Insecticides are substances used to kill

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 ...

s. They include ovicides and larvicides used against insect

eggs Humans and human ancestors have scavenged and eaten animal eggs for millions of years. Humans in Southeast Asia had domesticated chickens and harvested their eggs for food by 1,500 BCE. The most widely consumed eggs are those of fowl, especial ...

and

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. Th ...

e, respectively. Insecticides are used in

agriculture Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled peop ...

medicine Medicine is the science and Praxis (process), practice of caring for a patient, managing the diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, and Health promotion ...

, 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. Insecticides can be classified into two major groups: systemic insecticides, which have residual or long term activity; and contact insecticides, which have no residual activity. The

mode of action A mode of action (MoA) describes a functional or anatomical change, resulting from the exposure of a living organism to a substance. In comparison, a mechanism of action (MOA) describes such changes at the molecular level. A mode of action is impor ...

describes how the pesticide kills or inactivates a pest. It provides another way of classifying insecticides. Mode of action can be important in understanding whether an insecticide will be toxic to unrelated species, such as fish, birds and mammals. Insecticides may be repellent or non-repellent. Social insects such as ants cannot detect non-repellents and readily crawl through them. As they return to the nest they take insecticide with them and transfer it to their nestmates. Over time, this eliminates all of the ants including the queen. This is slower than some other methods, but usually completely eradicates the ant colony. Insecticides are distinct from non-insecticidal repellents, which repel but do not kill.

Type of activity

Systemic insecticides

Systemic insecticides become incorporated and distributed systemically throughout the whole plant. When insects feed on the plant, they ingest the insecticide. Systemic insecticides produced by

transgenic A transgene is a gene that has been transferred naturally, or by any of a number of genetic engineering techniques, from one organism to another. The introduction of a transgene, in a process known as transgenesis, has the potential to change the ...

plants are called plant-incorporated protectants (PIPs). For instance, a gene that codes for a specific ''

Bacillus thuringiensis ''Bacillus thuringiensis'' (or Bt) is a gram-positive, soil-dwelling bacterium, the most commonly used biological pesticide worldwide. ''B. thuringiensis'' also occurs naturally in the gut of caterpillars of various types of moths and butter ...

'' biocidal protein was introduced into corn (

maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn ( North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. ...

) and other species. The plant manufactures the protein, which kills the insect when consumed.

Contact insecticides

Contact insecticides are toxic to insects upon direct contact. These can be inorganic insecticides, which are metals and include the commonly used

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...

, and the less commonly used

arsenate The arsenate ion is . An arsenate (compound) is any compound that contains this ion. Arsenates are salts or esters of arsenic acid. The arsenic atom in arsenate has a valency of 5 and is also known as pentavalent arsenic or As(V). Arsenate r ...

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish ...

and fluorine compounds. Contact insecticides can also be organic insecticides, i.e. organic chemical compounds, synthetically produced, and comprising the largest numbers of pesticides used today. Or they can be natural compounds like pyrethrum, neem oil, etc. Contact insecticides usually have no residual activity. Efficacy can be related to the quality of

pesticide application Pesticide application refers to the practical way in which pesticides (including herbicides, fungicides, insecticides, or nematode control agents) are delivered to their ''biological targets'' (''e.g.'' pest organism, crop or other plant). ...

, with small droplets, such as

aerosol An aerosol is a suspension of fine solid particles or liquid droplets in air or another gas. Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog or mist, dust, forest exudates, and geyser steam. Examples of ant ...

s often improving performance.

Synthetic insecticides

Development

Organochlorides

The best known

organochloride An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one covalently bonded atom of chlorine. The chloroalkane class (alkanes with one or more hydrogens substituted by chlor ...

, DDT, was created by Swiss scientist Paul Müller. For this discovery, he was awarded the 1948

Nobel Prize for Physiology or Medicine The Nobel Prize in Physiology or Medicine ( sv, Nobelpriset i fysiologi eller medicin) is awarded yearly by the Nobel Assembly at the Karolinska Institute, Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or ...

. DDT was introduced in 1944. It functions by opening

sodium channel Sodium channels are integral membrane proteins that form ion channels, conducting sodium ions (Na+) through a cell's membrane. They belong to the superfamily of cation channels and can be classified according to the trigger that opens the channel ...

s in the insect's

nerve cell A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa. ...

s. The contemporaneous rise of the chemical industry facilitated large-scale production of DDT and related

chlorinated hydrocarbon An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one covalently bonded atom of chlorine. The chloroalkane class (alkanes with one or more hydrogens substituted by chlo ...

Organophosphates

Organophosphate In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered ...

s are another large class of contact insecticides. These also target the insect's nervous system. Organophosphates interfere with the

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...

acetylcholinesterase Acetylcholinesterase (HGNC symbol ACHE; EC 3.1.1.7; systematic name acetylcholine acetylhydrolase), also known as AChE, AChase or acetylhydrolase, is the primary cholinesterase in the body. It is an enzyme that catalyzes the breakdown of acety ...

and other

cholinesterase The enzyme cholinesterase (EC 3.1.1.8, choline esterase; systematic name acylcholine acylhydrolase) catalyses the hydrolysis of choline-based esters: : an acylcholine + H2O = choline + a carboxylate Several of these serve as neurotransmitters ...

s, disrupting nerve impulses and killing or disabling the insect. Organophosphate insecticides and

chemical warfare Chemical warfare (CW) involves using the toxic properties of chemical substances as weapons. This type of warfare is distinct from nuclear warfare, biological warfare and radiological warfare, which together make up CBRN, the military a ...

nerve agents (such as

sarin Sarin (NATO designation GB G-series, "B"">Nerve_agent#G-series.html" ;"title="hort for Nerve agent#G-series">G-series, "B" is an extremely toxic synthetic organophosphorus compound.tabun,

soman Soman (or GD, EA 1210, Zoman, PFMP, A-255, systematic name: ''O''-pinacolyl methylphosphonofluoridate) is an extremely toxic chemical substance. It is a nerve agent, interfering with normal functioning of the mammalian nervous system by inhibiti ...

, and VX) work in the same way. Organophosphates have a cumulative toxic effect to wildlife, so multiple exposures to the chemicals amplifies the toxicity. In the US, organophosphate use declined with the rise of substitutes.

Carbamates

Carbamate In organic chemistry, a carbamate is a category of organic compounds with the general formula and structure , which are formally derived from carbamic acid (). The term includes organic compounds (e.g., the ester ethyl carbamate), formall ...

insecticides have similar mechanisms to organophosphates, but have a much shorter duration of action and are somewhat less toxic.

