An insecticide is a pesticide used against insects in all developmental forms. A pesticide is a substance or mixture of substances used to kill a pest. Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described They include ovicides and larvicides used against the eggs and larvae of insects respectively. A larvicide (alternatively larvacide) is an Insecticide that is specifically targeted against the Larval life stage of an Insect. In most Birds and Reptiles an egg ( Latin ovum) is the Zygote, resulting from Fertilization of the Ovum. A larva ( Latin; plural larvae) is a juvenile form of Animal with indirect development, undergoing Metamorphosis (for example Insecticides are used in agriculture, medicine, industry and the household. Agriculture refers to the production of goods through the growing of plants and fungi and the raising of domesticated Animals The study of agriculture Medicine is the art and science of healing It encompasses a range of Health care practices evolved to maintain and restore Human Health by the For other uses of this term see Industry (disambiguation An industry (from Latin industrius, "diligent industrious" The household is the basic unit of analysis in many Social, Microeconomic and Government models The use of insecticides is believed to be one of the major factors behind the increase in agricultural productivity in the 20th century. Nearly all insecticides have the potential to significantly alter ecosystems; many are toxic to humans; and others are concentrated in the food chain. It is necessary to balance agricultural needs with environmental and health issues when using insecticides.
The classification of insecticides is done in several different ways:
Heavy metals, e. g. lead, mercury, arsenic, as well as plant toxins such as nicotine have been used for many years. Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum Arsenic (ˈɑrsənɪk is a Chemical element that has the symbol As and Atomic number of 33 Nicotine is an Alkaloid found in the Nightshade family of plants ( Solanaceae) which constitutes approximately 0 Various plants have been used as folk insecticides for centuries, including tobacco and pyrethrum. Tobacco is an Agricultural product recognized as an addictive drug processed from the fresh Leaves of plants in the genus Nicotiana. Pyrethrum refers to several Old World plants of the genus Chrysanthemum (e Some farmers are reporting successfully using spray of crudely fermented alcohol as an effective insecticide.
With the rise of the modern chemical industry it was possible to form organochlorides, such as chlorinated hydrocarbons. Applications The simplest form of organochlorides are chlorinated Hydrocarbons These consist of simple Hydrocarbons in which one or more hydrogen atoms have Applications The simplest form of organochlorides are chlorinated Hydrocarbons These consist of simple Hydrocarbons in which one or more hydrogen atoms have The organochlorides used in chemical warfare tend to be more potent electrophiles than those used as insecticides. In Chemistry, an electrophile (literally electron-lover) is a Reagent attracted to Electrons that participates in a chemical reaction by accepting For instance mustard gas (sulfur mustard, HD) is a potent alklating agent which uses neighbouring group participation of the sulfur to make the alkyl chloride a stronger electrophile. The sulfur mustards, of which mustard gas ( Bis (2-chloroethyl sulfide is a member are a class of related Cytotoxic, Vesicant Chemical The sulfur mustards, of which mustard gas ( Bis (2-chloroethyl sulfide is a member are a class of related Cytotoxic, Vesicant Chemical Neighbouring group participation or NGP in Organic chemistry has been defined by IUPAC as the interaction of a reaction centre with a Lone pair The haloalkanes (also known as halogenoalkanes or alkyl halides) are a group of Chemical compounds consisting of Alkanes such as Methane It is likely that the chlorine in DDT is used to tune the lipophilicity of the compound, and to alter the shape and electrostatic effects involved in the interactions of the insecticide and the biomolecules in the target organism. Lipophilicity, fat-liking, refers to the ability of a Chemical compound to dissolve in fats oils lipids and non-polar solvents such as Hexane or For instance DDT works by opening the sodium channels in the nerve cells of the insect. Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22
The next large class was the organophosphates, both the insecticides and the chemical warfare agents (such as sarin, tabun, soman and VX) work in the same way. An organophosphate (sometimes abbreviated OP) is the general name for Esters of Phosphoric acid. Sarin, also known by its NATO designation of GB, is an extremely toxic substance whose sole application is as a Nerve agent. Effects of overexposure The exact symptoms of overexposure are similar to those created by all Nerve agents Tabun like all nerve agents is toxic even in minute doses Alternative names Soman is occasionally referred to by names other than soman or GD: Phosphonofluoridic acid methyl- 1 2 2-trimethylpropyl ester VX (S--O-ethyl methylphosphonothioate is an extremely toxic substance whose sole application is as a Nerve agent. All these compounds bind to acetylcholinesterase and other cholinesterases. This results in disruption of nervous impulses, killing the insect or interfering with its ability to carry on normal functions. Carbamate insecticides have similar toxic mechanisms but have a much shorter duration of action and are thus somewhat less toxic. Carbamates, or Urethanes are a group of Organic compounds sharing a common Functional group with the general structure -NH(COO-
Organophosphates have an additive toxic effect to wildlife, so multiple exposures to the chemicals amplifies the toxicity. 
