most used triazoles in agriculture.” Triazoles are utilized as antifungal medications, despite the rise of resistant infections, in addition to their use as systemic pesticides on many fruit and vegetable crops, including grapes, wheat, corn, and soybeans.   As Beyond Pesticides’ previous coverage indicates, many triazole fungicides in the U.S. are registered for use despite evidence of endocrine disruption established over a decade ago in a U.S. Geological Survey report. These pesticides exhibit common mechanisms of toxicity often disregarded in U.S. Environmental Protection Agency (EPA) risk assessments, with a multitude of studies showcasing the myriads of health threats that the agency does […]

(Beyond Pesticides, March 18, 2025) The November 2024 press release by the U.S. Environmental Protection Agency (EPA) for its Rodenticide Strategy includes the final biological evaluation (BE) of 11 rodenticides. Prior to the finalization of the BE, Beyond Pesticides commented to EPA’s Office of Pesticide Programs in early 2024, disagreeing with the categorical no effect (NE) determinations for all freshwater and marine fish, aquatic mammals, aquatic amphibians, aquatic reptiles, and aquatic invertebrates. (See related Daily News and Action of the Week.) The latest scientific literature highlights the impacts of rodenticides on nontarget organisms, including aquatic organisms that the agency failed to evaluate due to harm that was, as EPA says, “not reasonably certain to occur.” Many rodenticides, intended to target rats, mice, squirrels, nutria, and more, are anticoagulants and stop normal blood clotting. Active ingredients in these pesticides can include bromadiolone, chlorophacinone, difethialone, brodifacoum, and warfarin. Anticoagulant rodenticides (ARs), contrary to the agency’s assertions, can be transported to aquatic ecosystems, including both freshwater and marine environments. As mentioned in Beyond Pesticides’ comments, ARs have been detected in raw and treated wastewater, sewage sludge, estuarine sediments, suspended particulate matter, and liver tissues of sampled fish, demonstrating that the aquatic environment experiences […]

(Beyond Pesticides, March 17, 2025) When Secretary of Health and Human Services Robert F. Kennedy, Jr. announced last week that he is directing the U.S. Food and Drug Administration (FDA) to explore rulemaking to review substances in food affirmed by the food companies to be Generally Recognized as Safe (GRAS), he said he is “committed to promoting radical transparency to make sure all Americans know what is in their food.” The issue of independent review of the food industry’s GRAS declarations has long been the subject of critiques raising public health concerns. As this issue emerged, on another food safety issue, Beyond Pesticides is asking  FDA to use its broad authority under the Federal Food, Drug, and Cosmetic Act to “ensur(e) that human foods and animal feeds are safe” from residues of pesticide mixtures, in light of new troubling scientific data. Under various memoranda of understanding between FDA, the U.S. Environmental Protection Agency (EPA), and the U.S. Department of Agriculture (USDA) going back decades, FDA could consult with EPA on food safety issues ignored by the agency, including  recent data published in Pesticide Biochemistry and Physiology, which “suggest that combined [pesticide] exposure may further amplify the toxicity and compromise the intestinal […]

(Beyond Pesticides, March 13, 2025) Study results published in Pesticide Biochemistry and Physiology “suggest that combined [pesticide] exposure may further amplify the toxicity and compromise the intestinal barrier.” The researchers studied the toxic effects of the insecticides abamectin and spirodiclofen, as well as the fungicide fluazinam, individually and in combination. In exposing mice and Caco-2 cells to these pesticides, the results show the disruption of intestinal functions and highlight the need to assess potential synergistic effects of pesticide mixtures as a part of the regulatory review process.  Effects on the intestinal barriers of mice represent a threat to “the first line of defense against the external environment,” the researchers say. The intestinal mucosal epithelial structure plays an important role in preventing harmful substances from entering the intestines and causing damage to cells.  [Caco-2 cells represent a human cell line, derived from a colon cancer patient’s tissue, and mimic the small intestine. These cells are vital in research as a model of the intestinal epithelial barrier.]  “Currently, most studies investigating the effects of pesticide residues on the barrier function of Caco-2 cells concentrate on the exposure to a single residue, while the potential toxic effects arising from the concurrent presence of multiple pesticide […]

