Pest control refers to the regulation or management of another species
defined as a pest, usually because it is detrimental to a person's
health, the ecology or the economy.
Pest control is at least as old as agriculture. In order to maximize
food production, it is necessary to protect crops from competing
species of plants, as well as from herbivores competing with humans.
This can be done with conventional, chemical or biological weapons.
The conventional approach was probably the first to be employed,
since it is comparatively easy to destroy weeds by burning them
or plowing them under, and to kill larger competing herbivores,
such as crows and other birds eating seeds. Techniques such as crop
rotation, companion planting, also known as intercropping or mixed
cropping, and the selective breeding of pest-resistant cultivars
also have a long history.
Many pests have only become a problem because of the direct actions
of humans. Modifying these actions can often substancially reduce
the pest problem. In the USA, raccoons caused a nuisance by tearing
open refuse sacks. Many householders introduced bins with locking
lids, which deterred the raccoons from visiting. House flies tend
to accumulate wherever there is human activity and is virtually
a global phenomenon, especially where food or food waste is exposed.
Fly killers or fly traps are often used to deal with them in homes
and businesses.
Seagulls have become a pest at many seaside resorts. Tourists would
often feed the birds with scraps of fish and chips, and before long,
the birds would become dependent on this food source and act aggressively
towards humans. Many local authorities have now erected signs warning
visitors not to feed the seagulls.
Chemical pest control dates back 4,500 years, when the Sumerians
used sulfur compounds as insecticides. The Rig Veda, which is about
4,000 years old, also mentions the use of poisonous plants for pest
control. And the ancient Chinese and Egyptians are also known to
have used chemical pest control. But it was only with the industrialization
and mechanization of agriculture in the 18th and 19th century, and
the introduction of the insecticides pyrethrum and derris that chemical
pest control became the method of choice. In the 20th century, the
discovery of several synthetic insecticides, such as DDT, and herbicides
boosted this development. Chemical pest control is still the predominant
type of pest control today, although its long-term effects led to
a renewed interest in traditional and biological pest control towards
the end of the 20th century.
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