Pyrethroids

Pyrethroid A pyrethroid is an organic compound similar to the natural pyrethrins, which are produced by the flowers of pyrethrums (''Chrysanthemum cinerariaefolium'' and '' C. coccineum''). Pyrethroids are used as commercial and household insecticides. In ...

pesticides mimic the insecticidal activity of the natural compound

pyrethrin 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 ...

, the biopesticide found in ''

Pyrethrum ''Pyrethrum'' was a genus of several Old World plants now classified as ''Chrysanthemum'' or '' Tanacetum'' which are cultivated as ornamentals for their showy flower heads. Pyrethrum continues to be used as a common name for plants formerly incl ...

'' (Now ''

Chrysanthemum Chrysanthemums (), sometimes called mums or chrysanths, are flowering plants of the genus ''Chrysanthemum'' in the family Asteraceae. They are native to East Asia and northeastern Europe. Most species originate from East Asia and the center ...

'' and ''

Tanacetum ''Tanacetum'' is a genus of about 160 species of flowering plants in the aster family, Asteraceae, native to many regions of the Northern Hemisphere.

'') species. These compounds are nonpersistent sodium channel modulators and are less toxic than organophosphates and carbamates. Compounds in this group are often applied against household pests.

Neonicotinoids

Neonicotinoid 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 ...

s are synthetic analogues of the natural insecticide nicotine (with much lower acute mammalian toxicity and greater field persistence). These chemicals are

acetylcholine Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Par ...

receptor

agonist An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...

s. They are broad-spectrum systemic insecticides, with rapid action (minutes-hours). They are applied as sprays, drenches, seed and

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former ...

treatments. Treated insects exhibit leg tremors, rapid wing motion, stylet withdrawal (

aphid Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A ...

s), disoriented movement, paralysis and death.

Imidacloprid Imidacloprid is a systemic insecticide belonging to a class of chemicals called the neonicotinoids which act on the central nervous system of insects. The chemical works by interfering with the transmission of stimuli in the insect nervous system ...

may be the most common. It has recently come under scrutiny for allegedly pernicious effects on

honeybee A honey bee (also spelled honeybee) is a eusocial flying insect within the genus ''Apis'' of the bee clade, all native to Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the current cos ...

s and its potential to increase the susceptibility of rice to

planthopper A planthopper is any insect in the infraorder Fulgoromorpha, in the suborder Auchenorrhyncha, a group exceeding 12,500 described species worldwide. The name comes from their remarkable resemblance to leaves and other plants of their environment ...

attacks.

Phenylpyrazoles

Phenylpyrazole insecticides Phenylpyrazole insecticides are a class of chemically-related broad-spectrum insecticides. The chemical structures of these insecticides are characterized by a central pyrazole ring with a phenyl group attached to one of the nitrogen atoms of the ...

, such as

fipronil Fipronil is a broad-spectrum insecticide that belongs to the phenylpyrazole chemical family. Fipronil disrupts the insect central nervous system by blocking the ligand-gated ion channel of the GABAA receptor and glutamate-gated chloride (GluCl ...

are a class of synthetic insecticides that operate by interfering with GABA receptors.

Butenolides

Butenolide pesticides are a novel group of chemicals, similar to neonicotinoids in their mode of action, that have so far only one representative:

flupyradifurone } Flupyradifurone is a systemic butenolide insecticide developed by Bayer CropScience under the name Sivanto. Flupyradifurone protects crops from sap-feeding pests such as aphids and is safer for non-target organisms compared to other insecticides. ...

. They are

receptor

s, like

neonicotinoid 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 ...

s, but with a different pharmacophore. They are broad-spectrum systemic insecticides, applied as sprays, drenches, seed and

treatments. Although the classic

risk assessment Broadly speaking, a risk assessment is the combined effort of: # identifying and analyzing potential (future) events that may negatively impact individuals, assets, and/or the environment (i.e. hazard analysis); and # making judgments "on the ...

considered this insecticide group (and flupyradifurone specifically) safe for

bee Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyly, monophyletic lineage within the ...

s, novel research has raised concern on their lethal and sublethal effects, alone or in combination with other chemicals or environmental factors.

Ryanoids/diamides

Diamides are synthetic ryanoid analogues with the same mode of action as ryanodine, a naturally occurring insecticide extracted from ''Ryania speciosa'' (

Salicaceae The Salicaceae is the willow family of flowering plants. The traditional family (Salicaceae ''sensu stricto'') included the willows, poplar, aspen, and cottonwoods. Genetic studies summarized by the Angiosperm Phylogeny Group (APG) have greatly ...

). They bind to

calcium channel A calcium channel is an ion channel which shows selective permeability to calcium ions. It is sometimes synonymous with voltage-gated calcium channel, although there are also ligand-gated calcium channels. Comparison tables The following tables ...

s in cardiac and skeletal muscle, blocking nerve transmission. The first insecticide from this class to be registered was Rynaxypyr, generic name chlorantraniliprole.

Insect growth regulators

Insect growth regulator An insect growth regulator (IGR) is a substance (chemical) that inhibits the life cycle of an insect. IGRs are typically used as insecticides to control populations of harmful insect pests such as cockroaches and fleas. Advantages Many IGRs are la ...

(IGR) is a term coined to include insect

hormone A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required ...

mimics and an earlier class of chemicals, the benzoylphenyl ureas, which inhibit

chitin Chitin ( C8 H13 O5 N)n ( ) is a long-chain polymer of ''N''-acetylglucosamine, an amide derivative of glucose. Chitin is probably the second most abundant polysaccharide in nature (behind only cellulose); an estimated 1 billion tons of chit ...

(exoskeleton) biosynthesis in insects

Diflubenzuron Diflubenzuron is an insecticide of the benzoylurea class. It is used in forest management and on field crops to selectively control insect pests, particularly forest tent caterpillar moths, boll weevils, gypsy moths, and other types of moths. ...

is a member of the latter class, used primarily to control

caterpillar Caterpillars ( ) are the larva, larval stage of members of the order Lepidoptera (the insect order comprising butterfly, butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawfly ...

s that are pests. The most successful insecticides in this class are the juvenoids ( juvenile hormone analogues). Of these, methoprene is most widely used. It has no observable acute toxicity in rats and is approved by

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level o ...

(WHO) for use in drinking water

cistern A cistern (Middle English ', from Latin ', from ', "box", from Greek ', "basket") is a waterproof receptacle for holding liquids, usually water. Cisterns are often built to catch and store rainwater. Cisterns are distinguished from wells by ...

s to combat

malaria Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or deat ...

