
Controlling Pests • Yesterday we talked about types of agriculture and sustainability • One thing that can greatly add sustainability is choosing appropriate pest management strategies • Pests can include… • Small animals • Insects • Disease • Bacteria
Types of pesticides • Pesticides differ in many ways • Chemistry • Effective time • Environmental persistence (how long they stay in the environment) • Effect on food webs • How the pesticide works (reproductive suppression, nervous system crash, etc.) • How fast they work • Application method
Types of pesticides • Biological • Living organisms used to control pests • Examples are bacteria, Bt (Bacillus thuringiensis), ladybugs, parasitic wasps, and viruses • Viruses still go in this category even though they aren’t living • CASE STUDY: • Bt is a soil bacteria that occurs naturally in caterpillar/butterfly guts • Acts as a toxin to specific groups of insects • Only insects that eat that crop will die • Carbamates • Also known as urethanes • Affect nervous system • 100 g of carbamate = 2,000 g of DDT • Water soluble, so they could get into surface or ground water sources • CASE STUDY: • Carbide plant in Bhopal, India leaked and exposed hundreds of thousands of people • 8,000 died • 200,000 with permanent injuries
Types of pesticides • Persistent Organic Compounds • POPs • Chlorinated hydrocarbons, such as DDT • Resistant to environmental degradation • Bioaccumulation • Can be found all over the world even if they weren’t used there • Organophosphates • EXTREMELY toxic but only stay in the environment for a short time • Example: malathion to control mosquitos with West Nile Virus • Fumigants • Sterilize soil and prevent pest infestation of stored grains • Inorganic • Arsenic, copper, lead, mercury • Highly toxic and accumulate • Organic/Natural • Natural poisons derived from plants • Examples: tobacco and chrysanthemum
Pros and cons Pros Cons Kill unwanted pests Increase food supply More food available = less expensive food Newer pesticides are safer and more specific Reduces labor costs Agriculture is more profitable Accumulate in food chains Pests develop resistance About $5 to $10 in damage to the environment for every $1 spent on pesticides Expensive to purchase/apply Runoff into water systems Inefficient – only 5% of pesticides reach the pest Can threaten other species that are endangered/pollinators
Integrated pest management • IPM uses a variety of methods • Goal is not to eradicate pests, just control them • Chemical pesticides are the last resort • IPM can include • Polyculture, intercropping, crop rotation • Planting pest-resistant crops • Using mulch, Bt, or natural predators to control weeds/pests • Releasing sterilized insects so they can’t reproduce • Regular monitoring • Development of GMOs that are more resistant
Relevant Laws • Federal Insecticide, Fungicide, and Rodenticide Control Act (FIFRA) • 1947 • Regulates manufacture/use of pesticides • Pesticides must be registered and approved with labels that describe use and disposal • Federal Environmental Pesticide Control Act • 1972 • Requires registration of all pesticides in US commerce • Food Quality Protection Act (FQPA) • 1996 • Protects children and infants in reference to pesticide residue in foods they may consume
Assignment for 4/10/14If you don’t finish in class, It becomes homework • You are a farmer in Warren County who is having a pest invasion, and you must decide if you will use pesticides or GMOs to control your pest issue. • Write a 2 paragraph essay that describes and explains your choice with the following information: • Your choice and 2 pros of your choice • How this plays into sustainability • What specific pesticide you would use or how you would genetically modify your plants • One possible con and how you would address it • What you think the public’s reaction would be to your choice