{"id":35619,"date":"2024-06-28T00:01:46","date_gmt":"2024-06-28T04:01:46","guid":{"rendered":"https:\/\/beyondpesticides.org\/dailynewsblog\/?p=35619"},"modified":"2024-06-28T11:28:14","modified_gmt":"2024-06-28T15:28:14","slug":"seeds-coated-with-neonicotinoid-insecticides-again-identified-as-important-to-butterfly-decline","status":"publish","type":"post","link":"https:\/\/beyondpesticides.org\/dailynewsblog\/2024\/06\/seeds-coated-with-neonicotinoid-insecticides-again-identified-as-important-to-butterfly-decline\/","title":{"rendered":"Seeds Coated with Neonicotinoid Insecticides Again Identified as an Important Factor in Butterfly Decline"},"content":{"rendered":"\r\n

(Beyond Pesticides<\/em>, July 28, 2024) Most people don\u2019t like bugs, but the fact is that insects form the foundation of human flourishing, both for their ecosystems services, like pollination of food crops, and for their aesthetic joys. But insect populations globally are declining two to four percent a year, with total losses over 20 years of 30-50 percent, according to a new study<\/a> of the interacting effects of pesticides, climate, and land use changes on insects\u2019 status in the Midwest. Teasing out the relative influence of these stressors has been a major obstacle in determining the causes of the declines and ways to mitigate them.<\/p>\r\n

The icon of insect beauty<\/a> in the U.S. is the monarch butterfly, whose vibrant coloring, elegant form, and spectacular migrations inspire everyone. Beyond Pesticides has covered the distressing decline of these creatures, most recently in the June 24 Daily News. Monarchs prefer milkweed plants, but also visit many other flowers. Milkweed often grows along the margins of fields, so monarchs are widely exposed to pesticides and habitat disturbances associated with agriculture.<\/p>\r\n

The new study was published in PLoS One<\/em> by a team of scientists from the Washington Department of Fish and Wildlife, Michigan State University, Iowa State University, and Georgetown University. Of the three drivers of insect loss, the study confirmed unequivocally that insecticides lead the pack in causing the loss of richness and abundance in Midwest butterfly species, particularly monarchs. \u201cOverall declines are overwhelmingly supported by the evidence,\u201d they write. Monarchs, bumblebees, dragonflies and lowland butterflies all drop catastrophically in areas where pesticides are used.<\/p>\r\n

In the pesticide category, the study considered weed control (herbicides including glyphosate), reactive insect control (the sprayed insecticides pyrethroids and organophosphates), and prophylactic insect control (neonicotinoid-treated and Bt genetically modified seeds). The researchers considered all of the highest-use pesticides including their main active ingredient, target organisms, application timing, and mode of application (preventive, as on seeds or in soils, or reactive, in response to pest outbreaks), whether the pesticide spills over into nontarget areas, and how persistent it is in the environment. And while the steep crash of monarch butterflies coincides neatly with the introduction of glyphosate, the authors note that while herbicides reduce habitat diversity sharply, they do not directly kill insects like pesticides do. The study\u2019s end result was clear: seeds coated with neonicotinoids are causing the most damage.<\/p>\r\n

Neonicotinoids are the most widely used insecticide type in the world. While generally considered less toxic to mammals than organochlorines and carbamates, but much more toxic to a wider variety of insects\u2014not just pests but also beneficials and charismatic butterflies, their serious adverse impacts on human health are becoming increasingly defined. (See here<\/a> and here<\/a>.) Up to 85 percent of applied neonicotinoid insecticides, including on seeds, can leach into the environment. Thus, beyond exposure to neonicotinoids via plant tissue or direct spray, there is deep concern about the residues that remain in soil and water and are incorporated into non-target plants.<\/p>\r\n

The study used advanced and innovative methods to overcome the difficulty of determining the relative influence of pesticides, climate and land use changes. In their target region of the Midwest, agriculture comprises 60 percent of land use in most counties, and corn and soybeans dominate the crop types. The Midwest also has the densest network of butterfly monitoring activities, which the researchers accessed for species and abundance data.<\/p>\r\n

Large-scale climate and land use data are also publicly available, and changes in these factors can be sensed remotely. But acquiring reliable information about pesticides is frustrating because much of it is protected by the obscurantism of chemical companies and the shirking of responsibility by regulators. Granular data about pesticide use does exist, but this data is often proprietary. To get that data, the researchers acquired results of an annual survey called AgroTrak, conducted by Kynetec, Inc., a market research company. The survey draws from databases of growers who receive federal payments, membership lists of farmers\u2019 associations, and subscribers to agricultural publications, correlated with USDA groupings of areas with similar climate, geography and cropping practices. Respondents to the survey provide information from the previous year about which seeds they use and the types and amounts of pesticides they have applied to individual fields.<\/p>\r\n

