Pest control
1 / 16

Pest Control - PowerPoint PPT Presentation

  • Uploaded on

Pest Control. Chapter 12 APES 2008. What are pesticides?. Chemicals that kill pests Biocides- kill wide range of pests Herbicides- kill plants Insecticides- kill insects Fungicides- kill fungi. History of Pesticides. Every culture has used pesticides

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Pest Control' - letitia

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Pest control l.jpg

Pest Control

Chapter 12 APES


What are pesticides l.jpg
What are pesticides?

  • Chemicals that kill pests

    • Biocides- kill wide range of pests

    • Herbicides- kill plants

    • Insecticides- kill insects

    • Fungicides- kill fungi

History of pesticides l.jpg
History of Pesticides

  • Every culture has used pesticides

  • Modern era of pesticides began in 1934 with development of DDT (Dichloro-Diphenyl-Trichloroethane)

  • Used in WWII to control parasites & tropical disease

  • Was cheap, stable, soluble in oil, easily spread over wide areas.

  • High toxicity for target organisms- kills 90% of target organisms in single application

  • It was the “magic bullet”- the answer to our prayers… or was it?

History of pesticides4 l.jpg
History of Pesticides

  • Indiscriminate & excessive use of pesticides has caused

    • Damage to ecosystems

    • Harm to human health

    • Creation of “superbugs”

  • ¾ of all pesticides are used in Most Developed Countries (MDC) but rates in LDC are on the rise by 7-8%.

  • DDT was banned in US in the 1970’s. We can now only use it in emergencies.

  • DDT is still used in many other countries- especially for control of mosquitoes.

Children playing in DDT clouds at beach.

History of pesticides classified based on chemical structure l.jpg
History of Pesticidesclassified based on chemical structure

1st stage included Inorganic Pesticides

  • Arsenic, copper, lead, mercury

  • Highly toxic & indestructable

Arsenic poisoning from infected water sources in Bangladesh

History of pesticides6 l.jpg
History of Pesticides

2nd stage included petroleum based sprays and natural organic pesticides

  • Nicotine, rotenone

  • Botanicals

  • From plants

History of pesticides7 l.jpg
History of Pesticides

3rdstage included chlorinated hydrocarbons

  • DDT, chlordane, aldrin, dieldrin, toxaphene

  • Block nerve signals

  • Fast & toxic, carcinogenic

  • Biomagnify- stay in ecosystem

  • Dieldrin 50X as toxic to people as DDT

  • Toxaphene kills goldfish at 5 ppb- one of the highest toxicities for any compound

History of pesticides8 l.jpg
History of Pesticides

4th stage: Biological controls-

  • using live organisms or their toxins instead of pesticides

  • Bacillus thuingiensis (Bt)- kills beetles, caterpillars by destroying their digestive tract

  • Parasitic wasps

  • Ladybugs eat aphids

  • Viruses

Alternatives to pesticides l.jpg
Alternatives to Pesticides

  • Biological controls- natural predator

    • Bacillus thuringiensis (Bt)- kills beetles & caterpillars

    • Ladybugs, praying mantises, wasps

    • Ducks & geese in fields will eat insects & weed seed.

    • Planting garlic or marigolds can deter pests.

    • Release of artificial hormones can disrupt life cycles (sex phermones)

Alternatives to pesticides10 l.jpg
Alternatives to Pesticides

  • Integrated Pest Management (IPM)- use a combination of methods, including biological control, chemical pesticides, and methods of crop planting.

  • Vacuuming bugs off crops

  • Move away from monoculture- grow several crops to confuse the pest.

  • No till or low till agriculture- helps natural enemies to build up in the soil

  • Trap crops- mature before rest of field to attract pests, then sprayed heavily, destroy trap crop to prevent spread to people or “real” crop.

Ipm continued l.jpg
IPM continued

  • Crop rotation keeps pest population low.

    • Using cover crops keeps weeds down

    • Provide habitat for natural predators (plant trees along edge of farm for birds which will eat bugs & provide windbreak which prevents erosion)

Benefits of pesticides l.jpg
Benefits of Pesticides

  • Reduce disease transmission by insect vectors (DDT sprayed to kill mosquitoes & prevent malaria, when stopped in 1964, malaria reappeared immediately)

    • Which is more important? Protecting people or the environment?

    • If you had to choose between contracting masses of worms that will make you go blind before the age of 30 or a small chance of cancer due to pesticide exposure it you live to 50 or 60, which would you choose?

  • Reduce crop losses by two-thirds.

    • Farmers save $3-$5 for every $1 they spend on pesticides.

    • Lowers costs and increases crop quality

Problems with pesticides l.jpg
Problems with Pesticides

  • Non-target organisms affected

    • Potato aphid spraying killed migrating robins

    • Insecticide spraying in CA killed salmon

    • Honeybees disappearing

  • Resistant individuals will develop due to natural selection

  • Pesticide is killing off natural predators that help control bad populations

  • Limited useful lifespan- can move far from original application spot (next slide)

  • Persistant organic pollutants (POP’s) are very long lasting and dangerous. Banned in most countries but persistent in soil & water

  • Affect Human Health

    • Acute- poisoning & illness

    • Chronic- cancer, birth defects, degenerative diseases

Pest resurgence leads to the use of higher doses or more toxic chemical use

The grasshopper effect l.jpg
The Grasshopper Effect

  • Many chemicals like chlorinated hydrocarbons evaporate from water & soil in warm areas & condense & precipitate in colder regions.

  • This happens over & over, “hopping” northward until it collects in polar regions.

  • Affecting top predators (polar bears, whales, & humans)

  • Some carcasses have to be treated as toxic waste they are so “infected” with pesticide.

  • Be familiar with “The Dirty Dozen”- from toxicity handout

About human health l.jpg
About Human Health…

  • Yaqui children in Mexico tested…

    • Foothills children age 4-5 not exposed to much pesticide

    • Valley children age 4-5 repeatedly exposed

Who regulates pesticide usage l.jpg
Who regulates pesticide usage?

  • Environmental Protection Agency (EPA)

    • Regulates sale & usage under Federal Insecticide, Fungicide, & Rodenticide Act (FIFRA) which mandates the “registration” of all pesticide products.

    • Determines which pesticides are safe to use for humans & environment

    • Sets tolerance levels for residues that may remain in or on foods marked in U.S. This falls under the Federal Food, Drug, and Cosmetic Act (FFDCA).

  • Department of Agriculture (USDA) & Food & Drug Administration (FDA) enforce pesticide use & tolerance limits set by EPA. Can seize & destroy food shipments that violate.