1. CHAPTER 15 PEST CONTROL -In the US 13% OF ALL CROPS DAMAGED BY INSECTS World Wide 33%

2. PEST CONTROL  A pest –organism that occurs where unwanted or in amounts unwanted or in amounts large enough to harm ecosystem. large enough to harm ecosystem.

3. Wild Plants Wild plants naturally have greater protection from pests than non-genetically altered planted crops. Why?  Wild plants go throughout the landscape  Crop plants grow all together in a field –One stop source for food  Wild plants protected from pests by pest predators  Wild plants have evolved defenses to many pests

4. PESTICIDES  Pesticides (chemicals) Used to kill pests.  Last 50 years many new pesticides, increased crop yields.

5. What is the downside of pesticide use? –Can harm beneficial plants and insects, wildlife and people –Can degrade the soil

6. What does pesticide resistant mean?  overtime spraying large amounts of pesticide usually makes the problem worse  Pest populations may evolve the ability to survive exposure to a particular pesticide  More than 500 pests have developed resistances to pesticides.

7. Pesticides  Human Health Concerns  In areas where crops are sprayed w/pesticides, children have higher rates of cancers. of cancers.  Workers develop nervous system disorders (farm workers and workers in the pesticide factory are affected.) –Constant exposure (touching, breathing) to the pesticide causes build up of the chemical in the people, animals or plants

8. Pollution and Pesticides  Pesticides should break down into harmless chemicals easily and quickly  Problems occur with persistent pesticides –A pesticide that does not break down easily or quickly into the environment  As a result they accumulate in the water and soil  Some have been banned in the US –DDT

9. Biological Pest Control  Is the use of living organisms to control pests –Every pest has enemies in the wild  Lady bugs eat aphids  Pathogens: organisms that cause disease –Can be used to control pests –Most commonly used is bacterium Bt.  Kills caterpillars of moths and butterflies.

10. Biological Pesticide Control  Plant Defenses –Scientists and farmers have bread plants with natural defenses  Genetically altered plants can be made resistant to fungi, worms and viruses.

11. Biological Pest Control Other defenses: spines, tough skin and chemical compounds that pests do not like. spines, tough skin and chemical compounds that pests do not like.  Chemicals from plants: –Chemicals contained in chrysanthemums sold as pesticides. –These chemicals are biodegradable.

12. Biological Pest Control Disrupting Insect Breeding Disrupting Insect Breeding  Growth Regulators - Crops are bred with a gene that when expressed in a plant and consumed will disrupt the consumers breeding abilities.  Pheromones – Chemicals produced by an organism to affect another. Farmers treat crops w/pheromones to confuse moths and prevent mating. –Japanese beetle traps