Pest Control

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Pest Control
2014-06-05 03:09:02
Biology Productivity camturnbull

AQA BIOL4 Productivity
Show Answers:

  1. What are pesticides?
    Chemicals which kill insects
  2. What are the advantages of pesticides?
    • Can potentially kill all pests on a crop 
    • Starts working immediately
  3. What are the disadvantages of pesticides?
    • Leaves residue on crops which can be poisonous to humans
    • Will kill all insect species including helpful ones that eat other insects or pollinators, this also reduces food supplies for consumers such as birds
    • Insects can evolve resistance to the pesticide
    • Vary in how long they take to be broken down by bacterial enzymes and biodegrade
  4. How could the use of a pesticide lead to bioaccumulation?
    • If used in low concentrations some pests are not killed but contain low concentrations of the chemical
    • Predators such as birds eat many of these insects and the pesticide accumulates in their fat stores
    • Large predators eat many of the birds and levels of the pesticide in fat stores becomes fatally high
  5. What is a biological control?
    The introduction of a natural predator or parasite of the insect pest that will kill it
  6. What are the advantages of biological control?
    • It is specific to the pest species 
    • Cheaper as it only needs to be applied once and it can then reproduce rather than regular applications of chemicals
    • Reduces the use of insecticides so pests are less likely to develop resistance 
    • No toxic residue left on plants
  7. What are the disadvantages of biological controls?
    • Takes time for the biological control organisms to reach numbers that reduce pest numbers
    • Pest numbers will never reach 0 due to predator-prey relationships 
    • Control organism may become a pest due to the absence of a natural predator (cane toad)
  8. What does integrated pest management combine?
    • Chemical pesticides (starts work immediately whilst control organisms are reproducing)
    • Biological control
    • Selecting crops for pest resistance 
    • Providing habitats for natural predators (hedgerows)