Sulfoxaflor, also marketed as ''Isoclast'', is a systemic

insecticide Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to b ...

that acts as an

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

neurotoxin Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and mature ner ...

. A

pyridine Pyridine is a basic heterocyclic organic compound with the chemical formula . It is structurally related to benzene, with one methine group replaced by a nitrogen atom. It is a highly flammable, weakly alkaline, water-miscible liquid with a d ...

and a

trifluoromethyl The trifluoromethyl group is a functional group that has the formula -CF3. The naming of is group is derived from the methyl group (which has the formula -CH3), by replacing each hydrogen atom by a fluorine atom. Some common examples are trifluoro ...

compound, it is a member of a class of chemicals called

sulfoximine In chemistry, a sulfilimine (or sulfimide) is a type of chemical compound containing a sulfur-to-nitrogen bond which is often represented as a double bond (). In fact, a double bond violates the octet rule, and the bond may be considered a single ...

s, which act on the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all par ...

of insects.

Mechanism of action

Sulfoxaflor is a systemic insecticide, acts as a neurotoxin to affected insects, and kills through contact or ingestion. Sulfoxaflor is classified for use against sap-feeding insects as a

, which is a sub-group of insecticides that act as

nicotinic acetylcholine receptor Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the central and peripheral ne ...

(nAChR) competitive modulators. Sulfoxaflor binds to nAChRs in place of acetylcholine. Sulfoxaflor binding causes uncontrolled

nerve impulses An action potential occurs when the membrane potential of a specific cell location rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of animal cells, ...

resulting in muscle tremors followed by paralysis and death. Other nAChR competitive modulator sub-groups that bind differently on the receptor than sulfoximines include

neonicotinoids Neonicotinoids (sometimes shortened to neonics ) are a class of neuro-active insecticides chemically similar to nicotine, developed by scientists at Shell and Bayer in the 1980s. The neonicotinoid family includes acetamiprid, clothianidin, din ...

nicotine Nicotine is a natural product, naturally produced alkaloid in the nightshade family of plants (most predominantly in tobacco and ''Duboisia hopwoodii'') and is widely used recreational drug use, recreationally as a stimulant and anxiolytic. As ...

, and

butenolide Butenolides are a class of lactones with a four-carbon heterocyclic ring structure.Joule JA, Mills K. (2000). Heterocyclic Chemistry 4th ed. Blackwell Science Publishing: Oxford, UK They are sometimes considered oxidized derivatives of furan. The ...

s. Because sulfoxaflor binds much more strongly to insect neuron

receptors Receptor may refer to: *Sensory receptor, in physiology, any structure which, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds to a n ...

than to mammal neuron receptors, this

is selectively more toxic to insects than mammals.

Non-target effects

Application is only recommended when pollinators are not likely to be present in an area as sulfoxaflor is highly toxic to bees if they come into contact with spray droplets shortly after application; toxicity is reduced after the spray has dried.

Registration

On May 6, 2013, the

United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...

(EPA) approved the first two commercial pesticide products that contain sulfoxaflor, marketed under the brand names "Transform" and "Closer", to the Dow Chemical Corporation. On September 10, 2015 the U.S. 9th Circuit Court of Appeals overturned the EPA's approval of sulfoxaflor, citing insufficient evidence from studies regarding bee health to justify how sulfoxaflor was approved. Beekeepers and environmental groups supported the decision, saying that the EPA must assess the health of entire hives, not just individual bees. On October 14, 2016, the United States Environmental Protection Agency (EPA) approved new registrations for sulfoxaflor, "Transform" and "Closer", to the Dow Chemical Corporation. Previously, the Dow Chemical Corporation owned and sold these products. However, as of June, 2019, the agricultural wing of the Dow Chemical Corporation was split into an independent public corporation called

Corteva Agriscience Corteva, Inc. (also known as Corteva Agriscience) is a major American agricultural chemical and seed company that was the agricultural unit of DowDuPont prior to being spun off as an independent public company. DowDuPont announced the Corteva na ...

, who now sells the sulfoxaflor-based pesticides. On July 12, 2019, the EPA announced it will allow the use of sulfoxaflor, citing new studies that show lower harm levels to bees than other available pesticides. The EPA concluded that sulfoxaflor would lessen the danger to bees since industry-backed studies assessed it dissipated more quickly and required few applications than other pesticides. On December 21, 2022, the US 9th Circuit Court of Appeals ruled that the EPA broke the law in allowing new uses of sulfoxaflor because it failed to assess its risks to endangered species nor give the public a chance to comment on the decision. The court then ordered the EPA to allow the public 180 days to comment on expanding the uses of sulfoxaflor. Sulfoxaflor is currently registered in 47 countries, including US, Canada, Mexico, Argentina, Chile, India, China and Australia. The registration of Closer and Transform in France was overturned by a court decision in November, 2017. French court suspends two Dow pesticides over potential harm to bees
24 November 2017 ''reuters.com'', accessed 11 June 2019

References

External links

The EPA’s Final Decision on the New Active Ingredient SulfoxaflorDow AgroSciences Receives U.S. EPA Registration for Sulfoxaflor Dow AgroSciences Receives U.S. EPA Registration for Sulfoxaflor (Press release)
{{Insecticides Insecticides Pyridines Trifluoromethyl compounds Nitriles Sulfoximines

Mechanism of action

Non-target effects

Registration

See also

References

External links