Embed Size (px)
DESCRIPTION
Chapter 20 Pesticides and Pest Control. G. Tyler Miller’s Living in the Environment 13 th Edition. Pests. Compete with humans for food Invade lawns and gardens Destroy wood in houses Spread disease Are a nuisance May be controlled by natural enemies. Pesticides: Types. - PowerPoint PPT Presentation
Citation preview
Chapter 20Pesticides and Pest ControlChapter 20Pesticides and Pest Control
G. Tyler Miller’sLiving in the Environment
13th Edition
G. Tyler Miller’sLiving in the Environment
13th Edition
PestsPests
Compete with humans for food
Invade lawns and gardens Destroy wood in houses Spread disease Are a nuisance May be controlled by
natural enemies
Compete with humans for food
Invade lawns and gardens Destroy wood in houses Spread disease Are a nuisance May be controlled by
natural enemies
Pesticides: TypesPesticides: Types
Chemicals that kill undesirable organisms
-Insecticides (insects)
-Herbicides (weeds)
-Fungicides (fungus)
-Rodenticides (rats and mice)
Chemicals that kill undesirable organisms
-Insecticides (insects)
-Herbicides (weeds)
-Fungicides (fungus)
-Rodenticides (rats and mice)
See Table 20-1 p. 514See Table 20-1 p. 514
First Generation PesticidesFirst Generation Pesticides
• Primarily natural substances
• Sulfur, lead, arsenic, mercury
• Plant extracts: nicotine (tobacco), pyrethrum (chrysanthemum), rotenone (tropical legumes)
Plant extracts are degradable
• Primarily natural substances
• Sulfur, lead, arsenic, mercury
• Plant extracts: nicotine (tobacco), pyrethrum (chrysanthemum), rotenone (tropical legumes)
Plant extracts are degradable
Second Generation PesticidesSecond Generation Pesticides
Primarily synthetic organic compounds
Over 600 biologically-active compounds
Broad-spectrum agentsToxic to many
Narrow-spectrum agentsToxic to specific group
Target species/Nontarget species
Primarily synthetic organic compounds
Over 600 biologically-active compounds
Broad-spectrum agentsToxic to many
Narrow-spectrum agentsToxic to specific group
Target species/Nontarget species
See Table 20-1 p. 514See Table 20-1 p. 514
The Case for PesticidesThe Case for Pesticides
Save human lives
Increase supplies and lower cost of food
Work better and faster than alternatives
Health risks may be insignificant compared to benefits
Newer pesticides are becoming safer
New pesticides are used at lower rates
Save human lives
Increase supplies and lower cost of food
Work better and faster than alternatives
Health risks may be insignificant compared to benefits
Newer pesticides are becoming safer
New pesticides are used at lower rates
Characteristics of an Ideal PesticideCharacteristics of an Ideal Pesticide
Kill only target pests
Do not harm other species
Break down quickly
Do not cause genetic resistance
Are more cost-effective than doing nothing
Kill only target pests
Do not harm other species
Break down quickly
Do not cause genetic resistance
Are more cost-effective than doing nothing
Individuals Matter: Rachel CarsonIndividuals Matter: Rachel Carson
• Wrote Silent Spring which introduced the U.S. to the dangers of the pesticide DDT and related compounds to the environment.
The Case Against PesticidesThe Case Against Pesticides
Genetic resistance
Can kill nontarget and natural control species
Can cause an increase in other pest species
The pesticide treadmill Once started we must continue, often
at higher and higher rates
Pesticides do not stay put
Can harm wildlife
Potential human health threats
Genetic resistance
Can kill nontarget and natural control species
Can cause an increase in other pest species
The pesticide treadmill Once started we must continue, often
at higher and higher rates
Pesticides do not stay put
Can harm wildlife
Potential human health threats
Pesticide Regulation in the United StatesPesticide Regulation in the United States
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)•Established 1947/Amended 1972•EPA reviews evaluation of chemicals•Sets tolerance levels•Inadequate and poorly enforced
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA)•Established 1947/Amended 1972•EPA reviews evaluation of chemicals•Sets tolerance levels•Inadequate and poorly enforced
Pesticide Regulation in the United StatesPesticide Regulation in the United States
Food Quality Protection Act (FQPA)- Established in 1996- New standards for pesticide tolerance based on no harm to human health
Food Quality Protection Act (FQPA)- Established in 1996- New standards for pesticide tolerance based on no harm to human health
Other Ways to Control PestsOther Ways to Control Pests
Economic threshold- The point at which economic losses caused by pest damage outweigh the
cost of applying a pesticide.
Adjusting cultivation practices
Use genetically-resistant plants
Biological pest control
Economic threshold- The point at which economic losses caused by pest damage outweigh the
cost of applying a pesticide.
Adjusting cultivation practices
Use genetically-resistant plants
Biological pest control
Other Ways to Control PestsOther Ways to Control Pests
• Biological pest control: Wasp parasitizing a gypsy moth caterpillar.
Other Ways to Control PestsOther Ways to Control Pests
• Genetic engineering can be used to develop pest and disease resistant crop strains.
• Both tomato plants were exposed to destructive caterpillars. The genetically altered plant (right) shows little damage. Contains a gene from bacteria called the Bt gene.
Other Ways to Control PestsOther Ways to Control Pests
Biopesticides
Insect birth control
Hormones and pheromones
Ionizing radiation
Biopesticides
Insect birth control
Hormones and pheromones
Ionizing radiation
Integrated Pest ManagementIntegrated Pest Management Ecological system approach
Reduce pest populations to economic threshold
Field monitoring of pest populations
Use of biological agents
Chemical pesticides are last resort
Ecological system approach
Reduce pest populations to economic threshold
Field monitoring of pest populations
Use of biological agents
Chemical pesticides are last resort
