PESTICIDE

What is a pesticide?

A pesticide is any substance or mixture of substances intended for:

·   preventing

·   destroying

·   repelling

·   mitigating any pest.

Though often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides, fungicides, and various other substances used to control pests.

Under United States law, a pesticide is also any substance or mixture of substances intended for use as a plant regulator, defoliant, or desiccant.

What is a pest?

Pests are living organisms that occur where they are not wanted or that cause damage to crops or humans or other animals. Examples include:

·   insects

·   mice and other animals

·   unwanted plants (weeds)

·   fungi

·   microorganisms such as bacteria and viruses

·   prions

Do household products contain pesticides?

Many household products are pesticides. All of these common products are considered pesticides:

·   Cockroach sprays and baits

·   Insect repellents for personal use.

·   Rat and other rodent poisons.

·   Flea and tick sprays, powders, and pet collars.

·   Kitchen, laundry, and bath disinfectants and sanitizers.

·   Products that kill mold and mildew.

·   Some lawn and garden products, such as weed killers.

·   Some swimming pool chemicals.

What is the balance between the risks and benefits of pesticides?

By their very nature, most pesticides create some risk of harm - Pesticides can cause harm to humans, animals, or the environment because they are designed to kill or otherwise adversely affect living organisms.

At the same time, pesticides are useful to society - Pesticides can kill potential disease-causing organisms and control insects, weeds, and other pests.

Are some pesticides safer than others?

Biologically-based pesticides, such as pheromones and microbial pesticides, are becoming increasingly popular and often are safer than traditional chemical pesticides.

What about pest control devices?

A pest control "device" is any instrument or contrivance (other than a firearm) intended for trapping, destroying, repelling, or mitigating any pest. A black light trap is an example of a device.

What substances are not regulated as pesticides?

The U.S. definition of pesticides is quite broad, but it does have some exclusions:

·   Drugs used to control diseases of humans or animals (such as livestock and pets) are not considered pesticides; such drugs are regulated by the Food and Drug Administration.

·   Fertilizers, nutrients, and other substances used to promote plant survival and health are not considered plant growth regulators and thus are not pesticides.

·   Biological control agents, except for certain microorganisms. (Biological control agents include beneficial predators such as birds or ladybugs that eat insect pests.)

Types of Pesticides

Pesticides are often referred to according to the type of pest they control. Another way to think about pesticides is to consider those that are chemical pesticides or are derived from a common source or production method. Other categories include biopesticides, antimicrobials, and pest control devices.

Chemical Pesticides

Some examples of chemically-related pesticides follow. Other examples are available in sources such as Recognition and Management of Pesticide Poisonings.

Organophosphate Pesticides - These pesticides affect the nervous system by disrupting the enzyme that regulates acetylcholine, a neurotransmitter. Most organophosphates are insecticides. They were developed during the early 19th century, but their effects on insects, which are similar to their effects on humans, were discovered in 1932. Some are very poisonous (they were used in World War II as nerve agents). However, they usually are not persistent in the environment.

Carbamate Pesticides affect the nervous system by disupting an enzyme that regulates acetylcholine, a neurotransmitter. The enzyme effects are usually reversible. There are several subgroups within the carbamates.

Organochlorine Insecticides were commonly used in the past, but many have been removed from the market due to their health and environmental effects and their persistence (e.g. DDT and chlordane).

Pyrethroid Pesticides were developed as a synthetic version of the naturally occurring pesticide pyrethrin, which is found in chrysanthemums. They have been modified to increase their stability in the environment. Some synthetic pyrethroids are toxic to the nervous system.

Biopesticides

Biopesticides are certain types of pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals. For example, canola oil and baking soda have pesticidal applications and are considered biopesticides. At the end of 2001, there were approximately 195 registered biopesticide active ingredients and 780 products. Biopesticides fall into three major classes:

(1) Microbial pesticides consist of a microorganism (e.g., a bacterium, fungus, virus or protozoan) as the active ingredient. Microbial pesticides can control many different kinds of pests, although each separate active ingredient is relatively specific for its target pest[s]. For example, there are fungi that control certain weeds, and other fungi that kill specific insects.

The most widely used microbial pesticides are subspecies and strains of Bacillus thuringiensis, or Bt. Each strain of this bacterium produces a different mix of proteins, and specifically kills one or a few related species of insect larvae. While some Bt's control moth larvae found on plants, other Bt's are specific for larvae of flies and mosquitoes. The target insect species are determined by whether the particular Bt produces a protein that can bind to a larval gut receptor, thereby causing the insect larvae to starve

(2) Plant-Incorporated-Protectants (PIPs) are pesticidal substances that plants produce from genetic material that has been added to the plant. For example, scientists can take the gene for the Bt pesticidal protein, and introduce the gene into the plant's own genetic material. Then the plant, instead of the Bt bacterium, manufactures the substance that destroys the pest.

(3) Biochemical pesticides are naturally occurring substances that control pests by non-toxic mechanisms. Conventional pesticides, by contrast, are generally synthetic materials that directly kill or inactivate the pest. Biochemical pesticides include substances, such as insect sex pheromones, that interfere with mating, as well as various scented plant extracts that attract insect pests to traps. Because it is sometimes difficult to determine whether a substance meets the criteria for classification as a biochemical pesticide.

Pest Types

Pesticides that are related because they address the same type of pests include:

Algicides

Control algae in lakes, canals, swimming pools, water tanks, and other sites.

Antifouling agents

Kill or repel organisms that attach to underwater surfaces, such as boat bottoms.

AntimicrobialsAntimicrobials

Kill microorganisms (such as bacteria and viruses).

Attractants

Attract pests (for example, to lure an insect or rodent to a trap). (However, food is not considered a pesticide when used as an attractant.)

Biopesticides

Biopesticides are certain types of pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals.

Biocides

Kill microorganisms.

Disinfectants and sanitizers

Kill or inactivate disease-producing microorganisms on inanimate objects.

Fungicides

Kill fungi (including blights, mildews, molds, and rusts).

Fumigants

Produce gas or vapor intended to destroy pests in buildings or soil.

Herbicides

Kill weeds and other plants that grow where they are not wanted.

Insecticides

Kill insects and other arthropods.

Miticides (also called acaricides)

Kill mites that feed on plants and animals.

Microbial pesticides

Microorganisms that kill, inhibit, or out compete pests, including insects or other microorganisms.

Molluscicides

Kill snails and slugs.

Nematicides

Kill nematodes (microscopic, worm-like organisms that feed on plant roots).

Ovicides

Kill eggs of insects and mites.

Pheromones

Biochemicals used to disrupt the mating behavior of insects.

Repellents

Repel pests, including insects (such as mosquitoes) and birds.

Rodenticides

Control mice and other rodents.

The term pesticide also includes these substances:

Defoliants

Cause leaves or other foliage to drop from a plant, usually to facilitate harvest.

Desiccants

Promote drying of living tissues, such as unwanted plant tops.

Insect growth regulators

Disrupt the molting, maturity from pupal stage to adult, or other life processes of insects.

Plant growth regulators

Substances (excluding fertilizers or other plant nutrients) that alter the expected growth, flowering, or reproduction rate of plants.

 Source: http://www.epa.gov