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  • Publicado : 31 de mayo de 2011
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Task 1
What is a pest?

|Pests | |Organisms that damage crops, forests or property are called pests. Pests |
|What? | |also cause diseases in humans, pets, and farm animals. Plants and animals |
|-cause damage or disease | |are the two main types of peststhat affect humans. |
|Types: | | |
|-plants | | |
|-animals | ||

|Plants | |Plant pests are called weeds. Weeds, like dandelions, often grow where we |
|What? | |plant our vegetables, trees and flowers. Weeds often steal space, sunlight, |
|-weeds | |water andnutrients from vegetable gardens and flower beds. This prevents |
|Damage: | |more valuable plants from growing properly. Weeds are difficult to get rid of|
|-valuable plants | |because most grow quickly and reproduce in large numbers. A single weed |
|Difficulties: ||produces hundreds of seeds. These seeds are spread over long distances by the|
|-grow quickly | |wind or small animals. Seeds can remain in the soil for years and survive |
|-produce hundreds of seeds | |harsh climates. They sprout and take root when weather conditions become |
|-spread over long distances| |favourable. |
|-remain for years | | |
|-survive harsh climates | | |

|Animals| |Animal pests include insects, fish, birds, and mammals. Most animal pests |
|What? | |feed on vegetation like crops, trees, and grains and some spread diseases. |
|-insects, birds, fish and mammals | |In small numbers, they are usually not a problem. However, certain animal |
|Damages:| |pests are able to mature and reproduce rapidly. For example, rats and |
|-valuable crops | |houseflies reproduce many times in a single year. This is especially true if|
|-spread diseases | |they have an adequate food supply. Consequently, small numbers of pests can ||Difficulties: | |soon become large, unmanageable populations. |
|-tend to be small | | |
|-mature and reproduce rapidly | | ||-become large populations | | |
|Pest Control | |Large pest populations are a major concern to humans because of their |
|Prevent: | |negative effects. Therefore humans try to control and even...
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