Control of Agricultural Pests


An organism that competes with humans for food or space and can be a danger to health


Poisonous chemicals that kill pests

Chemical Control

Disadvantages of using chemical control:

  • Must be reapplied at intervals making it very expensive
  • Pests develop genetic resistance and new pesticides have to be developed

Biological Control

Pests can be controlled by using organisms hat are either predators or parasites of the pest organism.

The aim is to control the pest, not to eradicate it.

If the pest was reduced to such an extent that there was insufficient food for its predators, its predators would die.

The surviving pests would then be able to multiply unchecked.

The control species has to be chosen carefully, to ensure that it:

  • Attacks the pest only and not other native species
  • Will not itself become a pest due to lack of predators or parasites
  • Can survive in the new environment
  • Does not carry disease

Disadvantages of using biological control:

  • They do not act as quickly
  • There is sometimes an interval of time between introducing the control organism and a significant reduction in the pest control
  • A control organism may itself become a pest