Pesticides

Pesticides

What are Pesticides?

Pesticide: Any substance used for the purpose of destroying or controlling pests. Used in agriculture to protect crop plants

Types of pesticides:

Pesticide What does it KillInsecticide InsectsHerbicide Plants (weeds)Fungicide FungusAlgicide Algae

Rodenticide Rodents

What are pesticides made from?

Components:

What are pesticides made from?

Components:

How do pesticides workInsects: Most work through poisoning the insect

Herbicides: Absorbs through the membranes

Fungicides: Enters fungus through absorption

Chemical Pesticides

Chemical Pesticides are Grouped into Chemical FamiliesOrganochlorines: Attack the nervous system of insectsOrganophosphates: Replaced organochlorides. Also a neurological pesticide. Used in nerve gases. Effective herbicide.Carbamates: Replaced organophosphatesprevents nerve impulses from being transmitted causing paralysis

Chemical Pesticides

Chemical Pesticides are Grouped into Chemical FamiliesPyrethroid pesticide: Comes from the chrysanthemum. Attacks nervous systemSulfonylurea Pesticides: Kills plants by inhibiting enzymes

Biopesticides

Biopesticide: Bio = living Pesticide = killing substanceBiopesticides are substances from natural sources that are used to destroy or control organisms Examples:Canola oil, baking soda

Three Classes of BiopesticidesMicrobial Pesticides: Microorganisms that are used to control pests. Can include beneficial bacteria, viruses, fungus and protozoans

Plant-Incorporated-Protectants: Adding genetic material to plants that allow them to make the pesticide chemicals found in the beneficial organisms

Biochemical Pesticides: Using chemicals produced by organisms to reduce pest populations.

eg. Releasing scent chemicals to lure pests into a trap

Cost of Pesticides

HealthAcute (immediately) Illnesses caused by pesticides: -Skin and eye irritation-Nervous system problems-Infertility by mimic reproductive hormones Chronic (long term) Illnesses caused by pesticides:-Cancer (Leukemia)- Birth defects- Neurological Disorders (autism)

Cost of Pesticides

Pesticide Drift: Occurs when pesticides are blown into unintended location by wind. Over 90% of the pesticides we apply does not reach its target pest species.

Problems with PesticidesWater Pollution: Many pesticides are persistent organic pollutants. These increase in concentration as they move up the food chain. Results in nerve damage in aquatic organisms.Biodiversity: Loss of higher trophic species due to bioaccumulation.Pollinator Decline: Pollinating insects such as bees spend a lot of time in crops. When a pesticide is sprayed for insects It kills the pollinators.

Alternatives to Pesticides

1) Using carnivorous insects to eat crop eating pest insects

2) Using genetically modified foods3) Crop rotation. Planting corn in a wheat field

which is contaminated with a pest that attacks wheat but not corn.

Assignment

Questions 1-6