. Most of its uses are to combat insects where the adult is the pest, including

mosquito Mosquitoes (or mosquitos) are members of a group of almost 3,600 species of small flies within the family Culicidae (from the Latin ''culex'' meaning "gnat"). The word "mosquito" (formed by ''mosca'' and diminutive ''-ito'') is Spanish for "lit ...

es, several fly species, and

flea Flea, the common name for the order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by ingesting the blood of their hosts. Adult fleas grow to about long, a ...

s. Two very similar products,

hydroprene Hydroprene is an insect growth regulator used as an insecticide. It is used against cockroaches, beetles, and moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with m ...

and kinoprene, are used for controlling species such as

cockroach Cockroaches (or roaches) are a Paraphyly, paraphyletic group of insects belonging to Blattodea, containing all members of the group except termites. About 30 cockroach species out of 4,600 are associated with human habitats. Some species are we ...

es and

white flies Whiteflies are Hemipterans that typically feed on the undersides of plant leaves. They comprise the family Aleyrodidae, the only family in the superfamily Aleyrodoidea. More than 1550 species have been described. Description and taxonomy The ...

. Methoprene was registered with the EPA in 1975. Virtually no reports of resistance have been filed. A more recent type of IGR is the

ecdysone Ecdysone is a prohormone of the major insect molting hormone 20-hydroxyecdysone, which is secreted from the prothoracic glands. It is of steroidal structure. Insect molting hormones (ecdysone and its homologues) are generally called ecdysteroid ...

agonist tebufenozide (MIMIC), which is used in

forestry Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forests, woodlands, and associated resources for human and environmental benefits. Forestry is practiced in plantations and natural stands. ...

and other applications for control of caterpillars, which are far more sensitive to its hormonal effects than other insect orders.

Biological pesticides

More natural insecticides have been interesting targets of research for two main reasons, firstly because the most common chemicals are losing effectiveness, and secondly due to their toxic effects upon the environment. Many organic compounds are already produced by plants for the purpose of defending the host plant from predation, and can be turned toward human ends. Four extracts of plants are in commercial use:

pyrethrum ''Pyrethrum'' was a genus of several Old World plants now classified as ''Chrysanthemum'' or '' Tanacetum'' which are cultivated as ornamentals for their showy flower heads. Pyrethrum continues to be used as a common name for plants formerly incl ...

rotenone Rotenone is an odorless, colorless, crystalline isoflavone used as a broad-spectrum insecticide, piscicide, and pesticide. It occurs naturally in the seeds and stems of several plants, such as the jicama vine plant, and the roots of several member ...

, neem oil, and various essential oils A trivial case is tree rosin, which is a natural insecticide. Specifically, the production of oleoresin by conifer species is a component of the defense response against insect attack and fungal

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a ger ...

infection. Many fragrances, e.g. oil of wintergreen, are in fact antifeedants.

Other biological approaches

Plant-incorporated protectants

= ''Bacillus thuringiensis''

= Transgenic crops that act as insecticides began in 1996 with a

genetically modified potato A genetically modified potato is a potato that has had its genes modified, using genetic engineering. Goals of modification include introducing pest resistance, tweaking the amounts of certain chemicals produced by the plant, and to prevent b ...

that produced Cry proteins, derived from the bacterium ''

'', which is toxic to beetle

larvae A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. T ...

such as the

Colorado potato beetle The Colorado potato beetle (''Leptinotarsa decemlineata''), also known as the Colorado beetle, the ten-striped spearman, the ten-lined potato beetle, or the potato bug, is a major pest of potato crops. It is about long, with a bright yellow/or ...

= RNA interference

= The technique has been expanded to include the use of RNAi insecticides which fatally

silence Silence is the absence of ambient audible sound, the emission of sounds of such low intensity that they do not draw attention to themselves, or the state of having ceased to produce sounds; this latter sense can be extended to apply to the c ...

crucial insect genes. (RNAi likely originally evolved as a defense against

virus A virus is a wikt:submicroscopic, submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and ...

es.) This was first demonstrated by Baum et al 2007, who incorporated a

V-APTase Vacuolar-type ATPase (V-ATPase) is a highly conserved evolutionarily ancient enzyme with remarkably diverse functions in eukaryotic organisms. V-ATPases acidify a wide array of intracellular organelles and pumps protons across the plasma ...

as a protectant into transgenic ''Zea mays'' and demonstrated effectiveness against ''

Diabrotica virgifera virgifera The Western corn rootworm, ''Diabrotica virgifera virgifera'', is one of the most devastating corn rootworm species in North America, especially in the midwestern corn-growing areas such as Iowa. A related species, the Northern corn rootworm, ''D ...

''. This suggests oral delivery against

Coleoptera Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

as a whole will probably be effective. Similar studies have followed Baum's technique to protect with dsRNAs targeting detox, especially insect P450s. Bolognesi et al 2012 is one of these following studies, however they found dsRNA to be processed into

siRNA Small interfering RNA (siRNA), sometimes known as short interfering RNA or silencing RNA, is a class of double-stranded RNA at first non-coding RNA molecules, typically 20-24 (normally 21) base pairs in length, similar to miRNA, and operating ...

s by the plants (in this case ''

Solanum tuberosum The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae. Wild potato species can be found from the southern United ...

'') themselves, and siRNAs to be less effectively taken up by insect cells. Bolognesi therefore produced additional transgenic ''S. tuberosum'' plants which instead produced ''longer'' dsRNAs ''in the

chloroplast A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it ...

s'', which naturally accumulate dsRNAs but do not have the machinery to convert them to siRNAs. Midgut cells in many larvae take up the molecules and help spread the signal. The technology can target only insects that have the silenced sequence, as was demonstrated when a particular RNAi affected only one of four

fruit fly Fruit fly may refer to: Organisms * Drosophilidae, a family of small flies, including: ** ''Drosophila'', the genus of small fruit flies and vinegar flies ** ''Drosophila melanogaster'' or common fruit fly ** '' Drosophila suzukii'' or Asian fruit ...

species. The technique is expected to replace many other insecticides, which are losing effectiveness due to the spread of insecticide resistance.

= Venom

= Spider venom peptide

fraction A fraction (from la, fractus, "broken") represents a part of a whole or, more generally, any number of equal parts. When spoken in everyday English, a fraction describes how many parts of a certain size there are, for example, one-half, eight ...

s are another class of potential transgenic traits which could expand the

repertoire and help to answer the resistance question.

Enzymes

Many plants exude substances to repel insects. Premier examples are substances activated by the

myrosinase Myrosinase (, ''thioglucoside glucohydrolase'', ''sinigrinase'', and ''sinigrase'') is a family of enzymes involved in plant defense against herbivores, specifically the mustard oil bomb. The three-dimensional structure has been elucidated and is ...

