1. Environmental Science
Chapter 9
Notes 3

2. Pest Control
Pests
Any organism that occurs where you don’t want it, or in large enough numbers to cause damage
Eat/destroy certain types of plants
Need to be controlled to keep up percent yields of crops

3. Pest Control Pesticides Substances that kill pests
Specifically – insects/small rodents
Types
Chlorinated hydrocarbons
Persistent…Example DDT
Persistent – doesn’t break down
Causes biological magnification
Organophosphates - degradable
Carbamates - degradable

4. Pest Control Drawbacks Health Concerns Pollution and Persistence
Chemical leaks
Can cause cancer
Pollution and Persistence
Don’t break down, accumulate in water and soil
Ex. Makes birds eggs so thin, they break when mama bird sits on them
Pesticide Resistance
Pests evolve resistance
New chemicals must be developed

5. Pest Control Biological Pest Control
Using living organisms or naturally produced chemicals to control pests
Breeding plants with natural defenses with those that don’t have them to have the defenses transfer over
Takes longer for resistance to evolve
Only hurts the pest it is trying to control

6. Pest Control Types of Biological pest control Predators Pathogens
Release natural predators to an area
Pathogens
Pathogens = disease causing organisms
Most common – Bacillus Thuringiensis
To control insect larvae and moths & butterflies
Disrupting Insect Breeding
Spread pheromones to confuse the males
X-rays sterilize male insects

7. Pest Control Plant Defense
Chemical compounds that repel pests and they are biodegradable
Can be extracted and used as pesticides
Physical barriers, for example tougher skin
Breeding plants with natural defenses

8. Pest Control Integrated Plant defense
Modern method of controlling pests on crops that seeks to reduce the number of pests, but does not completely eliminate the pest population
Uses a combination of:
Chemical pest controls
Mix of farming methods
Biological pest control

9. Genetic Engineering
Using modern technology to allow desirable traits in crop plants to be transferred through the direct manipulation of genes for those traits
A way to develop new foods
Taking the gene that carries the resistance to a particular pest and putting it into another type of plant
Continues to be heavily debated among scientists

10. Genetic Engineering Benefits
Scientists who support it liken it to cross-breeding
More precise and efficient, though
Biotechnologists say these foods are just as safe as regular foods
It can add nutrients, keep produce fresh longer, create more successful crops
Possibility? Creating crops that could grow in poor soil or poor water conditions?

11. Genetic Engineering Risks
Scientists that support this claim the foods are very different then the ones we currently consume
Safety concerns
Allergic reactions
Safety of the “foreign” genes in the plants
Religious/ethical concerns - inserting genes from foods they don’t eat into foods they do
Environmental - if introduced to the wild, they could thrive over the original plant and cause extinction