Importantly, the data the researchers used included information about neonicotinoid usage only between 1998 and 2014, after which the market research company stopped asking its respondents about whether they used neonicotinoid-treated seeds. This was apparently because farmers are less knowledgeable about the pesticides in treated seeds, so the survey did not draw out accurate data.<\/p>\r\n

This problem was also analyzed by a 2020 report, \u201cSowing Uncertainty: What We Do and Don\u2019t Know about the Planting of Pesticide-Treated Seed<\/a>.\u201d To get around this data gap, Sowing Uncertainty<\/em><\/a> collected information from other, publicly available sources, but these often have their own weaknesses. For example, the USDA conducts annual voluntary surveys of farmers growing major crops (corn, soybeans, wheat and cotton), but conclusions from this data are also problematic because the data is aggregated and does not provide field-level information. Europe is a patchwork of reporting requirements, some of which provide fairly detailed data, but again, seed treatments are either not reportable or are lumped in with other pesticide uses. The best source of pesticide use data is the State of California, because it requires commercial applicators to report. But seed treatment is not defined as a pesticide in California. Clearly the status of pesticide-treated seeds must be clarified by regulators and included in reporting requirements. Its omission from the reporting system is an example of policy dictated by economic interests.<\/p>\r\n

This is despite the rising use of treated seeds. For example, according to Sowing Uncertainty<\/em><\/a>,<\/em> \u201cOver the 2012\u20132014 period, approximately 90% of corn, 76% of soybean, 62% of cotton, and 56% of winter wheat acres in the United States were planted with treated seed.\u201d Yet, the report stresses, government data gathering concentrates on field-applied pesticides.<\/p>\r\n

Attempts to reduce the threat from neonicotinoids in general and seeds treated with them have had mixed success. In the U.S., the U.S. Environmental Protection Agency (EPA) amended the Federal Insecticide, Fungicide, and Rodenticide Act<\/em> (FIFRA) in 1988 to allow manufacturers and sales companies not to register or label pesticide-treated articles including seeds, so they are not included in the pesticide use data the Food Quality Protection Act requires USDA to collect.<\/p>\r\n

The European Union totally banned neonicotinoids for outdoor use in 2018, and in the U.S. the next year, neonicotinoid manufacturers caved to a lawsuit <\/a>by beekeepers and environmental NGOs and asked EPA to cancel the registrations for a dozen of the 59 neonicotinoid products containing clothianidin and thiamethoxam. EPA has already found that three neonicotinoids\u2014clothianidin, imidacloprid and thiamethoxam\u2014are likely to adversely affect<\/a> the vast majority of endangered species. Beyond Pesticides covered this issue here<\/a>. Currently, EPA lists five neonicotinoids under registration review<\/a>\u2014including those three\u2014which it optimistically plans to complete in 2024.<\/p>\r\n

The PLoS<\/em> study points directly to neonicotinoids as the leading culprit in monarch losses\u2014but, the authors write, this \u201cdoes not align with the relationship between neonicotinoids and monarch mortality in lab toxicology studies; indeed these lab studies show that neonicotinoids are among the least toxic agents.\u201d This, Beyond Pesticides believes, highlights a severe problem with the methods used by regulators to assess harms to plants, animals, fungi and ecosystems from industrial chemicals: regulatory toxicology tests.<\/p>\r\n

EPA, the Food and Drug Administration (FDA), and other agencies require chemical manufacturers to run batteries of antiquated tests on thousands of laboratory animals, usually culminating in calculating the LD50, or the dose at which half of the test animals die. The companies either conduct the tests and report the result to regulators themselves or outsource the tests to one of the many bespoke consultancies available to produce the desired results. Rarely do the tests include measures of cumulative health effects over time or at the animals\u2019 most vulnerable life stages; nor do they often assess the combined effects of multiple chemicals.<\/p>\r\n

Nor is there a requirement for chemical testing to be conducted together with other stressors such as those examined in the current study, namely climate and land use changes, especially habitat loss. Laboratory tests, the authors note, estimate \u201cfield-relevant exposure levels to be well below those expected to cause monarch mortality,\u201d but this disregards the fact that seed treatments vastly increase the buildup of neonicotinoids in the environment. Nor can lab tests determine sub-lethal effects on monarchs in the environment. Laboratory results simply do not predict real-world consequences.<\/p>\r\n

The authors emphasize that, because their dataset stopped in 2014, they were not able to consider the effects of climate change since then. The hottest years on record have occurred recently and surely must be affecting monarch abundance and survival more severely than they observed in their study. Even so, climate is unlikely to have outpaced pesticides as the most grievous harm being inflicted on these iconic butterflies and insects in general. Further, the glacial pace of regulatory action contrasts with the breakneck speed of pesticides\u2019 accumulating consequences to insects and ecosystems. Insect loss means bird loss, estimated at 3 billion<\/a> in the U.S. over the last 50 years. As the PLoS authors emphasize, there is an urgent risk of ecosystem collapse. Yet EPA and other federal agencies continue to give the worst culprits, neonicotinoid treated seeds, a free pass.<\/p>\r\n

What you can do:<\/p>\r\n