Biological control

• Alien species = species which has accidentally or deliberately been introduced to an area that they are not naturally found in and causes harm or has a negative impact on environment
• Alien species = problematic -> may become invasive, outcompete native species, kill off native species (def for invasive species)
• Chemical pesticides-> used to kill pests that may eat crops
• dis of chem pesticides:

  • aren’t specific to one pest, may kill other non-invasive species
  • reduce biodiversity because they kill all of the pests in an area
  • some organisms can become resistant to the pesticides
  • expensive as it requires repeated application
• Advs of Chem pesticides:

  • readily available
  • easy to use
• Biological control = using living organisms to control the population size of a pest species
• For biological control, research has to be previously taken place to ensure that it can survive in the target environment
• Advs to biological control:

  • Specific - only kills the target species -> doesn’t decrease biodiversity
  • no chemicals are used
  • no resistance (pests cannot become resistant to their predator)
  • only needs to be introduced once
  • once set up, low cost
• Dis of biological control:

  • initial cost to research
  • pest not completely eradicated as it only controls population size
  • could become a pest itself
  • could introduce a disease
  • takes time to establish itself
• For a biological control to be introduced it must:

  • Survive in the environment
  • not become a pest itself
  • not harm any other non-pest, native species
  • not compete with other native species
  • not carry diseases