Kill Insects

Most spiccics of insects arc beneficial or even essential to agriculture. 1 loneybees, for example, arc responsible for the pollination of 10 billion worth of produce in the United States. Countless other species take part in nutrient recycling and help maintain soil quality. A small minority of insect. species, however, has continually threatened our capacity to grow, harvest, and store crops, and it is against these species that insecticides are u.sed. The most widely used insecticides are chlorinated hydrocarbons, organophosphorus compounds, and carbamates. 

The chlorinatedhydrocarbonsYimc a remarkable persistence, killing insects for months and years on treated surfaces, fhere arc at least two reasons for this persistence. First, chlorinated hydrocarbons tend to be nonbiodcgradable, which means there are no natural pathways to break them down chemically. Second, they arc nonpolar compounds, which means they are insoluble in water and so are not wa.shed away by rainwater. 

scct populations be an to develop a resistance to DD F within a few years of its first application. Furthermore, DDT was found to be toxic to wildlife, including the natural predators of in.sects, such as birds. With fewer natural predators, DDT-rcsistant insects were able to thrive. The early increased crop yields resulting from DDT use were therefore not sustainable. 

Rachel Caison was a pioneer in the fight gainst excessive u.sc of pesticides. 

The DDT concenrrarion in a food chain can be magnified from 0.000003 parts per million (ppm) as a pollutant in the water to 25 ppm in a bird at the top of the chain. 

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Fumigation The result of a pollutant being trapped under or in an inversion layer, or the process of using poisonous gases to kill insects. 

Another potential application of radioactive species is in food preservation (Figure 19.2, p. 518). It is well known that gamma rays can kill insects, larvae, and parasites such as... 

Methyl parathion is a pesticide that is used to kill insects on crops. Usually, it is sprayed on the crops. Methyl parathion comes in two forms a pure form of white crystals and a technical-grade solution (brownish liquid), which contains methyl parathion (80%) and inactive ingredients in a solvent. The technical-grade methyl parathion smells like rotten eggs or garlic. Methyl parathion is a manufactured chemical, so it is found in the environment only as a result of its manufacture or use. Methyl parathion has been manufactured in the United States since 1952 and has been used to kill insects on many types of crops since this time. Because methyl... 

Methyl parathion can enter your body if you eat food or drink water containing it if you swim, bathe, or shower in contaminated water if you touch recently sprayed plants or soil if you touch contaminated soil near hazardous waste sites or if you breathe air that contains methyl parathion, such as near factories or recently sprayed farm fields (or in recent accounts of the illegal use of methyl parathion, if you breathe air or touch contaminated surfaces inside homes where methyl parathion has been used to kill insects). By any means of exposure, methyl parathion goes into your body quickly and gets into your blood. From your bloodstream, methyl parathion goes to your liver, brain, and other organs. Your liver changes some of methyl parathion to a more harmful chemical called methyl paraoxon. Both methyl parathion and methyl paraoxon can bind to enzymes of your nerves within minutes or hours. Your liver breaks down methyl parathion and methyl paraoxon into less harmful substances. These less harmful substances leave your body in urine within hours or days. For more information, see Chapter 3. 

Families should also be aware that sometimes methyl parathion has been illegally sprayed inside the home to kill insects. Your children may be exposed to methyl parathion if an unqualified person applies pesticides containing it around your home. In some cases, the improper use of pesticides banned for use in homes has turned homes into hazardous waste sites. Make sure that any person you hire is licensed and, if appropriate, certified to apply pesticides. Your state licenses each person who is qualified to apply pesticides according to EPA standards and further certifies each person who is qualified to apply restricted use pesticides. Ask to see the license... 

Methyl parathion has been illegally used inside the home to kill insects (ATSDR 1999 EPA 1999b). 

Methyl parathion is only for use on agricultural crops. The reports that methyl parathion has been illegally/improperly used inside homes to kill insects (ATSDR 1999 EPA 1999b) show that people in homes that are sprayed with methyl parathion may be exposed to dangerously high levels of methyl parathion. 

