Environmental Science
Name: ______________________________
Food and Agriculture
Goal: The student will explain the benefits and environmental impacts of pesticide use and explain what is
involved in integrated pest management.
Vocabulary:
1. Pesticide
2. Biological pest control
Chapter 9.2 continued: Crops and Soil
Pest Control
• In North America, _______% of all crops are destroyed by insects; tropical climates enough greater damage;
Kenya lost 25% of their crops from _______________________; worldwide, 33% of the world’s potential food
harvest is destroyed
• __________________ plants have more protections from pests than do crop plants; wild plants are scattered,
therefore, harder to find, have evolved defenses and have pest __________________________living in or around
them; crops plants are all in one location, a one-stop food source
Pesticides
• Over the last 50 years, many new _________________________ pesticides have been developed and farmers
have begun to rely on them to protect their crops; used to kill insects, weeds and other crop ________________
• Unfortunately, the new pesticides affect a lot _______________ than just the pests that they were designed to kill
• They can also harm _______________________, wildlife and beneficial plants and insects
Pesticide Resistance
 If large amounts of pesticides are used _____________________, over time, the pest problem will become worse.
• Pest populations ________________________ to become resistant and survive through exposure to that particular
pesticide; How? Some of the insects have a _________________________ that protects them from a pesticide;
they go on to reproduce, passing on that resistance gene to their offspring
 More than ________________ species of insects have developed resistance to pesticides since the 1940’s
Human Health Concerns
• Many _____________________________ can cause people to get sick
• Ex: California has seen an increase in ______________________ rates among children in areas which grow fruits
and vegetables with __________________ pesticide use; people applying the pesticides have to follow safety
guidelines to protect themselves from contact with these chemicals
• Workers in ___________________________ factories may become ill, as well as the people living near these
factories, from accidental chemical leaks
Pollution and Persistence
• Pesticides can become problematic for humans and wildlife because they are ________________________(don’t
break down ________________________ into harmless substances when they enter the environment), they
accumulate in the water and soil
• Ex: DDT – used in the 1940”s to kill ______________________________(malaria, lice that spread typhus);
DDT is very persistent, gradually accumulates in bodies of water, absorbed by fish, and then eaten by birds;
resulted in increased levels of DDT in bodies; __________________ were so thin they broke when sat on
(penguins, pelicans, peregrine falcons, eagles); many became endangered
• DDT _____________________________ in U.S.; but continues to remain in the environment
Biological Pest Control
• Because resistance _____________________ so rapidly, farmers and pest-control companies are using fewer
pesticides and practicing some form of pest management
• Turning to ___________________________pest control (using living organisms or naturally produced chemicals
•
to control pests); every pests has enemies in the wild and those enemies can be used to __________________ pest
populations (ex: In India (mid-1800’s), American prickly pear cactus had been introduced into India to feed
insects that are used to make a valuable ______________dye; Cactus had no natural enemies, grew and spread.
Plants were finally controlled by the introduction of an American beetle that eats cactus
Generally, do no ____________________anything but the particular pest it is designed to control, resistance takes
longer to evolve
Pathogens
• Releasing a natural ________________________ or parasite is one method of biological control
• _________________________ (organisms causing disease) is another method
• Ex: Bacillus thuringensis (bacterium) kills larvae (caterpillars of moths and butterflies)
Lesson Reflection:
Compare the benefits and environmental impact of pesticide use.
Assessment:
1. Define the term pest.
2. Describe how biological pest control is part of integrated pest management.
Active Reading: Crops and Soil
Lesson Extension (Technology/Application/Connection to Real World):
Learn 360 – The Exterminator (45 min)