The Pesticide Dilemma

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The Pesticide Dilemma
Chapter 12
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Types of Pesticides
23.1

• INSECTICIDES
• Kill insects by blocking reproduction, clogging
  airways or disrupting nervous system
• HERBICIDES
• Kill weeds by disrupting metabolism growth
• FUNGICIDES
• Fungus killers
• RODENTICIDES
• Rat mouse killers

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What is a Pesticide?
23.2

• First-Generation Pesticides
• Inorganic compounds (e.g., lead, mercury)
• Botanicals (e.g., nicotine, pyrethrin)

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What is a Pesticide?

• Second-Generation Pesticides
• Synthetic botanicals (e.g., pyrethroids)
• DDT

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MAJOR CLASSES

• The Major Groups of Insecticides
• Chlorinated hydrocarbon (e.g., DDT)
• Organophosphates (e.g., malathion)
• Carbamates (e.g., carbaryl)

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Table 23-1Page 520
Table 23-1 Major Types of Pesticides
Type Insecticides Chlorinated hydrocarbons Org
anophosphates Carbamates Botanicals Mic
robotanicals
Examples DDT, aldrin, dieldrin, toxaphene,
lindane, chlordane, methoxychlor,
mirex Malathion, parathion, diazinon, TEPP,
DDVP,mevinphos Aldicarb, carbaryl (Sevin),
propoxur, maneb, zineb Rotenone, pyrethrum, and
camphor extracted from plants, synthetic
pyrethroids (variations of pyrethrum), rotenoids
(variations of rotenone), and neonicotinoids (vari
ations of nicotine) Various bacteria, fungi,
protozoa
Persistence High (215 years) Low to
moderate (12 weeks), but some can last several
years Low (days to weeks) Low (days to
weeks) Low (days to weeks)
Biologically Magnified? Yes No No No
No
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Table 23-1Page 520
Table 23-1 Major Types of Pesticides
Type Herbicides Contact chemicals Systemic
chemicals Soil sterilants Fungicides Various
chemicals Fumigants Various chemicals
Examples Atrazine, simazine,
paraquat 2,4-D, 2,4,5-T, Silvex,
diuron, daminozide (Alar), alachlor
(Lasso), glyphosate (Roundup) Tribulan,
diphenamid, dalapon, butylate Captan,
pentachlorophenol, zeneb, methyl bromide, carbon
bisulfide Carbon tetrachloride, ethylene
dibromide, methyl bromide
Persistence Low (days to weeks) Mostly
low (days to weeks) Low (days) Most low
(days) Mostly high
Biologically Magnified? No No No No
Yes (for most)
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What is a Pesticide?

• The Major Kinds of Herbicides
• Selective herbicides
• (e.g., 2,4-D kills broad-leaved plants)
• Nonselective herbicides
• (e.g., glyphosate, aka Round-UpTM)

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Benefits and Problems with Pesticides

• Benefit Disease Control

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Benefits and Problems with Pesticides

• Benefit Crop production
• Farmers save 3 - 5 in crops for every 1
  invested into pesticides

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Benefits and Problems with Pesticides

• Problem Evolution of Genetic Resistance

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Benefits and Problems with Pesticides

• Problem Evolution of Genetic Resistance
• Creates a pesticide treadmill

Pesticide application
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Benefits and Problems with Pesticides

• Problem Evolution of Genetic Resistance
• Resistance Management

• Create a refuge (no pesticide applied)
• Avoid repeated use of same pesticide

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Benefits and Problems with Pesticides

• Problem Imbalances in the Ecosystem

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Benefits and Problems with Pesticides

• Problem Imbalances in the Ecosystem
• Creation of New Pests

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Benefits and Problems with Pesticides

• Problem Persistence, Bioaccumulation, and
  Biological Magnification

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Benefits and Problems with Pesticides

• Problem Mobility in the Environment

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Risks of Pesticides to Human Health

• Short-term Effects of Pesticides
• Handling of food with pesticide residue

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Risks of Pesticides to Human Health

• Short-term Effects of Pesticides
• Case-in-Point The Bhopal Disaster

• 40 tons of methyl isocyanate gas released
• 600,000 people exposed
• 2,500 immediately killed
• 2,500 more killed through time
• 50,000-60,000 have serious health problems

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Risks of Pesticides to Human Health

• Long-term Effects of Pesticides
• Potentially higher risk of cancer
• Sterility
• Miscarriage / birth defects
• Potentially higher risk for Parkinsons disease

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Alternatives to Pesticides

• Using Cultivation Methods to Control Pests
• Interplant mixtures of plants
• Strip cutting
• Planting, fertilizing, and irrigating at proper
  time
• Crop rotation

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Alternatives to Pesticides

• Biological Controls
• Using naturally occurring diseases, parasites,
  or predators to control a pest
• Pheromones and Hormones
• Use pheromones to attract insects to traps
• Synthetic hormones induce abnormal development
• Reproductive Controls
• Sterile-male technique inundate pest
  population with large numbers of sterile males

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Alternatives to Pesticides

• Genetic Controls
• Using Genetically Modified plants (GMOs)
• Case-in-Point Bt, Its Potential and Problems
• Genetically modified corn to produce Bt toxin
• Potential problem may affect non-target
  species, such as monarch butterfly
• Quarantine

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Alternatives to Pesticides

• Integrated Pest Management

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Alternatives to Pesticides

• Integrated Pest Management

Rice Production in Indonesia
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Alternatives to Pesticides

• Irradiating Foods
• Predominantly used on meats
• Kills many microorganisms

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FEDERAL INSECTICIDE, FUNGICIDE, AND RODENTICIDE
ACT (FIFRA)

• The primary focus of FIFRA was to provide
  federal control of pesticide distribution, sale,
  and use
• EPA was given authority under FIFRA not only to
  study the consequences of pesticide usage but
  also to require users to register when purchasing
  pesticides
• EPA is required to make instructional materials
  concerning integrated pest management (IPM)
  techniques available to individuals at their
  request

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Laws Controlling Pesticide Use

• Food, Drug, and Cosmetics Act (1938)
• Pesticide Chemicals Amendment (1954)
• Delaney Cause (1958)
• Federal Insecticide, Fungicide, and Rodenticide
  Act (1947)

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Laws Controlling Pesticide Use

• Food, Drug, and Cosmetics Act (1938)
• Pesticide Chemicals Amendment (1954)
• Delaney Cause (1958)
• Federal Insecticide, Fungicide, and Rodenticide
  Act (1947)
• Food Quality Protection Act (1996)

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The Manufacture and Use of Banned Pesticides

• Some US companies still make banned or seriously
  restricted pesticides and export the product.
• This can potentially lead to the importation of
  food tainted with banned pesticides

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The Manufacture and Use of Banned Pesticides

• The Global Ban of Persistent Organic Pollutants

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IPM is

• A pest management philosophy that utilizes all
  suitable pest management techniques and methods
  to keep pest populations below economically
  injurious levels. Each pest management technique
  must be environmentally sound and compatible with
  producer objectives.

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WHAT IS IPM?

• IPM utilizes a combination of
• Preventive measures
• Monitoring
• Control techniques
• IPMs goal is to suppress pests by the least
  toxic measures
• IPM does not exclude the use of chemical
  pesticides, but utilizes them sparingly and only
  as a last resort