Standard control practices developed within these limitations have taken all the various factors into consideration. Entomologists recognize the inadequacy of many of the recommended control measures. They have initiated the effort to develop new and more effective insecticides and welcomed the interest and assistance of others. The recent accelerated development of new insecticides has opened new fields and done much to stimulate public interest in insect control. Much more needs to be learned than to know that the new materials will kill insects, before their true worth can be determined. We must determine many things. Knowledge of the effect on beneficial insects, wild life, soil, and machines is important. Of greater importance is Are they safe for the operator and for those who handle and use the product ... 

The absorption of the ether bis(2-fluoroethoxy)methane from the soil and its translocation in plants in a concentration sufficient to kill insects is a recent discovery heretofore observed only in some selenium compounds and in the insecticidal esters of some polyphosphoric acids (4) Whether this property is shared by other organofluorine compounds will doubtless be determined for the purpose of studying plant metabolism and of evaluating any practical application. 

Sometime after the British reached Hamburg, they found the files of "Tesch and Stabenow." For years this firm had sold poisons for killing insects. After a trial, Bruno Tesch and his chief assistant were hanged. 

You might find heptachlor or heptachlor epoxide in the soil or air of homes treated for termites, dissolved in surface water or groundwater, or in the air near hazardous waste sites. You might also find heptachlor or its by-product, heptachlor epoxide, in plants and animals near hazardous waste sites. Heptachlor can no longer be used to kill insects on crops or in homes and buildings. However, heptachlor is still approved by EPA for killing fire ants in power transformers. More information on the... 

Qilorphenothane (DDT) kills insects after absorption of a very small amount, e.g via foot contact with... 

During the 1950s and 1960s there was an enormous increase in the use of chemicals in agriculture, industrial manufacturing, and around the home. We powdered our bodies with DDT to remove lice and spread DDT far and wide to control mosquitoes. We used other pesticides to kill insects and controlled weeds to improve crop yields. Lead was added to gasoline to make cars run better and added... 

The introduction of synthetic pesticides heralded a new era in which agricultural production flourished. However, the use of pesticides introduced unexpected problems. In the case of insecticides, beneficial as well as harmful Insects were killed. Insects rapidly developed resistance to the insecticides, requiring the introduction of new and more potent chemicals. 

The early development and present status of petroleum oils as insecticides for use on deciduous fruit trees are reviewed. The biological groups of insects most susceptible to oil sprays are listed. Factors affecting oil deposit are discussed and data are cited to establish relationships between oil deposit and control. The relationship between chemical composition and control efficiency is also discussed. The possible modes of action by which petroleum oils kill insects are considered. Specifications are given for improved dormant spray oil. Current recommendations ifor the use of oil sprays in control of fruit pests occurring in New York State are listed. The possibility of developing more effective hydrocarbon insecticides is discussed. 

As in the case of mode of action of ovicides, much work remains to be done before the mechanism whereby oils kill insects is clearly understood. 

Particle size of insecticidal sprays has a bearing on the ability of airborne sprays to be transported and deposited, on foliage injury, and on the efficiency of residues in killing insects. Each problem should be carefully analyzed for the particle-size requirements. 

Organophosphate and carbamate cholinesterase inhibitors (see Chapter 7) are widely used to kill insects and other pests. Most cases of serious organophosphate or carbamate poisoning result from intentional ingestion by a suicidal person, but poisoning has also occurred at work (pesticide application or packaging) or, rarely, as a result of food contamination or terrorist attack (eg, release of the chemical warfare nerve agent sarin in the Tokyo subway system in 1995). 

Insects and mites are animals and, traditionally, the most effective compounds for their control have been compounds that interfere with nerve function. Fundamentally, all animals have the same mechanisms for detecting and transmitting nerve impulses. Nerve-active compounds that kill insects will usually have some effects on mammals. 

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