. This enzyme converts

glucosinolate Glucosinolates are natural components of many pungent plants such as mustard, cabbage, and horseradish. The pungency of those plants is due to mustard oils produced from glucosinolates when the plant material is chewed, cut, or otherwise damage ...

s to various compounds that are toxic to

herbivorous A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

insects. One product of this enzyme is allyl isothiocyanate, the pungent ingredient in horseradish sauces. Myrosinase general mechanism

The myrosinase is released only upon crushing the flesh of horseradish. Since allyl isothiocyanate is harmful to the plant as well as the insect, it is stored in the harmless form of the glucosinolate, separate from the myrosinase enzyme.

Bacterial

'' is a bacterial disease that affects Lepidopterans and some other insects. Toxins produced by strains of this bacterium are used as a

larvicide A larvicide (alternatively larvacide) is an insecticide that is specifically targeted against the larval life stage of an insect. Their most common use is against mosquitoes. Larvicides may be contact poisons, stomach poisons, growth regulators, ...

against

s, beetles, and mosquitoes. Toxins from '' Saccharopolyspora spinosa'' are isolated from fermentations and sold as Spinosad. Because these toxins have little effect on other

organism In biology, an organism () is any life, living system that functions as an individual entity. All organisms are composed of cells (cell theory). Organisms are classified by taxonomy (biology), taxonomy into groups such as Multicellular o ...

s, they are considered more

environmentally friendly Environment friendly processes, or environmental-friendly processes (also referred to as eco-friendly, nature-friendly, and green), are sustainability and marketing terms referring to goods and services, laws, guidelines and policies that cl ...

than synthetic pesticides. The toxin from ''B. thuringiensis'' ( Bt toxin) has been incorporated directly into plants through the use of

genetic engineering Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of technologies used to change the genetic makeup of cells, including ...

Other

Other biological insecticides include products based on entomopathogenic fungi (e.g., '' Beauveria bassiana'', ''

Metarhizium anisopliae ''Metarhizium robertsii'' formerly known as ''M. anisopliae'', and even earlier as ''Entomophthora anisopliae'' (basionym) is a fungus that grows naturally in soils throughout the world and causes disease in various insects by acting as a para ...

''), nematodes (e.g., ''

Steinernema feltiae Steinernema is a genus of nematodes in the family of Steinernematidae. The genus ''Steinernema'' is named after the nematologist Gotthold Steiner. Life cycle Species form symbiotic relationships with ''Xenorhabdus'' and ''Photorhabdus'' bact ...

'') and

es (e.g., '' Cydia pomonella'' granulovirus).

Synthetic insecticide and natural insecticides

A major emphasis of organic chemistry is the development of chemical tools to enhance agricultural productivity. Insecticides represent a major area of emphasis. Many of the major insecticides are inspired by biological analogues. Many others are not found in nature.

Environmental harm

Effects on nontarget species

Some insecticides kill or harm other creatures in addition to those they are intended to kill. For example, birds may be poisoned when they eat food that was recently sprayed with insecticides or when they mistake an insecticide granule on the ground for food and eat it.Palmer, WE, Bromley, PT, and Brandenburg, RL
Wildlife & pesticides - Peanuts
North Carolina Cooperative Extension Service. Retrieved on 14 October 2007. Sprayed insecticide may drift from the area to which it is applied and into wildlife areas, especially when it is sprayed aerially.

DDT

The development of DDT was motivated by desire to replace more dangerous or less effective alternatives. DDT was introduced to replace

lead Lead is a chemical element with the Symbol (chemistry), symbol Pb (from the Latin ) and atomic number 82. It is a heavy metals, heavy metal that is density, denser than most common materials. Lead is Mohs scale of mineral hardness#Intermediate ...

and

arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, bu ...

-based compounds, which were in widespread use in the early 1940s. DDT was brought to public attention by

Rachel Carson Rachel Louise Carson (May 27, 1907 – April 14, 1964) was an American marine biologist, writer, and conservation movement, conservationist whose influential book ''Silent Spring'' (1962) and other writings are credited with advancing the ...

's book ''

Silent Spring ''Silent Spring'' is an environmental science book by Rachel Carson. Published on September 27, 1962, the book documented the environmental harm caused by the indiscriminate use of pesticides. Carson accused the chemical industry of spreading d ...

''. One side-effect of DDT is to reduce the thickness of shells on the eggs of predatory birds. The shells sometimes become too thin to be viable, reducing bird populations. This occurs with DDT and related compounds due to the process of

bioaccumulation Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance at a rate faster than that at which the substance is lost or eliminated ...

, wherein the chemical, due to its stability and fat solubility, accumulates in organisms' fatty tissues. Also, DDT may

biomagnify Biomagnification, also known as bioamplification or biological magnification, is any concentration of a toxin, such as pesticides, in the tissues of tolerant organisms at successively higher levels in a food chain. This increase can occur as a ...

, which causes progressively higher concentrations in the body fat of animals farther up the

food chain A food chain is a linear network of links in a food web starting from producer organisms (such as grass or algae which produce their own food via photosynthesis) and ending at an apex predator species (like grizzly bears or killer whales), d ...

. The near-worldwide ban on agricultural use of DDT and related chemicals has allowed some of these birds, such as the

peregrine falcon The peregrine falcon (''Falco peregrinus''), also known as the peregrine, and historically as the duck hawk in North America, is a cosmopolitan bird of prey ( raptor) in the family Falconidae. A large, crow-sized falcon, it has a blue-grey ...

, to recover in recent years. A number of

organochlorine An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one covalently bonded atom of chlorine. The chloroalkane class (alkanes with one or more hydrogens substituted by chlor ...

pesticides have been banned from most uses worldwide. Globally they are controlled via the

Stockholm Convention Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed on 22 May 2001 in Stockholm and effective from 17 May 2004, that aims to eliminate or restrict the production and use of persistent organ ...

persistent organic pollutant Persistent organic pollutants (POPs), sometimes known as "forever chemicals", are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. They are toxic chemicals that adverse ...

s. These include:

aldrin Aldrin is an organochlorine insecticide that was widely used until the 1990s, when it was banned in most countries. Aldrin is a member of the so-called "classic organochlorines" (COC) group of pesticides. COCs enjoyed a very sharp rise in popula ...

chlordane Chlordane, or chlordan, is an organochlorine compound that was used as a pesticide. It is a white solid. In the United States, chlordane was used for termite-treatment of approximately 30 million homes until it was banned in 1988. Chlordane was ...