(Beyond Pesticides, March 11, 2025) A study in Toxics analyzes ipconazole, a triazole fungicide often used as a coating on treated seeds and as a foliar treatment on the leaves of plants. “Triazole pesticides are widely used throughout the world, but their abuse causes toxic effects in non-targeted organisms,” the researchers state. In the current study, unintended reproductive effects are noted in male sheep (ram) and pigs (also known as porcine or swine). This research focuses on the impact of ipconazole exposure on spermatozoa (sperm) in two mammal species and finds spermiotoxicity through significantly reduced sperm viability, as well as alterations in enzyme and gene expression related to fertility.  “To our knowledge, this is the first study to evaluate the cytotoxic effect of the triazole ipconazole on mammalian spermatozoa,” the authors share. This analysis utilizes semen samples from the Reproductive Biotechnology Laboratory of the Major National University of San Marcos in Lima, Peru, the university where six of the nine researchers are Faculty of Veterinary Medicine.   “The sperm were exposed to ipconazole concentrations of 1, 5, 10, 50 and 100 µM, and to a control without ipconazole,” they say. Similar concentrations have been used in previous cytotoxicity studies with ipconazole. […]

(Beyond Pesticides, March 4, 2025) A study in GeoHealth of pediatric cancers in Nebraska links exposure to agricultural mixtures with the occurrence of these diseases. The authors find statistically significant positive associations between pesticide usage rates and children with cancer, specifically brain and central nervous system (CNS) cancers and leukemia. “Our study is the first to estimate the effect of an agrichemical mixture on the pediatric cancer rate in Nebraska,” the study authors share. “One significant advantage of our study is that we identified the pesticide consistently applied over 22 years in Nebraska counties and then estimated the overall mixture effect of these pesticides on pediatric cancer.” The elevated effect of pesticide mixtures, a reality that is not evaluated in the U.S. Environmental Protection Agency’s (EPA) pesticide registration program, was reported in Oecologia (2008), documenting harm to amphibian populations even if the concentration of the individual chemicals is within limits considered acceptable. (See additional coverage here.) There is a wide body of science highlighting the disproportionate risk of adverse health effects in children with pesticide exposure. Their small size and developing organ systems, propensity to crawl and play near the ground, tendency for frequent hand-to-mouth motion, and greater intake of […]

(Beyond Pesticides, February 27, 2025) In analyzing current scientific literature and data on glyphosate-based herbicides (GBHs), a research article in Environmental Sciences Europe finds that glyphosate (GLY) persists in bones before reentering the bloodstream. The mechanisms in which GLY interacts with important cells for development, called hematopoietic stem cells (HSCs), and breaks and rearranges DNA offer a possible explanation for the heightened risk of cancer, specifically blood cancers like non-Hodgkin lymphoma (NHL), myeloma, and leukemia. “Existing data on GLY/GBH metabolism and genotoxicity provide critical insights into how exposures may be contributing to blood cancers,” according to the study’s author, Charles Benbrook, PhD. Dr. Benbrook continues: “A significant portion of GLY reaching blood moves quickly into bone marrow and then bone, where it can bioaccumulate and persist… Data reviewed herein suggest that a portion of the GLY excreted by most people on a daily basis can be traced to the shedding of calcium-GLY complexes in bone back into the blood supply.” This allows for near-constant contact between glyphosate molecules and hematopoietic stem cells, which are immature cells that can develop into any type of blood cell. Mutations in hematopoietic stem cells can cause blood cancers to emerge. Those at disproportionate risk […]

(Beyond Pesticides, February 25, 2025) A literature review of over 90 scientific articles in Agriculture documents microplastics’ (MPs) increase in the bioavailability, persistence, and toxicity of pesticides used in agriculture. The interactions between MPs and pesticides enhance the threat of pesticide exposure to nontarget organisms, perpetuates the cycle of toxic chemical use, and decreases soil health that is vital for productivity. “The increasing presence of MPs in agricultural ecosystems has raised concerns about their impact on pesticide bioavailability, efficacy, and environmental behavior,” says study author Kuok Ho Daniel Tang, PhD, a global professor in the Department of Environmental Science at the University of Arizona. He continues, “These synthetic particles interact with pesticides through adsorption and desorption processes, altering their distribution, persistence, toxicity, and uptake by plants and other organisms.” Microplastics in the Environment As Beyond Pesticides has previously reported, microplastics are ubiquitous and threaten not only human health but all wildlife in both aquatic and terrestrial ecosystems. The universal distribution of plastics means that they cannot be avoided. Humans and other organisms take up plastics in the form of microparticles and nanoparticles by inhalation, ingestion, and skin contact every day. Microplastics are about the width of a human hair; nanoplastics […]

