DO NOW Form groups. Download ch.16 Notes

1. DO NOW Form groups. Download ch.16 Notes Download: Chapter Presentations (if you don’t have it saved) 1: blue – 2 2: green - 2 3: salmon - 2 4: purple - 3 5: white - 3 6: red - 2 7: yellow - 3 8: orange - 2

3. Desert Locust Ranges

4. Pests and Pest Control • The need for pest control • Promises and problems of the chemical approach • Alternative pest control methods • Socioeconomic issues in pest management • Pesticides and policy

5. The Need for Pest Control: Defining Pests • Any organism that has a negative effect on human health or economics • Any organism that is noxious, destructive, or troublesome • Plants or animals (see Fig. 16-2) • Formosan termite • Fire ants • Aedes mosquito • Medfly

6. Pest Control Purposes • Protect our food • Protect our health • Convenience

7. Pesticide Use in the United States

8. Different Philosophies of Pest Control • Chemical technology • Use of chemicals to kill large numbers of the pest • Short-term protection • Environmental and health consequences

9. Different Philosophies of Pest Control • Ecological pest management • Control based on pest life cycle and ecology • Control agent may be an organism or chemical (more on next slide)

10. Different Philosophies of Pest Control • Specific to pest and/or manipulate a part of the ecosystem • Emphasizes protection from pest • Integrated pest management: “using all suitable methods – chemical and ecological – in a way that brings about long-term management of pest populations and minimal environmental impact.”

11. Promises and Problems of the Chemical Approach • Development of chemical pesticides and their successes • Problems stemming from chemical pesticide use

12. Development of Chemical Pesticides • First-generation pesticides (inorganic) • First attempt at chemical technology • Toxic to humans and agricultural plants • Pests developed resistance

13. Development of Chemical Pesticides • Second-generation pesticides • Used after WW II • Organic chemical • Toxic to humans and agricultural plants • Pests developed resistance

14. The DDT Story • DDT: the magic bullet • Extremely toxic to insects; seemed nontoxic to humans and other mammals • Cheap • Broad-spectrum and persistent (more next slide)

15. The DDT Story • DDT: the magic bullet • Effective for disease prevention (typhus fever, malaria) • Expanded agricultural production • Paul Muller awarded Nobel prize in 1948

16. Aerial Spraying

18. Problems Stemming from Chemical Pesticide Use • Development of resistance by pests • Resurgences and secondary pest outbreaks • Adverse environmental and human health effects

19. Resistance • Chemical pesticides lose effectiveness • Resistant pest populations produce next generations

20. Genetics of Pest Resistance

21. Genetics of Pest Resistance

22. Resurgence and Secondary Outbreaks • Resurgences: after “eliminating” a pest, its population rebounds in even higher numbers than previous levels. • Secondary outbreaks: outbreaks of species’ populations that were not previously at pest levels.

23. The Bugs Are Coming! Time Magazine, July 12, 1976, page 38

25. The Pesticide Treadmill

26. Human Health Effects • Cancer, dermatitis, neurological disorder, birth defects, sterility, endocrine system disruption, immune system depression. • Agricultural workers suffer acute poisoning during pesticide application.

27. Human Health Effects • Aerial spraying and dumping bring pesticides in contact with families and children. • Soldiers exposed to agent orange in Vietnam suffered high rates of cancer and other diseases.

28. Environmental Effects • DDT led to the decline in populations of several bird species • Bald eagle • Peregrine falcon • Bioaccumulation • Biomagnification

29. Biomagnification

30. Nonpersistent Pesticides • Substitutes for banned pesticides • Breakdown after a few weeks • Can still be harmful because of: • Toxicity • Dosage • Location

31. Alternative Pest Control Methods • Cultural control • Control by natural enemies • Genetic control • Natural chemical control

32. Complex Life Cycle of Insects

33. Cultural Control

34. Genetic Control • Plants or animals are bred to be resistant to the attack of pests. • Chemical barriers. • Physical barriers.

35. Control Using Natural Enemies

36. Parasitic Wasps

37. Cactus-eating Moths

38. Genetic Control • Chemical barriers, e.g., Hessian fly • Physical barriers, e.g., sticky glandular hairs • Sterile males are released into pest population, e.g., botfly larvae • Genetic engineering, e.g., Bt Bacillus thuringiensis - a bacterium that produces a protein killing larvae of many insect pests.

39. Hessian Fly

40. Alfalfa Glandular Hairs

41. Bioengineered Potatoes

42. Natural Chemical Control • A volatile chemical produced by the opposite sex of a species which alters the reproductive behavior of the opposite sex. • Perfumes • Colognes • After shave • Natural body odors

43. Natural Chemical Control • Manipulation of pests’ hormones or pheromones to disrupt the life cycle. • Japanese beetle trap.

44. Socioeconomic Issues of Pest Management • Pressures to use pesticides • Integrated pest management • Organically grown food

45. The Economic Threshold

46. Integrated Pest Management (IPM) • An approach to controlling pest populations using all suitable methods - chemical and ecological - in a way that brings about long-term management of pest populations and also has minimal environmental impact

48. Organically Grown Food

49. Organically Grown Food • Employ traditional farming methods • Crop diversity • Lower crop yields and expenses • Richer field and orchard soil • Sales of organics now a $31 billion enterprise in the U.S. alone. • USDA Organic: Organic Foods Protection Act of 1990

50. Three Concerns • Pesticides evaluated for intended use and impacts on human health and the environment. • Protection and proper training of those who work with pesticides. • Public protection from risks of pesticide residues on food products.