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Introduction

Sophie Fielding The issues associated with pest control Pests can be kept under control in many ways. However, the main way to kill off pests is to use a substance called a pesticide. A pesticide is a substance produced to kill or repel any pest. Pests can be insects, mice, rabbits or other animals, weeds, fungi or microorganisms for example bacteria and viruses. The term pesticides covers a whole range off substances used to control pests some of which are insecticides (these kill insects), herbicides (these kill plants/weeds) and fungicides (these destroy fungi). "The term pesticide is an all embracing word for herbicides (which kill plants), insecticides (which kill insects), fungicides (which act on fungi) and so on." (Quote from Taylor, Green and Stout: biological sciences 1 & 2 page 334) The table below shows some examples of pesticides and what they do. Pesticide What it does Weed killers Also known as herbicides Insecticides Insect pest killers Fungicides Kill fungi, including mould Acaricides Kill spiders Nematocides Kill round, thread or eel worms Rodentcides Kill mice and rats Algicides Kill algae Miticides Kill mites Molluscicides Kill snails and slugs Growth regulators Stimulate or retard plant growth Defoliants Remove plant leaves Desiccants Speed plant drying Attractants Attract insects e.g. ...read more.

Middle

This form of control was attempted in Australia when the Cane toad was introduced from Hawaii to control the Cane grubs, which were destroying Cane crops. However, the Cane toads did not eat the grubs and could not be removed because they had multiplied so they gradually out competed all of the native species and because there was no natural predators for the toad the population kept growing. This issue is very serious as it altered the natural habitat in Australia as far as wildlife is concerned because of a foreign species being used to control a native species when all of the consequences were not thought about (class notes) "Cane toad was introduced as a means of biological control the cane toad is now a predator of native species." (Quote: Toole and Toole: understanding biology page 381) * Chemical control: this is generally effective, cheap, and safe if handled correctly. However, they can have adverse effects on nature. Chlorinated hydrocarbon insecticides such as DDT, for example is toxic to insects, fish, and other wildlife; the insecticides may be found in meat and milk, or they may lie in the soil for many years and cause problems. ...read more.

Conclusion

Some botanical pesticides are toxic to fish and other cold-blooded creatures and should be treated with care. The botanical insecticides break down readily in soil and are not stored in plant or animal tissue. Often their effects are not as long lasting as those of synthetic pesticides. For example, Pyrethrum works against Pickleworms, aphids, leafhoppers, spider mites, harlequin bugs, cabbageworms, Mexican bean beetles, flea beetles, flies, and squash bugs. Advantages of using biopesticides include: Biopesticides are usually inherently less harmful than conventional pesticides. They generally affect only the target pest and closely related organisms, in contrast to broad spectrum, conventional pesticides that may affect organisms as different as birds, insects, and mammals. Biopesticides often are effective in very small quantities and often decompose quickly, thereby resulting in lower exposures and largely avoiding the pollution problems caused by conventional pesticides. "When used as a component of Integrated Pest Management (IPM) programs, biopesticides can greatly decrease the use of conventional pesticides, while crop yields remain high." (Quote: Britannica encyclopaedia CD-ROM: search: what is integrated control?) Conclusion From what I have looked at and discussed during this essay you can see that pesticides have an intended good purpose however, they have some seriously bad effects and should be permanently banned from being used then there would be less debate over whether or not certain fruits from certain places are safe to ear. ...read more.

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