A pesticide is any chemical which is used by man to control pests. The pests may be insects, plant diseases, fungi, weeds, nematodes, snails, slugs, etc. Therefore, insecticides, fungicides, herbicides, etc., are all types of pesticides. Some pesticides must only contact (touch) the pest to be deadly. Others must be swallowed to be effective. The way that each pesticide attacks a pest suggests the best way to apply it; to reach and expose all the pests. For example, a pesticide may be more effective and less costly as a bait, rather than as a surface spray.
Types of Pesticides
A bactericide or bacteriocide is a substance that kills bacteria and, preferably, nothing else. Bactericides are either disinfectants, antiseptics or antibiotics.
Fungicides are chemical compounds used to prevent the spread of fungi or plants in gardens and crops, which can cause serious damage resulting in loss of yield and thus profit. Though oomycetes are not fungi, they use the same mechanisms to infect plants and therefore in phytopathology chemicals used to control oomycetes are also referred to as fungicides. Fungicides are also used to fight fungal infections.Fungicides can either be contact or systemic. A contact fungicide kills fungi when sprayed on its surface; a systemic fungicide has to be absorbed by the plant.Fungicide residues have been found on food for human consumption, mostly from post-harvest treatments. Some fungicides are dangerous to human health, such as Vinclozolin, which has now been removed from use.Like other pesticides, fungicides can induce pesticide resistance. Equivalently, antifungal drugs can induce drug resistance.
A herbicide is used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often based on plant hormones. Herbicides used to clear waste ground are nonselective and kill all plant material with which they come into contact. Some plants produce natural herbicides, such as the genus Juglans (walnuts). Herbicides are widely used in agriculture and in landscape turf management. They are applied in total vegetation control (TVC) programs for maintenance of highways and railroads. Smaller quantities are used in forestry, pasture systems, and management of areas set aside as wildlife habitat.
An insecticide is a pesticide used against insects in all developmental forms. They include ovicides and larvicides used against the eggs and larvae of insects. Insecticides are used in agriculture, medicine, industry and the household. 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.
Miticides or acaricides are pesticides that kill mites. Antibiotic miticides, carbamate miticides, formamidine miticides, mite growth regulators, organochlorine, permethrin and organophosphate miticides are all in this category. Diatomaceous earth will also kill mites by cutting through the skin which drys out the mite. Ivermectin can be prescribed by a medical doctors to rid humans of mite and lice infestations and there are agricultural formulations for birds and rodents that are infested.
Methoprene is virtually harmless to non-insects, and the US EPA has exempted it from tolerance. It is widely available in supermarkets, ctc. Hydroprene is toxic to fish & perhaps birds. Both are for indoor use only, as they break down in sunlight. Methoprene is applied as a wetting spray, hydroprene as an aerosol space spray. Neither will affect adult insects; they work on future generations by preventing growth or maturation. Permethrin can be applied as a spray or in more targeted forms (e.g. Damminix TickTubes ) that attack the ticks and mites on mammalian hosts. Their effects are not limited to mites: lice, cockroaches, fleas, mosquitos, & other insects will be affected. Permethrin, however, is not known to harm mammals or birds, as it has a low mammalian toxicity and is poorly absorbed by skin.
Molluscicides are pesticides used to control molluscs, such as motts, slugs and snails. These substances include metaldehyde, methiocarb and aluminium sulfate. They should be used with caution, as they can be harmful to non-target animals. Most molluscicides are not used in organic gardening, though there are exceptions, such as iron phosphate.
A nematicide is a type of chemical pesticide used to kill parasitic nematodes (roundworms). One common nematicide is obtained from neem cake, the residue obtained after cold-pressing the fruit and kernels of the neem tree. Known by several names in the world, the tree was first cultivated in India since ancient times and is now widely distributed throughout the world.
Rodenticides are a category of pest control chemicals intended to kill rodents.Single feed baits are chemicals sufficiently dangerous that the first dose is sufficient to kill.Rodents are difficult to kill with poisons because their feeding habits reflect their place as scavengers. They will eat a small bit of something and wait, and if they don't get sick, they continue. An effective rodenticide must be tasteless and odorless in lethal concentrations, and have a delayed effect.
It is for the control of viruses.
Pesticides can also be classed as synthetic pesticides or biological pesticides, although the distinction can sometimes blur.
Broad-Spectrum Pesticides are those that kill an array of species, while narrow-spectrum, or selective pesticides only kill a small group of species
A Systemic Pesticide moves inside a plant following absorption by the plant. This movement is usually upward (through the xylem) and outward. Increased efficiency may be a result. Systemic insecticides which poison pollen and nectar in the flowers may kill needed pollinators such as bees.
Uses and Benefits
Pesticides are used to control organisms which can otherwise result in harm.For example, they are used to kill mosquitoes that can transmit potentially deadly diseases like west nile virus and malaria and bees, wasps or ants that can cause allergic reactions. Insecticides can protect animals, because infestations by parasites such as fleas may cause them illness.Pesticides can prevent sickness in humans that could be caused by moldy food or diseased produce. Herbicides can prevent accidents by clearing roadside trees and brush, which may block visibility. They can also kill invasive weeds in parks and wilderness areas which may cause environmental damage. Uncontrolled pests such as termites and mold can damage structures such as houses.Pesticides are often very cost-effective for farmers. Pesticides are used in grocery stores and food storage facilities to manage rodents and insects that infest food such as grain. Each use of a pesticide carries some associated risk. Proper pesticide use decreases these associated risks to a level deemed acceptable and increases quality of life and protects property and the environment.
In 2006, the World Health Organization suggested the resumption of the limited use of DDT to fight malaria. They called for the use of DDT to coat the inside walls of houses in areas where mosquitoes are prevalent. Dr. Arata Kochi, WHO's malaria chief, said, "One of the best tools we have against malaria is indoor residual house spraying. Of the dozen insecticides WHO has approved as safe for house spraying, the most effective is DDT."Scientists estimate that DDT and other chemicals in the organophosphate class of pesticides have saved 7 million human lives since 1945 by preventing the transmission of diseases such as malaria, bubonic plague, sleeping sickness, and typhus.
Pesticides Banned for manufacture, import and use (25 Nos.)
Pesticide / Pesticide formulations banned for use but their manufacture is allowed for export (2 Nos.)
Captafol 80% Powder
Pesticide formulations banned for import, manufacture and use (4 Nos)
Methomyl 24% L
Methomyl 12.5% L
Phosphamidon 85% SL
Carbofuron 50% SP
Pesticide Withdrawn(7 Nos)
Pesticides Restricted for use in India
Effect of Pesticides on human health
The effect of pesticides on human health is worst.Due to pesticides there can be number of diseases which are lungs cancer Chronic liver damage cirrhosis and chronic hepatitis, endocrine and reproductive disorders, immuno suppression, cytogenic effects, breast cancer, Non hodkins lymphoma, polyneuritis, etc, etc