ITHACA, N.Y. - Cornell University research offers a number of alternatives to neonicotinoids (neonics) that might work for farmers who grow large-seeded vegetable crops such as snap bean, dry bean and sweet corn. This class of insecticides has devastating ecological impacts, especially to pollinators, beneficial insects and aquatic invertebrates.
“We wanted to find other options for growers to protect their vegetable crops from major pests. The impetus was to identify new products including those in the registration pipeline,” said Brian Nault, professor of entomology. “My program has shifted in recent years and has focused on this major issue.”
The task has not been easy, he added. “Insecticides kill insects, so it’s a tall order to find those that kill the pests but have minimal effects on pollinators and other beneficial insects.”
The race to find alternatives to neonicotinoids is urgent, Nault said, because the Birds and Bees Protection Act in New York state is phasing out the sale, distribution or purchase of certain neonicotinoid-treated corn, soybean or wheat seeds starting in the next few years.
Research shows neonics have made U.S. agriculture more harmful to insects, and the Environmental Protection Agency determined that neonics likely jeopardize the continued existence of more than 200 threatened and endangered species.
The researchers conducted field studies from 2021 to 2024 across Delaware, Minnesota, New York, Washington and Wisconsin. They compared protection of vegetable crops from seedcorn maggot using standard neonicotinoid seed treatments, thiamethoxam and clothianidin, with non-neonicotinoid alternatives including spinosad, cyantraniliprole, chlorantraniliprole, isocycloseram and tetraniliprole. They also compared the risk of these alternative insecticides to workers, consumers and the environment using the Environmental Impact Quotient (EIQ) developed by Cornell University's Integrated Pest Management Program.
They found that cyantraniliprole and spinosad seed treatments in snap bean performed as well and occasionally better than the neonicotinoid standard, thiamethoxam. None of the alternative insecticide seed treatments in dry bean provided consistent and reliable protection against seedcorn maggot compared with neonics. But the big triumph was that five different alternative seed treatments (chlorantraniliprole, cyantraniliprole, isocycloseram, spinosad and tetraniliprole) proved as effective as standard neonics for sweet corn.
“Sweet corn is a pretty big crop in New York state,” Nault said. So there is good news about alternatives for sweet corn, less so for dry beans and snap beans, he said. For all of the alternative pesticides, their research shows, supplemental options may be necessary to cover additional pests.
“For many vegetable crops, farmers could replace the neonic at planting but may need another pesticide later in the season,” Nault said. Other important factors will need to be considered before adopting non-neonicotinoid alternative seed treatments. For example, many are not yet approved for commercial use on these specific crops, and the cost of these newer products will undoubtedly be more expensive than neonicotinoids.
For additional information, read this Cornell Chronicle story.
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Crop Protection