, DDT,

dieldrin Dieldrin is an organochloride originally produced in 1948 by J. Hyman & Co, Denver, as an insecticide. Dieldrin is closely related to aldrin, which reacts further to form dieldrin. Aldrin is not toxic to insects; it is oxidized in the insect to f ...

endrin Endrin is an organochloride with the chemical formula C12H8Cl6O that was first produced in 1950 by Shell and Velsicol Chemical Corporation. It was primarily used as an insecticide, as well as a rodenticide and piscicide. It is a colourless, od ...

heptachlor Heptachlor is an organochlorine compound that was used as an insecticide. Usually sold as a white or tan powder, heptachlor is one of the cyclodiene insecticides. In 1962, Rachel Carson's '' Silent Spring'' questioned the safety of heptachlor ...

, mirex and toxaphene.

Runoff and Percolation

Solid bait and liquid insecticides, especially if improperly applied in a location, get moved by water flow. Often, this happens through nonpoint sources where runoff carries insecticides in to larger bodies of water. As snow melts and rainfall moves over and through the ground, the water picks applied insecticides and deposits them in to larger bodies of water, rivers, wetlands, underground sources of previously potable water, and percolates in to watersheds. This runoff and percolation of insecticides can effect the quality of water sources, harming the natural ecology and thus, indirectly effect human populations through biomagnification and bioaccumulation.

Pollinator decline

Insecticides can kill bees and may be a cause of

pollinator decline Pollinator decline is the reduction in abundance of insect and other animal pollinators in many ecosystems worldwide that began being recorded at the end of the 20th century. Multiple lines of evidence exist for the reduction of wild pollinator ...

, the loss of bees that pollinate plants, and

colony collapse disorder Colony collapse disorder (CCD) is an abnormal phenomenon that occurs when the majority of worker bees in a honey bee colony disappear, leaving behind a queen, plenty of food, and a few nurse bees to care for the remaining immature bees. Whi ...

(CCD), in which worker bees from a

beehive A beehive is an enclosed structure in which some honey bee species of the subgenus ''Apis'' live and raise their young. Though the word ''beehive'' is commonly used to describe the nest of any bee colony, scientific and professional literature ...

Western honey bee The western honey bee or European honey bee (''Apis mellifera'') is the most common of the 7–12 species of honey bees worldwide. The genus name ''Apis'' is Latin for "bee", and ''mellifera'' is the Latin for "honey-bearing" or "honey carrying", ...

colony abruptly disappear. Loss of pollinators means a reduction in

crop yield In agriculture, the yield is a measurement of the amount of a crop grown, or product such as wool, meat or milk produced, per unit area of land. The seed ratio is another way of calculating yields. Innovations, such as the use of fertilizer, the c ...

s. Sublethal doses of insecticides (i.e. imidacloprid and other neonicotinoids) affect bee foraging behavior. However, research into the causes of CCD was inconclusive as of June 2007.

Bird decline

Besides the effects of direct consumption of insecticides, populations of insectivorous birds decline due to the collapse of their prey populations. Spraying of especially wheat and corn in Europe is believed to have caused an 80 per cent decline in flying insects, which in turn has reduced local bird populations by one to two thirds.

Alternatives

Instead of using chemical insecticides to avoid crop damage caused by insects, there are many alternative options available now that can protect farmers from major economic losses. Some of them are: #

Breeding Breeding is sexual reproduction that produces offspring, usually animals or plants. It can only occur between a male and a female animal or plant. Breeding may refer to: * Animal husbandry, through selected specimens such as dogs, horses, and rab ...

crops resistant, or at least less susceptible, to pest attacks. # Releasing predators, parasitoids, or

s to control pest populations as a form of

biological control Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically als ...

. # Chemical control like releasing

pheromone A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...

s into the field to confuse the insects into not being able to find mates and reproduce. #

Integrated Pest Management Integrated pest management (IPM), also known as integrated pest control (IPC) is a broad-based approach that integrates both chemical and non-chemical practices for economic control of pests. IPM aims to suppress pest populations below the eco ...

: using multiple techniques in tandem to achieve optimal results. # Push-pull technique: intercropping with a "push" crop that repels the pest, and planting a "pull" crop on the boundary that attracts and traps it.

Examples

Organochloride An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one covalently bonded atom of chlorine. The chloroalkane class (alkanes with one or more hydrogens substituted by chlor ...
s

Aldrin Aldrin is an organochlorine insecticide that was widely used until the 1990s, when it was banned in most countries. Aldrin is a member of the so-called "classic organochlorines" (COC) group of pesticides. COCs enjoyed a very sharp rise in popula ...

Chlordane Chlordane, or chlordan, is an organochlorine compound that was used as a pesticide. It is a white solid. In the United States, chlordane was used for termite-treatment of approximately 30 million homes until it was banned in 1988. Chlordane was ...

* Chlordecone * DDT *

Dieldrin Dieldrin is an organochloride originally produced in 1948 by J. Hyman & Co, Denver, as an insecticide. Dieldrin is closely related to aldrin, which reacts further to form dieldrin. Aldrin is not toxic to insects; it is oxidized in the insect to f ...

* Endosulfan *

Endrin Endrin is an organochloride with the chemical formula C12H8Cl6O that was first produced in 1950 by Shell and Velsicol Chemical Corporation. It was primarily used as an insecticide, as well as a rodenticide and piscicide. It is a colourless, od ...

Heptachlor Heptachlor is an organochlorine compound that was used as an insecticide. Usually sold as a white or tan powder, heptachlor is one of the cyclodiene insecticides. In 1962, Rachel Carson's '' Silent Spring'' questioned the safety of heptachlor ...

Hexachlorobenzene Hexachlorobenzene, or perchlorobenzene, is an organochloride with the molecular formula C6Cl6. It is a fungicide formerly used as a seed treatment, especially on wheat to control the fungal disease bunt. It has been banned globally under the Sto ...

Lindane Lindane, also known as ''gamma''-hexachlorocyclohexane (γ-HCH), gammaxene, Gammallin and benzene hexachloride (BHC), is an organochlorine chemical and an isomer of hexachlorocyclohexane that has been used both as an agricultural insecticide and ...

(gamma-hexachlorocyclohexane) * Methoxychlor * Mirex *

Pentachlorophenol Pentachlorophenol (PCP) is an organochlorine compound used as a pesticide and a disinfectant. First produced in the 1930s, it is marketed under many trade names. It can be found as pure PCP, or as the sodium salt of PCP, the latter of which dis ...

