Pest Control 1 Pests Biological Pests any species

Pest Control 1

Pests Ø Biological Pests –any species that competes with us for food, invades lawns and gardens, destroys food, and spreads disease l ~100 species of organisms cause 90% of crop damage worldwide. 2

Pesticides Ø Natural or synthetic substance that kills or controls “pests” l l Herbicide - Kills plants. Insecticide - Kills insects. Fungicide - Kills fungi. Rodenticide - Kills rodents. 3

Current Pesticide Use Ø 5. 3 billion pounds used in US annually. l l Applied to food crops, cotton, fruit trees US accounts for 1/3 of worldwide pesticide usage 4

Pesticide Types Ø Inorganic Pesticides -highly toxic and bioaccumulates l Ø Arsenic, sulfur, copper, mercury, lead Chlorinated Hydrocarbons – synthetic organic compounds that affect nervous system of pests. l l Resistant to decomposition (biomagnify) Ex. DDT (banned) Organophosphates - Extremely toxic but short-lived Carbamates – affect nervous system of pests; water soluble, can contaminate groundwater Ø Fumigants- used to sterilize soil and prevent infestation of stored grain Ø Organic- derived from plants such as tobacco and chrysanthemum Ø Ø 5

Pesticide Benefits Ø Disease Control l Malaria, Yellow Fever Ø Crop Protection (profitable) l In general, farmers save an average of $3 -$5 for every $1 spent on pesticides. Ø Increase food supply l More food means food is less expensive 6

Pesticide Problems Ø Negative effects on non-target species l ~5% of a pesticide reaches a pest Ø Promotes genetic resistance • Pesticide treadmill Ø Creation of new pests l Kill beneficial predators that keep a number of pest populations under control 7

Pesticide Problems Continued Ø Accumulates in food chain l Stored in fat and thus tend to bioaccumulate. l Ø DDT banned from US for over twenty years, but high levels still detected in some areas • Persistent vs. nonpersistent Pesticide runoff l biomagnification Groundwater contamination Ø Threatens endangered species, pollinators, nitrogen fixing plants and human health Ø l l Acute and chronic effects 25 million people suffer pesticide poisoning, and 20, 000 die 8 each year.

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Pesticide Protection Laws in the U. S. Ø Government regulation has banned a number of harmful pesticides but some scientists call for strengthening pesticide laws. l EPA), USDA, FDA regulate the sales of pesticides under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). • EPA has only evaluated the health effects of 10% of the active ingredients of all pesticides 10

Alternatives To Pesticide Use Ø There are cultivation, biological, and ecological alternatives to conventional chemical pesticides. l Fool the pest through cultivation practices. • • • l l l Crop Rotation to disrupt life cycles Growing in Pest-Free Zones Adjusting Planting Times Mix plants (polyculture instead of monoculture) Intercropping Provide homes for the pest enemies. Implant genetic resistance. Use pheromones to lure pests into traps. Use hormones to disrupt life cycles. Mulch to control weeds 11

Alternatives to Pesticides Ø Biological Controls l Use of predators and parasites to regulate pest populations • • Preying mantis Lady bugs Wasps Bees 12

Integrated Pest Management (IPM) Ø An ecological approach to pest control uses a mix of cultivation and biological methods, and small amounts of selected chemical pesticides as a last resort. l Goal is to reduce crop damage to an economically tolerable level 13

What Can You Do? Reducing Exposures to Pesticides Ø Grow some of your own food Ø Buy organic food Ø Wash and scrub all fresh fruits and veggies Ø Eat less meat Ø Trim the fat from meat 14

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