1. Pesticides

2. Pests are any species that interferes with human welfare by: – competing with us for food – invading lawns and gardens – destroying building materials – Spreading disease – Invading ecosystems – Being a nuisance What are pests?

3. Naturally through predators, parasites and disease organisms – Ex: World’s 30,000 known species of spiders kill far more insects every year than humans do by using chemicals Controlling Pests

4. Chemicals used to kill or control populations of organisms that we consider undesirable. Common Types: – Insecticides – Herbicides – Fungicides – Rodenticides Pesticides

5. First generation – 1600’s – Natural chemicals borrowed from plants – Ex: Nicotine sulfate from tobacco leaves Pesticides

6. Second generation – 1930-1970s – Produced in a laboratory – Ex: DDT World’s most-used pesticide Hazardous to humans  strict control over its use Bioaccumulation Pesticides

7. Biopesticides – Since 1970 – Natural repellents, poisons and chemicals made by plants Pesticides

8. Broad: toxic to many pests including beneficial species – Ex: DDT, malathion, prathion Narrow (selective): effective against a narrowly defined group of organisms – Ex: Algicides, fungicides, avicides Broad vs. Narrow Spectrum

9. Advantages – Save human lives – Increase food supplies – Profitable – Work fast – Safe if used properly Disadvantages – Promote genetic resistance – Kill natural pest enemies – Pollute the environment – Can harm wildlife and people – Expensive for farmers Conventional Chemical Pesticides

10. Not effective in reducing U.S. crop losses – Despite a tenfold increase from 1942-1997 crop losses from insects doubles from 7% to 13% – Genetic resistance – Reduction of natural predators Effectiveness of Pesticides

11. Case Study: Bhopal, India

12. Integrated Pest Management (IPM) Uses information on the life cycles of pests and their interaction with the environment – Plan that is economical with few hazards Steps: – Set Action Threshold  at what level are pests a threat – Monitor and Identify Pests  not all pests require control, some are harmless or even beneficial – Prevention  plant pest resistant crops, rotate crops, etc. – Control  effective, less risky methods are used first

13. Increase use of biological, ecological and other alternative methods for controlling pests – Fool the pest – Provide homes for pest enemies – Implant genetic resistance – Bring in natural enemies – Use insect perfumes – Bring in the hormones – Reduce use of synthetic herbicides Alternative: Organics

14. Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) – Banned or severely restricted use of 64 active pesticides between 1972 and 2009 – Studies by NAS suggest that federals regulating pesticide use in the US are inadequate and poorly enforced Laws and Treaties

15. Genetically Modified Foods Involves moving genes from one species to another or designing gene sequences (gene splicing) Examples: – Disease resistant sweet potatoes in Africa – Nutrient rich golden rice Coming Soon: – Bananas with the Hepatitis vaccine – Cows resistant to Mad Cow Disease – Fruit and nut tries that mature faster

16. Genetically Modified Foods Pros Less water and fertilizer required Higher crop yields Less spoilage More resistant to disease, pests, and weather Can grow in saltier soils Cons Unknown ecological effects Less biodiversity Allergen risks May harm beneficial insects May cause mutations with unknown consequences May cause pesticide- resistant strains