(Beyond Pesticides, February 20, 2025) Researchers at the University of Oregon found that the rollout of genetically engineered corn in the early 2000s, followed by exponential increases in glyphosate-based herbicides, “caused previously undocumented and unequal health costs for rural U.S. communities over the last 20 years.” Their results “suggest the introduction of GM [genetically modified] seeds and glyphosate significantly reduced average birthweight and gestational length.” The conclusions of this study emerge as fossil fuel advocates, including President Donald Trump, are mobilizing to pioneer “energy dominance” despite the market movement toward renewable energy. Just as chemical-intensive farmers and land managers continue to spray synthetic fertilizers and pesticides, a successful rollout of alternatives must rely on feeding the soil rather than the plant. Advocates continue to demand that elected officials and regulators embody the precautionary principle and scientific integrity in decision-making. Given the hostile federal climate on anything relating to holistic solutions, communities are coming together to move beyond input-dependent land management systems and adopt organic criteria of allowed and prohibited substances, mandatory public comment process, independent third-party certification, and a federal advisory board (National Organic Standards Board) consisting of farmers, environmentalists, consumers, scientists, economists, researchers, and other stakeholders, with binding recommendations […]

(Beyond Pesticides, February 11, 2025) In a Science of The Total Environment study, scientists test over 100 blue tit (Cyanistes caeruleus) and great tit (Parus major) birds’ nests for pesticide residues in comparison with the number of dead offspring and unhatched eggs within the nest. Fur-lined nests, from animals treated with ectoparasitic chemicals, expose birds to compounds that can impact reproductive success. The authors found fipronil, a phenyl pyrazole insecticide, in all nests, with the majority also containing the neonicotinoid insecticide imidacloprid and synthetic pyrethroid insecticide permethrin. The data shows higher insecticide levels are linked to increased offspring mortality and threaten biodiversity. This study highlights an important exposure route that is overlooked. “Although not all bird species use fur for nest building, a substantial number do, especially cavity-nesting species,” the researchers share. “Previous research found that 74% of studied woodland bird species in central Europe incorporated fur into their nests.” Many bird species in the U.S. also line their nests with fur, such as black-capped chickadees, tufted titmice, and chipping sparrows. While there is a wide body of science showing reproductive effects from pesticides, the researchers highlight the study’s novel design, saying, “To the best of our knowledge, no previous […]

(Beyond Pesticides, February 7, 2025) With the strong associations established in epidemiologic studies and a dearth of evidence on the actual mechanisms by which pesticides inflict their damage on the brain, a new meta-analysis identifies studies that pesticides can overwhelm cells’ defenses against them, interfere with cell communication in the brain, and disrupt the epigenetic (gene function) regulation of gene expression. In the journal Nucleus, Bilal Ahmad Mir, PhD and colleagues at the University of Kashmir in Srinagar, India, review what is known at the molecular level about pesticides’ role in brain cancer. Brain cancer is a heavy burden for its victims and their families, and attributing a cause is, as with many diseases, fraught with difficulty. But there are strong clues: For example, farming is a known risk factor. In a 2021 meta-analysis of epidemiologic studies between 1998 and 2019, analyzed here by Beyond Pesticides, farming was associated with a 13% increase in the risk of brain cancer. For farmers whose specific exposure to pesticides was documented in the studies, the increase jumped to 20 percent. So there is some reason to point a finger at synthetic chemicals. But agricultural workers are not the only ones at risk. According […]

