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Bug Off!Bug-Off

  • Subject:
  • |
  • Grade(s): 6-8
  • |
  • Duration: Two class periods

Lesson Plan Sections

Objectives


Students will understand:
1. The process of scientific inquiry.
2. The interconnectedness of the environment.

Materials


For this lesson, you will need:
• Small shovel
• Soil
• Ants
• Large glass jars
• Rubber bands
• Cheese cloth
• Magnifying glass
• Tweezers
• Bread crumbs, bits of fruit, cereal pieces
• White vinegar
• Cayenne pepper
• Lemon juice
• Pens, pencils
• Paper
• Books and magazines about insects
• Computer with Internet access

Procedures


1. Locate an anthill and make sure the ants aren't a harmful species, such as fire ants. Dig up the anthill and the soil around it. You can usually find anthills during warm dry weather in grassy areas. Put the ants and soil in a glass jar and cover it with cheesecloth secured with a rubber band. You may wish to have two or three jars with ants. (Be sure to return the ants to their original habitat once students have completed the activity.) You may also purchase an ant farm from a biological supply house such as Carolina Biological Supply House (1-800-334-5551 orcarolina.com).
2. Display the ant jars in the classroom. Discuss with students the physical characteristics of insects; they are six-legged, have exoskeletons, and have bodies that are segmented.
3. Encourage students to talk about their feeling for insects. Do they find them useful in any way? Or are they just pests? Talk about what people do to prevent insects from encroaching on their personal space and food supply.
4. Bring up the subject of insecticides. Explain to students that during the 1950s there was widespread use of powerful insecticides. These toxic chemicals were used without regard to the environment and human health. Early environmentalists such as Rachel Carson, sounded the alarm that pesticides were harming more than insects. Pesticides were impacting the whole environment in a negative way. Now people are aware of the interconnectedness of ecosystems and attempt to use pesticides that are less harmful to the environment.
5. Ask students if they have ever heard the term organic. Allow them to discuss any prior knowledge they have about organic gardening and organically grown food.
6. Explain to students that they will conduct experiments with the ants to test three organic insect controls: cayenne pepper, white vinegar, and lemon juice.
7. Challenge students to make a hypothesis about which of the organic insect controls might work the best. Have students test their hypothesis by placing three cubes of bread in the ant jar (using tweezers) after sprinkling each cube with one of the above organic insect controls. Suggest that students examine the ants with the magnifying glass. Remind them to record all procedures and observations during the experiment. Have them record the differences between the ants' reaction to each piece of bread. For example, count the number of ants on each one.
8. Caution students to avoid getting the insect controls on themselves or their clothes. Students should wash their hands after the tests to make sure that the substances don't inadvertently get in their eyes.
9. Provide books and magazines about insects and organic farming for student research. If you have Internet access, you might also want to bookmark the insect-related Internet sites listed below. Students may be interested in researching how many organic farmers in the United States use organic insect controls compared to how many farmers do not. Have them come to a conclusion about why farmers do or don't practice organic farming. Some students may also wish to research and report about any chemical pesticides that are considered safe by the Environmental Protection Agency.
10. Ask student groups to incorporate their research with the results of their experiments and report their findings to the class. You may wish to divide the class into three groups so that each group can report on a substance. Allow class time for student presentations.

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Adaptations


Adaptation for older students:
Instead of having older students conduct tests on the effectiveness of the three organic insect controls listed above, have students devise their own experiments. However, students should still stay within the parameters of substances that are nontoxic to humans. Remind students to formulate a hypothesis and record their observations and results. Allow students time to report to the class about their experiments.

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Discussion Questions


1. What opinions do most people have about insects? Why do you think they feel this way?
2. Do you think that insects pose a threat to people, or are they just pests? Provide examples to support your opinion.
3. Debate the pros and cons of organic versus chemical insect controls.
4. Some insects are in danger of becoming extinct. Why might people want to protect these kinds of insects?
5. Why do you think some insects, such as lady bugs, are viewed in a positive way? Discuss other insects that you know of that are viewed positively.
6. Hypothesize the specific features insects have that help to make them so resilient to pest controls.

