Goal of Pesticides

• Control pest organisms to reduce crop damage and increase crop yield

Ideal pesticide

• Kill only target pest

• Harm no other species

• Breakdown into something harmless

• Not cause genetic resistance

• Cost-effective

Pesticides can be:

• Broad-spectrum

• Narrow spectrum

• Vary in persistence

Types of pesticides

• Insecticides: insect killers

• Herbicides : weed killers

• Fungicides : fungus killers

• Nematocides : roundworm killers

• Rodenticides : rat and mouse killers

5 major pests in the United States

• Grasshopper

  • Destroys crops in western U.S.

• European red mite

  • Destroy deciduous fruit trees - apple, pear, plum

• Boll weevil

  • Destroys cotton fields in the South

• Pink boll worm

  • Destroys cotton farms in the South

• Gypsy moth

  • Caterpillar destroys hard wood trees in the East

History of Pesticides

• 500 B.C - sulfur

• 1400s - arsenic, lead, mercury

• 1600s - tobacco leaves

• 1800s - pyrthrum and rotenone

• 1939 - DDT

DDT

• Dichlorosdiphenytrichloroethane

• Pros

  • Controlled pests

  • Broad-spectrum

  • Inexpensive

  • Not water-soluble

  • Crop yield increased

  • Controlled malaria

• Cons

  • Non-target creatures killed

    • Birds

    • Fish

• Banned in 1972

Regulation

• FIFRA

  • Federal Insecticide, Fungicide, and Rodenticide

  • Amended in 1972

  • New and Old products

  • No more than 1 cancer per million people for certain pesticide over a lifetime

  • Requires EPA approval for the use of pesticides

• 1996 Food Quality Protection Act

  • Human health

  • Amount that can remain on crop when eaten

Advantages of Pesticides

• Saves lives

• Prevents diseases

  • Malaria

  • Bubonic plague

  • Typhus

  • Sleeping sickness

• Increase food supply

• Lowers food waste

• Works better and faster than alternatives

• Minimal health risks

Disadvantages of Pesticides

• Pesticide mobility

  • Pesticides are carried out by the wind and water runoff

    • Disrupts food webs that are far away

• Genetic resistance

• Causes human health problems

Other ways to control pests

• Cultivation practices

• Genetic Engineering (GMO)

• Biological pest control

  • Natural predators

  • Parasites

  • Bacteria

• Incest birth control

• Spraying insects with hot water

  • Works well on cotton, alfalfa, and potatoes

• IPM - integrated pest management

  • Limited use of pesticides and other practices

IPM - integrated pest management

• Ecosystem based strategy that focuses on long term management of pests

• Cultivation

  • Fool the pest through cultivation practices

    • Ex: intercropping - plant a crop that attracts the pest to protect the cash crop

• Biological

  • Attract the pest’s predators

  • Add viruses that attach to specific insect’s larvae

  • Implant genetic resistance

  • Use pheromones to lure pests into traps

• Physical

  • Put a net around the crop

  • Vacuum harmful bugs

• Disadvantages

  • Requires expert knowledge

  • Methods applied in one area might not apply in another

  • Initial cost is higher