Knockdown resistance, also called kdr, describes cases of resistance to diphenylethane (e.g. DDT) and pyrethroid [1] insecticides in insects and other arthropods that result from reduced sensitivity of the nervous system caused by point mutations in the insect population's genetic makeup. Such mutative resistance is characterized by the presence of kdr alleles in the insect's genome. Knockdown resistance, first identified and characterized in the house fly ( Musca domestica ) in the 1950s, remains a threat to the continued usefulness of pyrethroids in the control of many pest species. Research since 1990 has provided a wealth of new information on the molecular basis of knockdown resistance. [2]
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 be a major factor behind the increase in the 20th-century's agricultural productivity. Nearly all insecticides have the potential to significantly alter ecosystems; many are toxic to humans and/or animals; some become concentrated as they spread along the food chain.
The Curculionidae are the family of the "true" weevils. They are one of the largest animal families, with 6,800 genera and 83,000 species described worldwide. They are the sister group to the family Brentidae.
Pesticide resistance describes the decreased susceptibility of a pest population to a pesticide that was previously effective at controlling the pest. Pest species evolve pesticide resistance via natural selection: the most resistant specimens survive and pass on their acquired heritable changes traits to their offspring. If a pest has resistance then the pesticide lacks efficacy – efficacy and resistance are inversely related.
Cypermethrin (CP) is a synthetic pyrethroid used as an insecticide in large-scale commercial agricultural applications as well as in consumer products for domestic purposes. It behaves as a fast-acting neurotoxin in insects. It is easily degraded on soil and plants but can be effective for weeks when applied to indoor inert surfaces. Exposure to sunlight, water and oxygen will accelerate its decomposition. Cypermethrin is highly toxic to fish, bees and aquatic insects, according to the National Pesticides Telecommunications Network (NPTN). It is found in many household ant and cockroach killers, including Raid, Ortho, Combat, and ant chalk.
The pyrethrins are a class of organic compounds normally derived from Chrysanthemum cinerariifolium that have potent insecticidal activity by targeting the nervous systems of insects. Pyrethrin naturally occurs in chrysanthemum flowers and is often considered an organic insecticide when it is not combined with piperonyl butoxide or other synthetic adjuvants. Their insecticidal and insect-repellent properties have been known and used for thousands of years.
Knockdown or knock-down may refer to:
A pyrethroid is an organic compound similar to the natural pyrethrins, which are produced by the flowers of pyrethrums. Pyrethroids are used as commercial and household insecticides.
Permethrin, sold under the brand name Nix, among others, is a medication and an insecticide. As a medication, it is used to treat scabies and lice. It is applied to the skin as a cream or lotion. As an insecticide, it can be sprayed onto clothing or mosquito nets to kill the insects that touch them.
Deltamethrin is a pyrethroid ester insecticide. Deltamethrin plays a key role in controlling malaria vectors, and is used in the manufacture of long-lasting insecticidal mosquito nets; however, resistance of mosquitos and bed bugs to deltamethrin is becoming widespread.
Tralomethrin is a pyrethroid insecticide.
Cyhalothrin is the ISO common name for an organic compound that, in specific isomeric forms, is used as a pesticide. It is a pyrethroid, a class of synthetic insecticides that mimic the structure and properties of the naturally occurring insecticide pyrethrin which is present in the flowers of Chrysanthemum cinerariifolium. Pyrethroids such as cyhalothrin are often preferred as an active ingredient in agricultural insecticides because they are more cost-effective and longer acting than natural pyrethrins. λ-and γ-cyhalothrin are now used to control insects and spider mites in crops including cotton, cereals, potatoes and vegetables.
Cyfluthrin is a pyrethroid insecticide and common household pesticide. It is a complex organic compound and the commercial product is sold as a mixture of isomers. Like most pyrethroids, it is highly toxic to fish and invertebrates, but it is far less toxic to humans. It is generally supplied as a 10–25% liquid concentrate for commercial use and is diluted prior to spraying onto agricultural crops and outbuildings.
Tuta absoluta is a species of moth in family Gelechiidae known by the common names South American tomato pinworm, tomato leafminer, tomato pinworm and South American tomato moth. It is well known as a serious pest of tomato crops in Europe, Africa, western Asia and South and Central America, with larvae causing up to 100% loss if not effectively controlled.
Bed bugs, or Cimicidae, are small parasitic insects. The term usually refers to species that prefer to feed on human blood.
Tefluthrin is the ISO common name for an organic compound that is used as a pesticide. It is a pyrethroid, a class of synthetic insecticides that mimic the structure and properties of the naturally occurring insecticide pyrethrin which is present in the flowers of Chrysanthemum cinerariifolium. Pyrethroids such as tefluthrin are often preferred as active ingredients in agricultural insecticides because they are more cost-effective and longer acting than natural pyrethrins. It is effective against soil pests because it can move as a vapour without irreversibly binding to soil particles: in this respect it differs from most other pyrethroids.
Janet Hemingway is a British entomologist, Professor of Insect Molecular Biology and Director of the Liverpool School of Tropical Medicine (LSTM). She also works on advocacy and resource mobilisation at the Innovative Vector Control Consortium (IVCC), and is International Director of the Joint Centre for Infectious Diseases Research, Jizan, Saudi Arabia. She is "the youngest woman to ever to become a full professor in the UK".
Fenpropathrin, or fenopropathrin, is a widely used pyrethroid insecticide in agriculture and household. Fenpropathrin is an ingestion and contact synthetic pyrethroid. Its mode of action is similar to other natural (pyrethrum) and synthetic pyrethroids where in they interfere with the kinetics of voltage gated sodium channels causing paralysis and death of the pest. Fenpropathrin was the first of the light-stable synthetic pyrethroids to be synthesized in 1971, but it was not commercialized until 1980. Like other pyrethroids with an α-cyano group, fenpropathrin also belongs to the termed type II pyrethroids. Type II pyrethroids are a more potent toxicant than type I in depolarizing insect nerves. Application rates of fenpropathrin in agriculture according to US environmental protection agency (EPA) varies by crop but is not to exceed 0.4 lb ai/acre.
Cytochrome P450, family 9, also known as CYP9, is a cytochrome P450 family found in Insect genome, CYP9 and insect CYP6 family belong to the same clan as mammalian CYP3 and CYP5 families. The first gene identified in this family is the CYP9A1 from the Heliothis virescens, which is involved in thiodicarb insecticide resistance. Subfamily CYP9A in Lepidopteran play important roles in insecticide resistance, can metabolize esfenvalerate efficiently.
Cytochrome P450, family 6, also known as CYP6, is a cytochrome P450 family found in Insect genome. CYP6 and CYP9, another insect CYP family, belong to the same clan as mammalian CYP3 and CYP5 families.