Chapter 17 by suchenfz

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									   Chapter 17

Pests and Pest Control
Pest Control: Pesticides

                       Worldwide, $37
                       billion were spent
                       on pesticides.

                       They protect crops,
                       but what are the
                       drawbacks?
   Chemical Control: Successes
• First Generation Pesticides: toxic heavy
      metals
• Second Generation Pesticides: synthetic
      organic chemicals
• DDT: toxic to insects, non-toxic to humans,
      cheap, persistent
     Chemical Control: Problems
•   Resistance
•   Secondary Outbreaks
•   Human Health: cancers, acute poisoning
•   Environmental Effects: non-target
    organisms, persistence
Chemical Control: DDT
                     DDT made its way
                     up the food chain
                     and killed animals
                     that people cared
                     about




                 Biological Magnification
          Alternative Methods
•   Cultural
•   Natural Enemies
•   Genetics
•   Natural Chemicals
    Alternative Methods: Cultural
•   Cleaning: remove things that entice pests
•   Insect screens: keep pests out of the house
•   Crop Rotation: avoid a buffet for insects
•   Lawn Care: leave the grass 3” long, avoid
       plants that attract pests (roses), allow
       diversity in the lawn
Alternative Methods: Natural Enemies

                           Predators and
                           parasites can often be
                           used to help control a
                           pest. Examples
                           include ladybugs for
                           scale insects, parasitic
                           wasps for caterpillars,
                           Brazilian weevils for
                           water hyacinth
  Alternative Methods: Genetics
• Chemical barriers through breeding
• Physical barriers through breeding
• Biotechnology: introducing novel genes
     into an organism
        Alternative Methods:
         Natural Chemicals

• Use an insect’s own pheromones against it
  – juvenile hormone
  – mate attractants
Socioeconomics: Pesticides
                             Pesticides will
                             only be
                             economical if
                             they keep a
                             pest below a
                             critical
                             threshold. If
                             the pest is
                             already below
                             the threshold
                             then pesticides
                             should not be
                             used.
Socioeconomics: Integrated Pest Management

                                   Crop
                                   rotation,
                                   polyculture,
                                   destruction
                                   of crop
                                   residues,
                                   predator
                                   populations,
                                   careful
                                   timing of
                                   planting and
                                   fertilizer
 Socioeconomics: Organic Food
• Grown without synthetic fertilizers or
     pesticides
• Higher cost
• The market share is growing
• Certification is an issue
             Public Policy
• Federal Insecticide, Fungicide, and
     Rodenticide Act: covers manufacture,
     use, and sale of pesticides
• Food Quality Protection Act: standards for
     chemicals on foods
• Developing Countries: informed permission
     for selling pesticides banned in the US
     to other countries
             Future Policy
• Reduce pesticide use
• Promote biological control
• Use of IPM
                Summary
• Pest Control: pesticides
• Chemical Control: successes, problems,
     DDT
• Alternative Methods: cultural, natural
     enemies, genetics, natural chemicals
• Socioeconomics: pesticides, integrated pest
     management, organic food
• Public Policy: current policy, future policy

								
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