* TDE

Organophosphate In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered ...
s

* Acephate * Azinphos-methyl * Bensulide * Chlorethoxyfos *

Chlorpyrifos Chlorpyrifos (CPS), also known as Chlorpyrifos ethyl, is an organophosphate pesticide that has been used on crops, animals, and buildings, and in other settings, to kill several pests, including insects and worms. It acts on the nervous systems ...

Chlorpyriphos-methyl Chlorpyrifos (CPS), also known as Chlorpyrifos ethyl, is an organophosphate pesticide that has been used on crops, animals, and buildings, and in other settings, to kill several pests, including insects and worms. It acts on the nervous systems ...

Diazinon Diazinon (IUPAC name: ''O'',''O''-Diethyl ''O''- -methyl-6-(propan-2-yl)pyrimidin-2-ylphosphorothioate, INN - Dimpylate), a colorless to dark brown liquid, is a thiophosphoric acid ester developed in 1952 by Ciba-Geigy, a Swiss chemical company ( ...

* Dichlorvos (DDVP) *

Dicrotophos Dicrotophos is an organophosphate acetylcholinesterase inhibitor used as an insecticide Insecticides are substances used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides a ...

* Dimethoate * Disulfoton * Ethoprop * Fenamiphos * Fenitrothion *

Fenthion Fenthion is an organothiophosphate insecticide, avicide, and acaricide. Like most other organophosphates, its mode of action is via cholinesterase inhibition. Due to its relatively low toxicity towards humans and mammals, fenthion is listed as ...

* Fosthiazate *

Malathion Malathion is an organophosphate insecticide which acts as an acetylcholinesterase inhibitor. In the USSR, it was known as carbophos, in New Zealand and Australia as maldison and in South Africa as mercaptothion. Pesticide use Malathion is a pe ...

Methamidophos Methamidophos, trade name "Monitor," is an organophosphate insecticide. Crops grown with the use of methamidophos include potatoes and some Latin American rice. Many nations have used methamidophos on crops, including developed nations such as Sp ...

Methidathion Methidathion is an organophosphate insecticide; its use is banned in the European Union and USA. Methidathion has been used as an insecticide in many countries to control caterpillars of '' Indarbela quadrinotata''. In 2012, residues were foun ...

* Mevinphos *

Monocrotophos Monocrotophos is an organophosphate insecticide. It is acutely toxic to birds and humans, so it has been banned in the U.S., the E.U., India and many other countries. Uses Monocrotophos is principally used in agriculture, as a relatively cheap ...

* Naled *

Omethoate Omethoate (C5H12NO4PS) is a systemic organophosphorous insecticide and acaricide available as a soluble concentrate. It is used to control insects and mites in horticulture and agriculture, as well as in the home garden. It is an irritant to the ...

Oxydemeton-methyl Oxydemeton-methyl is an organothiophosphate insecticide. It is primarily used to control aphids, mites, and thrip Thrips (order Thysanoptera) are minute (mostly long or less), slender insects with fringed wings and unique asymmetrical mou ...

Parathion Parathion, also called parathion-ethyl or diethyl parathion and locally known as "Folidol", is an organophosphate insecticide and acaricide. It was originally developed by IG Farben in the 1940s. It is highly toxic to non-target organisms, inc ...

Parathion-methyl Parathion methyl, or methyl parathion, is an organophosphate insecticide, possessing an organothiophosphate group. It is structurally very similar to parathion-ethyl. It is not allowed for sale and import in nearly all countries around the worl ...

* Phorate * Phosalone *

Phosmet Phosmet is a phthalimide-derived, non-systemic, organophosphate insecticide used on plants and animals. It is mainly used on apple trees for control of codling moth, though it is also used on a wide range of fruit crops, ornamentals, and vines fo ...

Phostebupirim Tebupirimfos, also known as phostebupirim, is an organothiophosphate insecticide. It is used on corn Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), ...

Phoxim Phoxim is an organophosphate insecticide that is produced by the Bayer Bayer AG (, commonly pronounced ; ) is a German multinational corporation, multinational pharmaceutical and biotechnology company and one of the largest pharmaceutical c ...

Pirimiphos-methyl Pirimiphos-methyl, marketed as Actellic, and Sybol is a phosphorothioate used as an insecticide. It was originally developed by Imperial Chemical Industries Ltd., now Syngenta, at their Jealott's Hill Jealott's Hill is a village in the cou ...

Profenofos Profenofos is an organophosphate insecticide. It is a liquid with a pale yellow to amber color and a garlic-like odor. It was first registered in the United States in 1982. As of 2015, it was not approved in the European Union. Uses Profenof ...

* Terbufos *

Tetrachlorvinphos Tetrachlorvinphos is an organophosphate insecticide used to kill fleas and ticks. History Tetrachlorvinphos was initially registered for use in the United States in 1966 by the U.S. Department of Agriculture. Tetrachlorvinphos was originally re ...

* Tribufos * Trichlorfon

Carbamate In organic chemistry, a carbamate is a category of organic compounds with the general formula and structure , which are formally derived from carbamic acid (). The term includes organic compounds (e.g., the ester ethyl carbamate), formall ...
s

* Aldicarb *

Bendiocarb Bendiocarb is an acutely toxic carbamate insecticide used in public health and agriculture and is effective against a wide range of nuisance and disease vector insects. Many bendiocarb products are or were sold under the tradenames "Ficam" and "T ...

Carbofuran Carbofuran is a carbamate pesticide, widely used around the world to control insects on a wide variety of field crops, including potatoes, corn and soybeans. It is a systemic insecticide, which means that the plant absorbs it through the roots ...

* Carbaryl * Dioxacarb * Fenobucarb *

Fenoxycarb Fenoxycarb is a carbamate insect growth regulator. It has a low toxicity for bees, birds, and humans, but is toxic to fish. The oral LD50 for rats is greater than . Fenoxycarb is non-neurotoxic and does not have the same mode of action as other ...

* Isoprocarb * Methomyl * Oxamyl * Propoxur *

2-(1-Methylpropyl)phenyl methylcarbamate Fenobucarb is a carbamate insecticide, also widely known as BPMC. A pale yellow or pale red liquid, insoluble in water; used as an agricultural insecticide, especially for control of Hemipteran pests, on rice and cotton Cotton is a soft, f ...

Pyrethroid A pyrethroid is an organic compound similar to the natural pyrethrins, which are produced by the flowers of pyrethrums (''Chrysanthemum cinerariaefolium'' and '' C. coccineum''). Pyrethroids are used as commercial and household insecticides. In ...
s

Allethrin The allethrins are a group of related synthetic compounds used in insecticides. They are classified as pyrethroids, i.e. synthetic versions of pyrethrin, a chemical with insecticidal properties found naturally in ''Chrysanthemum'' flowers. They we ...

