Monday, February 13, 2012

5.4b Biological control

Understand the reasons for pest control and the advantages and disadvantages of using pesticides and biological control with crop plants

1. Pest numbers can be reduced by using using another organism, rather than a toxic chemical.

2. Method examples:

a) introducing a natural predator - ladybirds control population of aphids in orange groves.

b) introducing a herbivore - moth controls the prickly pear (weed) in grazing lands of Australia.

  • no toxic chemical
  • less impact on wildlife + man

  • not 100% efficient
  • difficult to control - danger 
  • difficult to match a predator to a prey.  

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