Recent bans in Europe are evidence of growing concerns about pesticide use and declining bee populations. The Environmental Protection Agency has identified more than 70 pesticides that are highly toxic to bees. Here are the main categories of pesticides linked to bee deaths and pollinator decline.
Neonicotinoids Neonicotinoids (neonics) are a class of insecticides whose general mechanism of action attacks the central nervous system of insects, causing paralysis and death. Research has shown that neonicotinoid residues can accumulate in the pollen and nectar of treated plants, posing a potential risk to pollinators. Because of this and their widespread use, there are serious concerns that neonicotinoids play a significant role in pollinator decline.
Neonicotinoid insecticides are also persistent in the environment and, when used as seed treatments, are transferred to pollen and nectar residues of treated plants. One seed is enough to kill a songbird. These pesticides can also pollute waterways and are highly toxic to aquatic life. The case of neonicotinoid pesticides illustrates two key problems with current pesticide registration processes and risk assessment methods: dependence on industry-funded scientific research that is inconsistent with peer-reviewed research, and the inadequacy of current risk assessment processes to account for the sublethal effects of pesticides.
Sulfoxaflor was first registered in 2013 and has generated much controversy. Suloxaflor is a new type of sulfenimide pesticide with chemical characteristics similar to neonicotinoid pesticides. Following the court’s decision, the U.S. Environmental Protection Agency (EPA) reregistered sulfenamide in 2016, limiting its use to reduce exposure to bees. But even if this reduces the sites of use and limits the time of use, the systemic toxicity of sulfoxaflor ensures that these measures will not adequately eliminate the use of this chemical. Pyrethroids have also been shown to impair the learning and foraging behavior of bees. Pyrethroids are often associated with bee mortality and have been found to significantly reduce bee fertility, reduce the rate at which bees develop into adults, and prolong their period of immaturity. Pyrethroids are widely found in pollen. Commonly used pyrethroids include bifenthrin, deltamethrin, cypermethrin, phenethrin, and permethrin. Widely used for indoor and lawn pest control, Fipronil is an insecticide that is highly toxic to insects. It is moderately toxic and has been associated with hormonal disturbances, thyroid cancer, neurotoxicity, and reproductive effects. Fipronil has been shown to reduce behavioral functioning and learning abilities in bees. Organophosphates. Organophosphates such as malathion and spikenard are used in mosquito control programs and can put bees at risk. Both are highly toxic to bees and other non-target organisms, and bee deaths have been reported with ultra-low toxicity sprays. Bees are indirectly exposed to these pesticides through residues left on plants and other surfaces after mosquito spraying. Pollen, wax and honey have been found to contain residues.
Post time: Sep-12-2023