* Bifenthrin * Cyhalothrin, Lambda-cyhalothrin *

Cypermethrin 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 degrad ...

Cyfluthrin 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 (MoA 3a), it is highly toxic to fish and invertebrates, but ...

* Deltamethrin * Etofenprox * Fenvalerate *

Permethrin Permethrin 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 tha ...

* Phenothrin *

Prallethrin Prallethrin is a pyrethroid insecticide. Prallethrin 1.6% w/w liquid vaporizer is a repellent insecticide which is generally used for the control of mosquitoes in the household. Products It is marketed as a mosquito repellent by Godrej as "Go ...

* Resmethrin * Tetramethrin * Tralomethrin *

Transfluthrin Transfluthrin is a fast-acting pyrethroid insecticide with low persistency. It has the molecular formula C15H12Cl2F4O2. Transfluthrin can be used in the indoor environment against flies, mosquitoes, moths and cockroaches. It is a relatively vo ...

Neonicotinoid 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 ...
s

* Acetamiprid * Clothianidin *

Dinotefuran Dinotefuran is an insecticide of the neonicotinoid class developed by Mitsui Chemicals for control of insect pests such as aphids, whiteflies, thrips, leafhoppers, leafminers, sawflies, mole cricket, white grubs, lacebugs, billbugs, be ...

Nithiazine Nithiazine is a nitromethylene neonicotinoid insecticide. It is irritating to the eyes and skin, and is moderately toxic to mammals. Nithiazine does not act as an acetylcholinesterase inhibitor Acetylcholinesterase inhibitors (AChEIs) als ...

* Thiacloprid *

Thiamethoxam Thiamethoxam is the ISO common name for a mixture of ''cis-trans'' isomers used as a systemic insecticide of the neonicotinoid class. It has a broad spectrum of activity against many types of insects and can be used as a seed dressing. Histo ...

Ryanoids

* Chlorantraniliprole * Cyantraniliprole * Flubendiamide

Insect growth regulators

* Benzoylureas **

Flufenoxuron Flufenoxuron is an insecticide that belongs to the benzoylurea chitin synthesis inhibitor group, which also includes diflubenzuron, triflumuron, and lufenuron. Flufenoxuron is a white crystalline powder. It is insoluble in water, is not flamm ...

Cyromazine Cyromazine is a triazine insect growth regulator used as an insecticide. It is a cyclopropyl derivative of melamine. Cyromazine works by affecting the nervous system of the immature larval stages of certain insects.Methoprene *

Hydroprene Hydroprene is an insect growth regulator used as an insecticide. It is used against cockroaches, beetles, and moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with m ...

* Tebufenozide

Derived from plants or microbes

Anabasine Anabasine is a pyridine and piperidine alkaloid found in the Tree Tobacco ('' Nicotiana glauca'') plant, a close relative of the common tobacco plant (''Nicotiana tabacum''). It is a structural isomer of, and chemically similar to, nicotine. It ...

Anethole Anethole (also known as anise camphor) is an organic compound that is widely used as a flavoring substance. It is a derivative of phenylpropene, a type of aromatic compound that occurs widely in nature, in essential oils. It is in the class of ph ...

(mosquito larvae) * Annonin *

Asimina ''Asimina'' is a genus of small trees or shrubs described as a genus in 1763. ''Asimina'' is the only temperate genus in the tropical and subtropical flowering plant family, Annonaceae. ''Asimina'' has large simple leaves and large fruit. It ...

(pawpaw tree seeds) for

lice Louse ( : lice) is the common name for any member of the clade Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera has variously been recognized as an order, infraorder, or a parvorder, as a resul ...

* Azadirachtin *

Caffeine Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is mainly used recreationally as a cognitive enhancer, increasing alertness and attentional performance. Caffeine acts by blocking binding of adenosine t ...

Carapa ''Carapa'' is a genus of flowering plants in the mahogany family, Meliaceae. These are trees up to 30 meters tall occurring in tropical South America, Central America,Hogan, C. M. 2008Isthmian-Atlantic moist forests.Encyclopedia of Earth, World ...

Cinnamaldehyde Cinnamaldehyde is an organic compound with the formula(C9H8O) C6H5CH=CHCHO. Occurring naturally as predominantly the ''trans'' (''E'') isomer, it gives cinnamon its flavor and odor. It is a phenylpropanoid that is naturally synthesized by the s ...

(very effective for killing mosquito larvae) * Cinnamon leaf oil (very effective for killing mosquito larvae) * Cinnamyl acetate (kills mosquito larvae) *

Citral Citral is an acyclic monoterpene aldehyde, and being a monoterpene, it is made of two isoprene units. Citral is a collective term which covers two geometric isomers that have their own separate names; the ''E''-isomer is named geranial (''trans' ...

* Citronellol * Deguelin * Derris (active ingredient is

) * ''

Desmodium caudatum ''Ohwia caudata'', formerly placed in the genus ''Desmodium'' (as ''D. caudatum''), is a deciduous nitrogen fixing plant in the family Fabaceae. It is found in India, China, Taiwan and other parts of Asia Asia (, ) is one of the worl ...

'' (leaves and roots) *

Eucalyptol Eucalyptol is a monoterpenoid. A colorless liquid, it is a bicyclic ether. Eucalyptol has a fresh mint-like smell and a spicy, cooling taste. It is insoluble in water, but miscible with organic solvents. Eucalyptol makes up ~70% - 90% of euc ...

Eugenol Eugenol is an allyl chain-substituted guaiacol, a member of the allylbenzene class of chemical compounds. It is a colorless to pale yellow, aromatic oily liquid extracted from certain essential oils especially from clove, nutmeg, cinnamon, ...

(mosquito larvae) * Hinokitiol *

Ivermectin Ivermectin (, '' EYE-vər-MEK-tin'') is an antiparasitic drug. After its discovery in 1975, its first uses were in veterinary medicine to prevent and treat heartworm and acariasis. Approved for human use in 1987, today it is used to treat ...

Limonene Limonene is a colorless liquid aliphatic hydrocarbon classified as a cyclic monoterpene, and is the major component in the oil of citrus fruit peels. The -isomer, occurring more commonly in nature as the fragrance of oranges, is a flavoring ...

Linalool Linalool () refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Linalool has multiple commercial applications, the majority of which are based on its pleasant scent (floral, with a touch o ...

Menthol Menthol is an organic compound, more specifically a monoterpenoid, made synthetically or obtained from the oils of corn mint, peppermint, or other mints. It is a waxy, clear or white crystalline substance, which is solid at room temperature and ...

