01
Jul
(Beyond Pesticides, July 1, 2021) Yellow fever mosquitoes (Aedes aegypti) are evolving resistance to the pyrethroid insecticide permethrin, according to a study published by Colorado State University, highlighting the need to adopt ecologically-based mosquito management. Widespread, intensive use of the pesticide in mosquito control has allowed genetic mutations to persist among these mosquito populations, causing subsequent resistance to permethrin. Pyrethroids are one of the few remaining classes of insecticides available to control yellow fever mosquitos, and resistance threatens the ability to prevent disease outbreaks with chemical-intensive methods. Yellow fever mosquitoes are a vector for numerous untreatable diseases in humans, including dengue, chikungunya fever, and Zika viruses. Hence, this study highlights the significance of addressing pest resistance to pesticide control, particularly to mitigate disease exposure and effects. The researchers note, “This knowledge can help scientists understand how mosquitoes have evolved resistance and when a population can no longer be controlled with permethrin. This understanding will be necessary to develop tools to support future insecticide management strategies.” Researchers sequenced the genome of resistant and knockdown (either recovered or dead) mosquitoes after permethrin exposure using a bottle bioassay. The aim was to identify genomic variants/biomarkers associated with specific resistance mechanisms. Two common pyrethroid resistance mechanisms occur among […]
Posted in Mosquitoes, Permethrin, pyrethroids, Resistance, Synthetic Pyrethroids | No Comments »
03
Jun
(Beyond Pesticides, June 3, 2021) A report published in Royal Society Open Science finds pesticide-resistant parasitic lice (Lepeophtheirus salmonis) are endangering wild and farmed fish populations in the North Atlantic. Extensive use of pesticides to rid the parasite has led to widespread resistance to multiple pesticides, prompting increasing infection rates among North Atlantic salmon populations. Overexploitation of wild fish and other ocean organisms has depleted seafood stocks globally. Some fisheries market aquaculture practices, like fish/seafood farming, as a solution to overfishing. However, the aquaculture industry repeatedly faces sustainability issues and fails to adhere to environmental regulations that threaten marine health. The oceans are essential to human health and well-being, feeding billions, supporting millions of jobs, and supplying medicinal materials. However, environmental contaminants like pesticides have profound impact on the ecosystem and the inhabitants. Therefore, it is necessary to understand how pesticides can influence resistance among lethal pest populations, especially in ecologically vulnerable and highly interconnected ecosystems like ocean basins. The authors of the report caution, “These results demonstrate the speed to which this parasite can develop widespread multi-resistance, illustrating why the aquaculture industry has repeatedly lost the arms race with this highly problematic parasite.” Over the past two decades, organophosphate and pyrethroid insecticides […]
Posted in Aquaculture, Aquatic Organisms, fish, organophosphate, pyrethroids, Resistance, Water | No Comments »
08
Apr
(Beyond Pesticides, April 8, 2021) Pesticide use threatens aquatic and terrestrial invertebrates and plants more than ever, despite declining chemical use and implementation of genetically engineered (GE) crops in the U.S., according to a University Koblenz-Landau, Germany study. Since the publication of Rachel Carson’s Silent Spring (1962), many environmental agencies have banned the use of pesticides like organochlorines, organophosphates, and carbamates for their devastating toxic—sometimes lethal—effects, particularly on vertebrates, including humans. However, this ban created a pathway for a new generation of pesticides (e.g., neonicotinoids, pyrethroids) to take hold. Although these pesticides are more target-specific, requiring lower chemical concentrations for effectiveness, they have over double the toxic effects on invertebrates, like pollinators. Invertebrates and plants are vital for ecosystem function, offering various services, from decomposition to supporting the food web. Furthermore, invertebrates and plants can act as indicator species (bioindicators) that scientists can observe for the presence and impact of environmental changes and stressors. Therefore, reductions in invertebrate and plant life have implications for ecosystem health that can put human well-being at risk. Study lead author Ralf Schulz, PH.D., notes, “[This study] challenge[s] the claims of decreasing environmental impact of chemical pesticides in both conventional and GM [genetically modified or genetically engineered (GE)] crops and […]
Posted in Agriculture, Alternatives/Organics, Beneficials, Biodiversity, neonicotinoids, Pollinators, pyrethroids, Synthetic Pyrethroids, Wildlife/Endangered Sp. | 2 Comments »
