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Pesticide Use. LT 7C : Identify and describe major pesticides, classify them as either narrow or broad spectrum and discuss the advantages and disadvantages of each. What are pests?. Pests are any species that interferes with human welfare by: competing with us for food
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Pesticide Use LT 7C: Identify and describe major pesticides, classify them as either narrow or broad spectrum and discuss the advantages and disadvantages of each.
What are pests? • Pests are any species that interferes with human welfare by: • competing with us for food • invading lawns and gardens • destroying building materials • Spreading disease • Invading ecosystems • Being a nuisance
Controlling Pests • Naturally through predators, parasites and disease organisms • Ex: World’s 30,000 known species of spiders kill far more insects every year than humans do by using chemicals
Pesticides • Chemicals used to kill or control populations of organisms that we consider undesirable. • Common Types: • Insecticides • Herbicides • Fungicides • Rodenticides
Pesticides • First generation • 1600’s • Natural chemicals borrowed from plants • Nicotine sulfate from tobacco leaves
Pesticides • Second generation • 1930-1970s • Produced in a laboratory • Ex: DDT • World’s most-used pesticide • Hazardous to humans strict control over its use
Pesticides • Biopesticides • Since 1970 • Natural repellents, poisons and chemicals made by plants
Broad vs Narrow Spectrum • Broad: toxic to may pests including beneficial species • Ex: DDT, malathion, prathion • Narrow (selective): effective against a narrowly defined group of organisms • Ex: Algicides, fungicides, avicides
Conventional Chemical Pesticies • Disadvantages • Promote genetic resistance • Kill natural pest enemies • Pollute the environment • Can harm wildlife and people • Expensive for farmers • Advantages • Save human lives • Increase food supplies • Profitable • Work fast • Safe if used properly
Effectiveness of Pesticides • Not effective in reducing U.S. crop losses • Genetic resistance • Reduction of natural predators
Laws and Treaties • Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) • Passed in 1947 • Amended in 1972 • Regulate the sale and use of pesticides • Administered by the EPA, USDA and FDA • Banned or severely restricted use of 64 active pesticides between 1972 and 2009 • Studies by NAS suggest that federals regulating pesticide use in the US are inadequate and poorly enforced
Laws and Treaties • Food Quality Protection Act • Passed in 1996 • Requires the EPA to reduce the allowed levels of pesticide residues in food by a factor of 10 where there is inadequate information on the potentially harmful effects on children • International treaties • 1998 • More than 50 countries • Informed consent from importing countries • 2000 • More than 100 countries • Ban or phase out use of 12 especially hazardous persistent organic pollutants (POPs) including DDT • US did not ratify agreement
Alternative to Conventional Pesticides • Increase use of biological, ecological and other alternative methods for controlling pests • Fool the pest • Provide homes for pest enemies • Implant genetic resistance • Bring in natural enemies • Use insect perfumes • Bring in the hormones • Reduce use of synthetic herbicides