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Unformatted text preview: 1 Overview Ch. 13: Pests & Pest Control Locusts Switch from solitary to gregarious Devastate local economies The Need for Pest Control Chemical Treatment Alternative Methods Socioeconomic Issues Pesticides & Policy Importance of Pest Control Pests Any organism that is noxious, destructive, or troublesome Agricultural pests Weeds Control Protect our food Protect our health For convenience Pests destroy 37% of agricultural potential in U.S. Loss of $122 billion Use 888 million pounds of herbicides & pesticides Cost $11.1 billion Monocultures & genetically identical 31% (1950) b 37% lost to pests Different Philosophies Chemical treatment Short-term protection Side effects Ecological control Long-lasting protection Uses ecological relationships to control pest population Integrated pest management (IPM) Control pests using all suitable methods Long-term management of pest populations Minimal environmental impact Chemical Treatment: The Promise Pesticide development 1 st-generation Toxic heavy metals Resistance: 90% b 3% effective 2 nd-generation Synthetic organic chemistry Successes: DDT Broad spectrum & persistent Controlled insects Disease carriers in WWII (& today in 22 countries with malaria) Defoliation of forests Agricultural pests EPA Pesticide Program Regulates 18,000 pesticide products Some Commonly Used Pesticides 1 2 1 2 3 1 2 4 1 2 5 2 Chemical Treatment: Problems Resistance in pests Evolution at work Pesticides & herbicides are strong selective pressures for survival of resistant varieties Especially problematic when used exclusively & in large quantities E.g. Roundup & Bt crops that are herbicide resistant (HT) Natural predators Resurgences Pest population recovers at much higher levels Secondary-pest outbreaks Other pests have a population explosion Pesticide Treadmill Chemical Treatment: Problems Health effects Acute effects Poisonings of farm workers & employees of pesticide companies...
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This note was uploaded on 01/12/2012 for the course BIOLOGY 36 taught by Professor Teresafinnern during the Fall '11 term at Riverside Community College.
- Fall '11