1. Pesticides and Pest Control G. Tyler Miller’s Living in the Environment 13 th Edition Chapter 20 G. Tyler Miller’s Living in the Environment 13 th Edition Chapter 20

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3. Key Concepts  Types and characteristics of pesticides  Pros and cons of using pesticides  Pesticide regulation in the US  Alternatives to chemical pesticides

4. What is a Pest?  Compete with humans for food  Invade lawns and gardens  Destroy wood in houses  Spread disease  Are a nuisance  May be controlled by natural enemies

5. Natural Ecosystem (Polyculture) Natural enemies of pests control 50 – 90% of pest species (Earth’s ecological services) Natural enemies of pests prevent any one pest species from taking control for very long

6. Pesticides: Types  Chemicals that kill undesirable organisms  Insecticides  Herbicides  Fungicides  Rodenticides

7. First Generation Pesticides  Primarily natural substances  Sulfur, lead, arsenic, mercury  Plant extracts: nicotine, pyrethrum, rotenone (from tobacco, chrysanthemums, and tropical forest legume roots, respectively.)  Plant extracts: nicotine, pyrethrum, rotenone (from tobacco, chrysanthemums, and tropical forest legume roots, respectively.)  Plant extracts are degradable

8. Second Generation Pesticides  Primarily synthetic organic compounds  630 biologically-active compounds  Broad-spectrum agents  Narrow-spectrum agents  Target species  Nontarget species

9. Major Types of Insecticides Chlorinated Hydrocarbons –DDT –Highly Persistent (2-15 years) Organophosphates –Malathion –Moderately Persistent (1-2 weeks) Carbamates –Sevin –Low Persistence (days-weeks) Botanicals –Rotenone, pyrethrum –Low Persistence (days-weeks)

10. The Case for Pesticides  Save human lives  Malaria (mosquito)  Bubonic plague (rat fleas)  Typhus (body lice and fleas)  Sleeping sickness (tsetse fly)  Save human lives  Malaria (mosquito)  Bubonic plague (rat fleas)  Typhus (body lice and fleas)  Sleeping sickness (tsetse fly)  Increase supplies and lower cost of food  55% of world’s potential food supply is lost to pests  Without pesticides it would be worse  Increase supplies and lower cost of food  55% of world’s potential food supply is lost to pests  Without pesticides it would be worse

11. The Case for Pesticides  Work better and faster than alternatives  Health risks may be insignificant compared to benefits  Newer pesticides are becoming safer  New pesticides are used at lower rates

12. Grasshopper Gypsy moth caterpillar MAJOR PESTS

13. European red mite MAJOR PESTS

14. Boll weevil Pink bollworm ranges overlap MAJOR PESTS

15. BOLL WEEVIL

16. Boll Weevil Lay thousands of eggs every 21 days 6 generations per growing season 25% of pesticide use in US to control the cotton boll weevil Approximately 0.24 pounds of pesticides to make one cotton T-shirt

17. Characteristics of an Ideal Pesticide  Kill only target pests  Harm no other species  Break down quickly  Not cause genetic resistance  Be more cost-effective than doing nothing

18. The Case Against Pesticides  Genetic resistance (directional natural selection)  Can kill nontarget and natural control species  Can cause an increase in other pest species  The pesticide treadmill  Pesticides do not stay put  Can harm wildlife (pollinators and insect eaters)  Potential human health threats

19. 600 500 400 300 200 100 0 1950196019701980199020002010 Year Number of species Boll weevilGypsy moth caterpillar Insects and mites Weeds Plant diseases Rise of Genetic Resistance to Pesticides

20. Pesticide Regulation in the United States  Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) (1947, 1972)  Tolerance levels: specify the amount of pesticide residue that can legally remain on a crop when the consumer eats it  Tolerance levels: specify the amount of pesticide residue that can legally remain on a crop when the consumer eats it  EPA Evaluation of chemicals for toxicity

21. Good News Between 1972 and 2001, the EPA banned or severely restricted the use of 56 active pesticide ingredients –Most chlorinated hydrocarbon insecticides –Several carbamates and organophosphates –HOWEVER: they may still be manufactured in US and exported to other countries…..Circle of Poison

22. Bad News Less than 10% of the 600 active ingredients used in pesticides have been evaluated fully. –165 are suspected human carcinogens –Missouri study showed a connection between childhood brain cancer and pesticide use in home –Multiple studies have shown connections between pesticide use and various types of cancers

23. Good News 1996 Food Quality Protection Act (FQPA) –Requires new standards for pesticide tolerance levels –Requires manufacturers to demonstrate safety for infants and children –Allows EPA to apply an additional 10-fold safety factor –Requires EPA to consider exposure to more than one pesticide when setting tolerance levels

24. Other Ways to Control Pests  Economic threshold: reduce crop damage to an economically tolerable level  Economic threshold: reduce crop damage to an economically tolerable level  Adjusting cultivation practices  Use genetically-resistant plants  Biological pest control  Biopesticides  Insect birth control  Hormones and pheromones  Ionizing radiation (gamma)

25. Figure 20-8 Page 521

26. DO NOT POST TO INTERNET

27. Integrated Pest Management (IPM)  Ecological system approach  Reduce pest populations to economic threshold  Field monitoring of pest populations  Use of biological agents  Chemical pesticides are last resort

28. Effects of IPM