(Beyond Pesticides, February 6, 2025) Months after publishing a June 2024 study regarding concentrations of pesticides discovered in legal (and illegal) cannabis products in California, the Los Angeles Times has released a follow-up exposé highlighting extensive pesticide contamination, including from “hidden” pesticides that regulators have not monitored. The authors conclude that in California’s legal weed market, over half of available smoking products are found to contain hidden chemicals—toxic pesticides present in products but not regulated or monitored by state authorities. Since 2015, Beyond Pesticides has laid out health, safety, and environmental concerns related to the contamination of cannabis by pesticides (and fertilizers) alongside an imperative need to mandate an organic systems approach to cannabis production. Yet ten years later, it appears nationally that California state regulators are alone in moving forward in 2021 with state organic cannabis certification. There are other marketplace-based cannabis certification labels that require comparable organic certification practices (see Beyond Pesticides reporting here and here). For more information, please see past Pesticides and You reporting here and here. The Los Angeles Times analyzed the results from state licensed laboratory testing of more than 370 legal cannabis products, representing 86 brands. In addition to the 66 chemicals required […]

(Beyond Pesticides, February 5, 2025) A study in PLOS One finds acute and chronic impacts of nontarget toxicity on the American burying beetle, Nicrophorus americanus, with neonicotinoid insecticide exposure. In assessing environmentally relevant concentrations of the neonicotinoid insecticide imidacloprid with N. americanus, the researchers note both mortality and behavioral effects that leave the species at high risk of predation. These effects mean the American burying beetle “may be at greater risk to insecticide exposure than previously thought and vulnerable to episodic, low-dose neonicotinoid exposure,” the authors say. This data sheds important light on a species that has been listed by the U.S. Fish and Wildlife Service (USFWS) as threatened. Burying beetles provide important ecosystem services within the environment such as “burying carrion, increasing available nutrients in soil, and expediting carrion decomposition, while acting as a food source for secondary consumers,” the researchers state. (See more on ecosystem services and beneficial insects here, here, and here.) The N. americanus species are habitat generalists and can be found in grasslands, wet meadows, and forested areas that neighbor agricultural lands and introduce the beetles to pesticide drift and soil residues. While acute and chronic effects vary in duration and severity, pesticide exposure resulting […]

(Beyond Pesticides, January 31, 2025) A recent cross-sectional study in Heliyon highlights the link between sleep disorders in Thai farmers and pesticide exposure. The authors find pesticide exposure as an important risk factor for sleep disorders after surveying 27,334 farmers over the age of 20 who had work experience for at least five years. The importance of sleep health is reflected both physically and mentally, as studies find “sleep deficiency increase[s] mortality and various health complications, including hypertension, obesity and type 2 diabetes, cardiovascular diseases, mood disorders, and neurodegenerative disorder.” Additional studies find that these issues are compounded when sleep health is affected by environmental factors such as pesticide exposure. (See previous Beyond Pesticides’ coverage here and here.) The researchers report: “The study found a positive association of 19 individual pesticides (twelve insecticides, two herbicides, and five fungicides). Some associations demonstrated a dose-response pattern. Additionally, the study revealed that women are at a higher risk of sleep-related issues with pesticide exposure compared to males. These results not only substantiate existing literature but also unveil several new individual pesticides that may impact sleep health.” Focusing on study participants in Thailand, which is “characterized by heavy pesticide use and minimal protective measures, […]

(Beyond Pesticides, January 30, 2025) A research article in Biology Letters, published by The Royal Society, finds that the neonicotinoid insecticide imidacloprid disrupts survival and reproductive patterns in Bombus impatiens bumblebees. The study adds to the wide body of science highlighting how exposure to pesticides “can result in immediate mortality or cause long-term detrimental effects on pollinators‘ health, lifespan and reproductive success,” the authors state. The researchers performed two experiments to assess the effects of various concentrations of imidacloprid, one of which focuses on bees during diapause, a period of dormancy. “Wild bees, which provide the majority of pollination services worldwide, undergo an annual life cycle that includes a winter diapause, that can span over 75% of their life cycle and during which their metabolism, growth and development are halted,” the authors note. They continue: “The time spent in diapause can have lasting effects on pollinator fitness and their ability to establish nests or colonies in the following spring. This period is especially critical for social bee colonies, which are founded by a single queen after diapause and play a vital role in large-scale pollination.” Exposure to pesticides during diapause can occur while bee species overwinter in contaminated soils. In […]