Success Criteria: You can describe the benefits and risks of using pesticides.
Handouts:
What can we do about insects that might eat our crops or be harmful to humans?
We could eat them!
Of course that would only take care of a few of them. Farmers could us pesticides that could eliminate most of the pests at once.
This would increase crops yields and protect us from harmful insects such as mosquitoes that spread diseases. However, there are environmental costs to consider.
- Non-target species:
- pesticides could also kill beneficial insects like bees and spiders.
- Bioaccumulation and bioamplification:
- organisms higher on the food chain, such as fish and birds can be seriously affected by accumulated pesticides.
- Pesticide resistance:
- some pests can develop resistance making the pesticides less effective.
Make sure you understand and can explain the three situations listed above. DDT is chemical that was once used as a pesticide. The full name is dichlorodiphenyltrichloroethane (You will not be asked to to spell it!) It causes toxic effects to birds through the process of bioaccumulation and bioamplification.
To avoid these environmental costs, some farms do not use synthetic pesticides. They end up with lower crop yields and must offset it with higher costs.
This table shows a price comparison of organic vs. conventional foods. It costs a lot more to eat organic.
Homework: complete your assignment and hand it in tomorrow.
No comments:
Post a Comment