To mimic the insecticidal activity of the natural compound pyrethrum another class of pesticides, pyrethroid pesticides, have been developed. Pyrethrum refers to several Old World plants of the genus Chrysanthemum (e A pyrethroid is a synthetic Chemical compound similar to the natural chemical Pyrethrins produced by the flowers of Pyrethrums ( Chrysanthemum cinerariaefolium These are nonpersistent and much less acutely toxic than organophosphates and carbamates.
Synthetic analogues of the natural insecticide nicotine (with a much lower acute mammalian toxicity and greater field persistence). Nicotine is an Alkaloid found in the Nightshade family of plants ( Solanaceae) which constitutes approximately 0 Broad-spectrum – systemic insecticides with a rapid action (minutes-hours). They are applied as sprays, drenches, seed and soil treatments - often as substitutes for organophosphates and carbamates. Treated insects exibit leg tremors, rapid wing motion, stylet withdrawal (aphids), disorientated movement, paralysis and death.
Recent efforts to reduce broad spectrum toxins added to the environment have brought biological insecticides back into vogue. Recent efforts to reduce the impact of broad-spectrum chemical Pesticides have brought biological insecticides back into vogue An example is the development and increase in use of Bacillus thuringiensis, a bacterial disease of Lepidopterans and some other insects. Bacillus thuringiensis is a Gram-positive, soil dwelling Bacterium of the Genus Bacillus. Lepidoptera is an order of Insect that includes Moths and butterflies. It is used as a larvicide against a wide variety of caterpillars. A larvicide (alternatively larvacide) is an Insecticide that is specifically targeted against the Larval life stage of an Insect. Caterpillars are the Larval form of a member of the order Lepidoptera (the Insect order comprising butterflies and Moths Because it has little effect on other organisms, it is considered more environmentally friendly than synthetic pesticides. Environmental friendly, eco-friendly, and nature friendly are synonyms used to refer to Goods and services considered to inflict minimal harm The toxin from Bacillus thuringiensis (Bt toxin) has been incorporated directly into plants through the use of genetic engineering. Bacillus thuringiensis is a Gram-positive, soil dwelling Bacterium of the Genus Bacillus. Genetic engineering, Recombinant DNA technology, genetic modification/manipulation (GM and gene splicing are terms that apply to the direct Other biological insecticides include products based on entomopathogenic fungi (e. g. Metarhizium anisopliae), nematodes (e. Metarhizium anisopliae, formerly known as Entomophthora anisopliae ( Basionym) is a Fungus that grows naturally in soils throughout the g. Steinernema feltiae) and viruses (e. g. Cydia pomonella granulovirus).
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 insecticide granules on the ground for food and eat it. 
Sprayed insecticides may drift from the area to which it is applied and into wildlife areas, especially when it is sprayed aerially. 
One of the bigger drivers in the development of new insecticides has been the desire to replace toxic and irksome insecticides. DDT (from its trivial name D ichloro- D iphenyl- T richloroethane is one of the best known synthetic Pesticides It is a chemical with a long Toxicity is the degree to which a substance is able to damage an exposed organism DDT was introduced as a safer alternative to the lead and arsenic compounds. DDT (from its trivial name D ichloro- D iphenyl- T richloroethane is one of the best known synthetic Pesticides It is a chemical with a long Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly Arsenic (ˈɑrsənɪk is a Chemical element that has the symbol As and Atomic number of 33 It is the case that when used under the correct conditions that almost any chemical substance is 'safe', but when used under the wrong conditions most insecticides can be a threat to health and/or the environment. See also Nature The natural environment, commonly referred to simply as the environment, is a terminology that is comprised of all living and
Some insecticides have been banned due to the fact that they are persistent toxins which have adverse effects on animals and/or humans. An oft-quoted case is that of DDT, an example of a widely used (and maybe misused) pesticide, which was brought to public attention by Rachel Carson's book, Silent Spring. DDT (from its trivial name D ichloro- D iphenyl- T richloroethane is one of the best known synthetic Pesticides It is a chemical with a long Rachel Louise Carson (May 27 1907 – April 14 1964 was an American marine biologist and Nature writer whose writings are credited with advancing the global One of the better known impacts of DDT is to reduce the thickness of the egg shells on predatory birds. The shells sometimes become too thin to be viable, causing reductions in bird populations. This occurs with DDT and a number of related compounds due to the process of bioaccumulation, wherein the chemical, due to its stability and fat solubility, accumulates in organisms' fatty tissues. Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at ftudruinsubstance is lost Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water Also, DDT may biomagnify which causes progressively higher concentrations in the body fat of animals farther up the food chain. Biomagnification, also known as bioamplification, or biological magnification is the increase in concentration of a substance such as the Pesticide Food chains, also called food networks and/or trophic networks, describe the feeding relationships between species within an Ecosystem. The near-worldwide ban on agricultural use of DDT and related chemicals has allowed some of these birds--such as the peregrine falcon--to recover in recent years. The Peregrine Falcon ( Falco peregrinus) also known simply as the Peregrine, and historically as the "Duck Hawk" in North America is a A number of the organochlorine pesticides have been banned from most uses worldwide and globally they are controlled via the Stockholm Convention on persistent organic pollutants. Applications The simplest form of organochlorides are chlorinated Hydrocarbons These consist of simple Hydrocarbons in which one or more hydrogen atoms have Stockholm Convention is an international legally binding agreement on persistent organic pollutants (POPs Persistent organic pollutants ( POP s are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic These include: aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, mirex and toxaphene. Aldrin is an organochlorine Insecticide which is oxidized in the Insect to form Dieldrin, a Neurotoxin. Chlordane is a manufactured chemical that was used as a Pesticide in the United States from 1948 to 1988 DDT (from its trivial name D ichloro- D iphenyl- T richloroethane is one of the best known synthetic Pesticides It is a chemical with a long Dieldrin is a Chlorinated hydrocarbon originally produced in 1948 by J Endrin is a cyclodiene Insecticide used on Cotton, Maize, and Rice. Heptachlor is an Insecticide that usually comes in the form of a white or tan powder the tan powder being of lower purity Mirex has been listed as persistent bioaccumulative and toxic pollutants target by EPA Toxaphene is an Organic compound with the approximate Empirical formula C10H10Cl8 and average Molecular mass of 414
Insecticides can kill bees and may be a cause of pollinator decline, the loss of species that pollinate plants, including through the mechanism of Colony Collapse Disorder, in which worker bees from a beehive or Western honey bee colony abruptly disappear. Pesticides vary in their effect on Bees. Contact Insecticides those which kill by touching the organism affect the Worker bee that The term Pollinator decline refers to the reduction in abundance of Pollinators in many Ecosystems worldwide during the end of the twentieth century Pollination in angiosperms and Gymnosperms is the process that transfers pollen grains, which contain the male Gametes (sperm to where the female Colony Collapse Disorder (or CCD) is a phenomenon in which worker bees from a beehive or Western honey bee colony abruptly disappear A beehive is in a general sense an enclosed structure in which some species of Honey bees (genus Apis) live and raise their young Loss of pollinators will mean a reduction in crop yields. 
Integrated pest management or IPM in the home begins with restricting the availability to insects of three vital commodities: shelter, water and food. In Agriculture, Integrated Pest Management (IPM is a pest control strategy that uses an array of complementary methods mechanical devices physical devices If insects become a problem despite such measures, IPM seeks to control them using the safest possible methods, targeting the approach to the particular pest.
Insect repellent, referred to as "bug spray", comes in a plastic bottle or aerosol can. An insect repellent is a substance applied to skin clothing or other surfaces which discourages Insects (and Arthropods in general from landing or climbing on that Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products Aerosol spray is a type of dispensing system which creates an aerosol mist of liquid particles Applied to clothing, arms, legs, and other extremities, the use of these products will tend to ward off nearby insects. This is not an insecticide.
Insecticide used for killing pests—most often insects, and arachnids—primarily comes in an aerosol can, and is sprayed into the air or a nest as a means of killing the animal. A pest is an organism which has characteristics that are regarded by Humans as injurious or unwanted Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described Arachnids are a class ( Arachnida) of joint-legged Invertebrate Animals in the subphylum Chelicerata. Fly sprays will kill house flies, blowflies, ants, cockroaches and other insects and also spiders. The housefly (also house fly, house-fly or common housefly) Musca domestica, is the most common of all Flies Ants are social Insects of the family Formicidae and along with the related families of Wasps and Bees belong to the order Cockroaches (or simply "roaches" are Insects of the order Blattaria. Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described Spiders are Predatory Invertebrate Animals that have two body segments, eight legs no chewing mouth parts and no wings Other preparations are granules or liquids that are formulated with bait that is eaten by insects. For many household pests bait traps are available that contain the pesticide and either pheromone or food baits. Crack and crevice sprays are applied into and around openings in houses such as baseboards and plumbing. Pesticides to control termites are often injected into and around the foundations of homes. The termites are a group of Social Insects usually classified at the taxonomic rank of order Isoptera (but see also taxonomy
Active ingredients of many household insecticides include permethrin and tetramethrin, which act on the nervous system of insects and arachnids. Permethrin is a common synthetic chemical widely used as an Insecticide and Acaricide and as an Insect repellent. Tetramethrin is a potent synthetic Insecticide in the Pyrethroid family
Bug sprays should be used in well ventilated areas only, as the chemicals contained in the aerosol and most insecticides can be harmful or deadly to humans and companion animals. All insecticide products including solids, baits and bait traps should be applied such that they are out of reach of wildlife, companion animals and children.