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Pests and Pest Control. Pests. Any troublesome, destructive , or annoying organism Insects eat about 13% of all crops in North America Only 1/8 th of insects are pests. Pests. Many insects are very beneficial . keep soil “healthy” maintain food crops pollinators. Pesticides.
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Pests • Any troublesome, destructive, or annoying organism • Insects eat about 13% of all crops in North America • Only 1/8th of insects are pests.
Pests • Many insects are very beneficial. • keep soil “healthy” • maintain food crops • pollinators
Pesticides • Chemicals that kill insects, weeds, and other crop pests • Humans have created very effective pesticides • Pesticides can harm beneficial plants, insects, wildlife, and even people
Pesticide Resistance • The ability of pests to survive exposure to a particular pesticide. • Occurs when large amounts are sprayed continually • Pest population evolve resistance to the pesticide
Human Health Concerns • Pesticides are designed to kill organisms • May also be dangerous to humans • Cancer rates among children in areas that use large amounts of pesticides are higher than the national average • Nervous systems disorders may be common • Pesticide factory workers may become ill • Accidental chemical leaks may endanger people in the area • Safety guidelines must be followed to protect people
Persistent Pesticides • A pesticide is persistent if it does not break down easily or quickly in the environment. • Accumulates in the water and soil • Many remain in the environment for many years
A Harmful Pesticide • Chlorinated Hydrocarbons • cheap, easy to use, kills many different insects, kills long after application, doesn’t wash away by rain, may not be very toxic to humans • Example: DDT • was banned in the United States in 1972 but is still found in foods decades later • stored in body fats
Bioaccumulation • When something, such as a pesticide, becomes more and more concentrated as it moves up the food chain • DDT caused eggshell thinning in eagles and ospreys
Biological Pest Control • Use of living organisms to control pests • Natural Predators • Pathogens • VNT • Natural Chemicals • Growth Regulators
Pathogens • Organisms that cause disease • Bacillus thuringiensis is a bacterium that kills caterpillars
VNT • plant varieties that are resistant to certain fungi, worms, and viruses
Natural Chemicals • From plants are sold as pesticides • less harmful to humans and animals and is biodegradable Example: • chrysanthemums
Growth Regulators • Chemicals that interfere with the life cycle • pheromones • sterilize males
Integrated Pest Management (IPM) • Aims to reduce pest damage • Uses different management techniques according to the management goal and species involved • Used at appropriate times in the growing season
Steps of an IPM • Monitor crops from time of planting • Identify pests • Create a program • First try biological methods • Cultivation controls • Vacuuming pests • Small amounts of pesticide as a last resort • Change the pesticide overtime to reduce pesticide resistance
Genetic Engineering • Using technology in which genetic material in a living cell is modified. • Take genes from one organism and introduce them into another organism • Creates genetically modified (GM) plants • Used for pesticide resistance • Increased “life” of produce • Improved taste
Genetic Engineering • Many foods are genetically engineered • Many have not been fully tested for environmental impacts • May cause future problems
Sustainable Agriculture • Farming that conserves natural resources and helps keep the land productive indefinitely • Minimizes the use of: • Energy • Water • Pesticides • Fertilizers