Emamectin

Emamectin is a semisynthetic derivative of abamectin, a natural avermectin. It is an insecticide and nematicide used to control a wide range of pests, including Lepidoptera, mites, and nematodes. Emamectin is produced by fermentation using a naturally occurring soil bacterium, Streptomyces avermitilis.

Chemistry

Emamectin is a mixture of two homologous components, B1a and B1b, which differ in the presence of a double bond. The B1a component is the more active of the two. Emamectin is soluble in water and most organic solvents. It is stable under normal storage conditions, but can degrade under strong acidic or alkaline conditions.

Mode of Action

Emamectin acts by stimulating the release of gamma-aminobutyric acid (GABA) in the nervous system of the pests. This leads to paralysis and death of the pest. It is highly toxic to insects and nematodes, but has low toxicity to mammals and birds.

Use in Agriculture

Emamectin is used in a variety of crops, including cotton, soybeans, corn, and potatoes. It is typically applied as a foliar spray, but can also be used as a soil treatment. Emamectin is effective against a wide range of pests, but is particularly effective against Lepidoptera, mites, and nematodes.

Environmental Impact

Emamectin is not highly persistent in the environment. It is rapidly degraded in soil and water, with a half-life of less than a day in water and up to 15 days in soil. Emamectin is highly toxic to aquatic organisms, but has low toxicity to birds and mammals.

Regulation

Emamectin is registered for use in many countries, including the United States, European Union, and Australia. It is classified as a restricted use pesticide in the United States due to its high toxicity to aquatic organisms.

See Also

• Abamectin
• Avermectin
• Insecticide
• Nematicide