Myristicin Myristicin is a naturally occurring compound found in common herbs and spices, the most well known being nutmeg. It is an insecticide, and has been shown to enhance the effectiveness of other insecticides in combination. Myristicin is also a pre ...

Neem ''Azadirachta indica'', commonly known as neem, nimtree or Indian lilac, is a tree in the mahogany family Meliaceae. It is one of two species in the genus '' Azadirachta'', and is native to the Indian subcontinent and most of the countries in Afr ...

( Azadirachtin) * Nicotine *

Nootkatone Nootkatone is a natural organic compound, a sesquiterpenoid, and a ketone that is the most important and expensive aromatic of grapefruit, and which also occurs in other organisms. Previously, nootkatone was thought to be one of the main chemical ...

* ''

Peganum harmala ''Peganum harmala'', commonly called wild rue, Syrian rue, African rue, esfand or espand,Mahmoud OmidsalaEsfand: a common weed found in Persia, Central Asia, and the adjacent areasEncyclopedia Iranica Vol. VIII, Fasc. 6, pp. 583–584. Originall ...

'', seeds (smoke from), root *

Oregano Oregano (, ; ''Origanum vulgare'') is a species of flowering plant in the mint family Lamiaceae. It was native to the Mediterranean region, but widely naturalised elsewhere in the temperate Northern Hemisphere. Oregano is a woody perennial pla ...

oil kills '' Rhyzopertha dominica'' (bug found in stored cereal) *

* ''

Quassia ''Quassia'' ( or ) is a plant genus in the family Simaroubaceae. Its size is disputed; some botanists treat it as consisting of only one species, '' Quassia amara'' from tropical South America, while others treat it in a wide circumscription as ...

'' (South American plant genus) * Ryanodine * Spinosad AKA Spinosyn A *

Spinosyn D Spinosad is an insecticide based on chemical compounds found in the bacterial species '' Saccharopolyspora spinosa''. The genus ''Saccharopolyspora'' was discovered in 1985 in isolates from crushed sugarcane. The bacteria produce yellowish-pink ae ...

* Tetranortriterpenoid *

Thymol Thymol (also known as 2-isopropyl-5-methylphenol, IPMP), , is a natural monoterpenoid phenol derivative of ''p''-Cymene, isomeric with carvacrol, found in oil of thyme, and extracted from '' Thymus vulgaris'' (common thyme), ajwain, and va ...

(controls varroa mites in bee colonies)

Biologicals

* Bacillus sphaericus *

Bacillus thuringiensis aizawi
*

Bacillus thuringiensis israelensis ''Bacillus thuringiensis'' serotype ''israelensis'' (Bti) is a group of bacteria used as biological control agents for larvae stages of certain dipterans. Bti produces toxins which are effective in killing various species of mosquitoes, fungus ...

* Bacillus thuringiensis kurstakihttp://www.biocontrol.entomology.cornell.edu/pathogens/bacteria.html * Bacillus thuringiensis tenebrionis * Nuclear Polyhedrosis virus * Granulovirus * Lecanicillium lecanii

Inorganic/mineral derived insecticides

Diatomaceous earth Diatomaceous earth (), diatomite (), or kieselgur/kieselguhr is a naturally occurring, soft, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging from more than 3 μm to ...

Borax Borax is a salt (chemistry), salt (ionic compound), a hydration (chemistry), hydrated borate of sodium, with chemical formula often written . It is a colorless crystalline solid, that dissolves in water to make a base (chemistry), basic aqueo ...

Boric Acid Boric acid, more specifically orthoboric acid, is a compound of boron, oxygen, and hydrogen with formula . It may also be called hydrogen borate or boracic acid. It is usually encountered as colorless crystals or a white powder, that dissolve ...

References

External links

InsectBuzz.com
- Daily updated news on insects and their relatives, including information on insecticides and their alternatives
International Pesticide Application Research Centre (IPARC)

Pestworld.org
– Official site of the National Pest Management Association * Streaming online video about efforts to reduce insecticide use in rice in Bangladesh
on Windows Media Playeron RealPlayer

– Has a thorough explanation on how insecticides work.

Michigan State University Extension * Example of Insecticide application in th

(Japanese dry rock garden) in Lelystad, The Netherlands. * {{Authority control Biocides

Type of activity

Systemic insecticides

Contact insecticides

Synthetic insecticides

Development

Organochlorides

Organophosphates

Carbamates

Pyrethroids

Neonicotinoids

Phenylpyrazoles

Butenolides

Ryanoids/diamides

Insect growth regulators

Biological pesticides

Other biological approaches

Plant-incorporated protectants

= ''Bacillus thuringiensis''

= RNA interference

= Venom

Enzymes

Bacterial

Other

Synthetic insecticide and natural insecticides

Environmental harm

Effects on nontarget species

DDT

Runoff and Percolation

Pollinator decline

Bird decline

Alternatives

Examples

Organochloride An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one covalently bonded atom of chlorine. The chloroalkane class (alkanes with one or more hydrogens substituted by chlor ...s

Organophosphate In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered ...s

Carbamate In organic chemistry, a carbamate is a category of organic compounds with the general formula and structure , which are formally derived from carbamic acid (). The term includes organic compounds (e.g., the ester ethyl carbamate), formall ...s

Pyrethroid A pyrethroid is an organic compound similar to the natural pyrethrins, which are produced by the flowers of pyrethrums (''Chrysanthemum cinerariaefolium'' and '' C. coccineum''). Pyrethroids are used as commercial and household insecticides. In ...s

Neonicotinoid 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 ...s

Ryanoids

Insect growth regulators

Derived from plants or microbes

Biologicals

Inorganic/mineral derived insecticides

See also

References

Further reading

External links

Organochloride An organochloride, organochlorine compound, chlorocarbon, or chlorinated hydrocarbon is an organic compound containing at least one covalently bonded atom of chlorine. The chloroalkane class (alkanes with one or more hydrogens substituted by chlor ...
s

Organophosphate In organic chemistry, organophosphates (also known as phosphate esters, or OPEs) are a class of organophosphorus compounds with the general structure , a central phosphate molecule with alkyl or aromatic substituents. They can be considered ...
s

Carbamate In organic chemistry, a carbamate is a category of organic compounds with the general formula and structure , which are formally derived from carbamic acid (). The term includes organic compounds (e.g., the ester ethyl carbamate), formall ...
s

Pyrethroid A pyrethroid is an organic compound similar to the natural pyrethrins, which are produced by the flowers of pyrethrums (''Chrysanthemum cinerariaefolium'' and '' C. coccineum''). Pyrethroids are used as commercial and household insecticides. In ...
s

Neonicotinoid 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 ...
s