1. Pest Control

2. Outline
Pests
Pesticides
Use and Types
Benefits
Problems
Alternatives
Reducing Exposure
Regulating Use
Organic Farming

3. PESTS AND PESTICIDES
Biological Pests - Organisms that reduce the availability, quality, or value of resources useful to humans.
Only about 100 species of organisms cause 90% of crop damage worldwide.
Insects are most frequent pests.
Make up three-fourths of all species.
Generalists
Compete effectively against specialized endemic species.

4. Pesticides
Pesticide - Chemical that kills (repels) pests.
Biocide - Kills wide range of organisms.
Herbicide - Kills plants.
Insecticide - Kills insects.
Fungicide - Kills fungi.
Acaricide - Kills mites, ticks, and spiders.
Nematicide - Kills nematodes.
Rodenticide - Kills rodents.
Avicide - Kills birds.

5. Conventional Pesticide Use

6. Early Pest Controls
Sumerians controlled insects with sulfur 5,000 years ago.
Chinese describe mercury and arsenic to control pests 2,500 years ago.
People have used organic compounds and biological controls for a long time.
Romans burned fields and rotated crops to reduce crop disease.

7. Current Pesticide Use
EPA estimates total pesticide use in the U.S. amounts to about 5.3 billion pounds annually.
Roughly half is chlorine and hypochlorites used for water purification.
Roughly 80% of all conventional pesticides applied in the U.S. are used in agriculture or food storage and shipping.
Homes and gardens account for only about 8% of total pesticide use in the U.S..

8. Pesticide Types
Inorganic Pesticides - Broad-spectrum, generally highly toxic, and essentially indestructible. (arsenic - copper)
Generally neurotoxins
Natural Organic Pesticides (Botanicals) - Generally plant extracts. (nicotine - phenols)
Fumigants - Small molecules that gasify easily and penetrate materials rapidly. (carbon tetrachloride - ethylene dibromide)

9. Pesticide Types
Chlorinated Hydrocarbons - Fast acting and highly toxic to sensitive organisms. (DDT - mothballs)
Inhibit nerve membrane ion transport and block nerve signal transmission.
Persistent - Tend to biomagnify.
Organophosphates - Extremely toxic to mammals, birds and fish. (Malathion)
Outgrowth of nerve-gas research.
Inhibit neurotransmitter enzyme.

10. Pesticide Types
Carbamates - Similar to organophosphates. (Sevin). - Extremely toxic to bees.
Biological Controls
Microbial agents
Bacteria
Parasitic wasps

11. PESTICIDE BENEFITS
Disease Control
Many insects serve as disease vectors.
Malaria, Yellow Fever
Crop Protection
Using pesticides, pre-harvest losses to diseases and pests are at 30%, with post-harvest losses at an additional 20-30%.
In general, farmers save an average of $3-$5 for every $1 spent on pesticides.

12. PESTICIDE PROBLEMS
Non-Target Species
Up to 90% of pesticides never reach intended target.
Pesticide Resistance and Pest Resurgence
Resistant members of a population survive pesticide treatment and produce more resistant offspring.
Pest Resurgence
Pesticide Treadmill

13. Creation of New Pests
Broadcast spraying is also likely to kill beneficial predators.
Under normal conditions many herbivorous pests are controlled by natural predators.
With advent of chemical pest controls, farmers have tended to abandon traditional methods of pest / pathogen control.
Mixed crops and rotation regimes.

14. Environmental Persistence and Mobility
Because chlorinated hydrocarbons (DDT) are so persistent, they tend to show up far from the point of dispersal.
Stored in fat bodies, and thus tend to bioaccumulate.
High levels detected in upper levels of food chain.
DDT banned from US for over twenty years, but high levels still detected in some areas.

15. Environmental Persistence and Mobility
Many persistent organic pollutants were banned globally in 2001.
Use was banned or restricted in developing countries for years, but between 1994 and 1996, the U.S. shipped more than 100,000 tons of DDT and POP’s annually.
Many returned to U.S. in agricultural products and migrating wildlife.

16. Human Health Problems
WHO estimates 25 million people suffer pesticide poisoning, and 20,000 die each year.
At least two-thirds resulting from occupational hazards in developing countries.
Long-term health effects difficult to conclusively document.
PCB’s have been linked to learning deficiencies in children.
Intake during mother’s pregnancy.

17. ALTERNATIVES TO PESTICIDE USE
Behavioral Changes
Crop Rotation
Mechanical Cultivation
Flooding Fields
Habitat Diversification
Growing in Pest-Free Zones
Adjusting Planting Times
Plant Mixed Polycultures

18. Alternatives to Pesticides
Biological Controls
Predatory / Herbivorous Insects
Genetics and Bioengineering
Hormones
Sex Attractants

19. Integrated Pest Management
Flexible, ecologically-based strategy that uses a combination of techniques applied at specific times aimed at specific pests.
Tries to minimize use of chemical controls and avoids broad spectrum controls.
Employs economic thresholds to determine the point at which potential economic damage justifies pest control expenditures.

20. REDUCING PESTICIDE EXPOSURE
Less than 10% of active pesticide ingredients have been subjected to a full battery of chronic health-effect tests.
Of the 321 pesticides screened, EPA reports 146 are probable human carcinogens.
Since 1972, only 40 pesticides have been banned.

21. Regulating Pesticides
Environmental Protection Agency (EPA), Food and Drug Administration (FDA) and Department of Agriculture (USDA) all share federal responsibility for regulating pesticides used in food production in the U.S..
EPA regulates sale and use, and sets tolerance levels.
FDA and USDA enforce pesticide use and tolerance levels set by EPA.

22. Regulating Pesticides
1999, EPA banned use of methyl parathion on all fruit and many vegetables, and limited the quantity of azinphos methyl that can be used on foods common in children’s diets.
Studies show children are more susceptible than adults to toxic pesticides because they are still developing and have less natural protection.

23. Is Organic the Answer ?
Numerous studies have shown organic, sustainable agriculture is more eco-friendly and leaves soil healthier than intensive, chemical-based mono-culture cropping.
Currently, less than 1% of all American farmland is devoted to organic growing, but market for such crops is growing.

24. Summary
Pests
Pesticides
Use and Types
Benefits
Problems
Alternatives
Reducing Exposure
Regulating Use
Organic Farming