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Evaluation


You can evaluate your students on their experiments using the following three-point rubric:
  • Three points: Student observations and written records of the experiment are complete. They made a hypothesis about the effectiveness of the organic insect control and recorded the results of the experiment. Student group presentations were organized and all group members participated.
  • Two points: Student observations and written records of the experiment are complete. Student group presentations were organized and all group members participated.
  • One point: Student observations and written records of the experiment are incomplete. Student group presentations were organized but not all group members participated.

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Extensions


Unwanted Garden Guests
Encourage students to apply what they learned from their organic pesticide experiments to their home gardens. Suggest that they research more about organic farming and implement some of the ideas in their garden. Students can document their organic gardening techniques through captioned photographs, videotape, or annotated drawings.

A Who's Who Book of Bugs
Excite students to look at insects in a new way—as the stars of many stories, myths, and fables. Have students create a "who's who" of insects in literature from around the world. Challenge them to collect insect characters from as many different genres as they can. Some characters that you can use as examples include the African Anansi spider tales, the Aesop's fable of the cricket and the ants, and for older students, Gregor, the man who turns into a cockroach in Kafka's Metamorphosis. (NOTE: Spiders are not classified as insects but allow their inclusion for these purposes.) Ask students to consider why the author might have chosen the particular insect for the story.

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Suggested Readings


Alien Empire: An Exploration of the Lives of Insects
Christopher O'Toole. HarperCollins, 1995.
This book provides an in-depth look at the strange world of insects. You'll discover how they move and how their senses work, what they eat and how they keep from being eaten, and how they live with others of their own kind and how we can live with them. The book includes hundreds of incredible larger-than-life photographs that demonstrate the wonderful diversity of the insect world.

That Gunk on Your Car: A Unique Guide to Insects of North America
Mark E. Hostetler. Ten Speed Press, 1997.
It's a sad fact that, as you drive your car down the highway, your windshield often becomes spotted with the splats of dead insects. The author of this book covers 25 of the major groups of flying insects likely to encounter your car, with a section on the common attributes, the life cycles, the most common species, and things you can do with live representatives of each. Both the splat and a living insect from each group are depicted in colorful illustrations.

The Science Times Book of Insects
Nicholas Wade, editor. Lyons Press, 1998.
This is an entertaining and informative gathering of nearly 50 articles about insects from the Science Times section of the New York Times. Award-winning journalists write about everything from butterflies to cockroaches, from honeybees to mosquitoes.

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Links


Orkin Insect Zoo
Info for teachers and students on insects

The Cockroach Homepage
Everything you wanted to know about roaches

Insect Pests of Ornamental Plants
View slide show to read info and see photos of numerous insects; pests and beneficial insects are discussed

bugbios
Excellent site with lots of info and graphics on insects

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Vocabulary


Click on any of the vocabulary words below to hear them pronounced and used in a sentence.
speaker    adapt
Definition: To change so as to fit a new or specific use or situation.
Context: Insects often adapt to the pesticides used against them, resulting in future generations of insects that are no longer effected by the pesticide.
speaker    hygiene
Definition: Conditions or practices, such as cleanliness, conducive to health.
Context: Today people are conscientious about their personal hygiene, but in the past it was common for people to be unclean and covered in bugs.
speaker    organic
Definition: Obtained from living things; involving the use of food produced with the use of feed or fertilizer of plant or animal origin without the use of chemical fertilizers, growth stimulants, antibiotics, or pesticides.
Context: She uses organic pesticides such as cayenne pepper to keep insects away from her garden plants.
speaker    pesticide
Definition: An agent used to destroy pests.
Context: The pesticide DDT proved to be harmful to birds and animals as well as to the insects it was designed to destroy.
speaker    toxic
Definition: Poisonous.
Context: In the 1950s, the pesticides that were commonly in use were just as toxic to people as they were to the insects.

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Standards


This lesson plan may be used to address the academic standards listed below. These standards are drawn from Content Knowledge: A Compendium of Standards and Benchmarks for K-12 Education: 2nd Edition and have been provided courtesy of theMid-continent Research for Education and Learningin Aurora, Colorado.
 
Grade level: 6-8
Subject area: Life Science
Standard:
Understands how species depend on one another and on the environment for survival.
Benchmarks:
Knows that organisms can react to internal and environmental stimuli through behavioral response, which may be determined by heredity or from past experience.
 
Benchmark: Knows ways in which species interact and depend on one another in an ecosystem.
 
Benchmark: Knows relationships that exist among organisms in food chains and food webs.

Grade level: 6-8
Subject area: Life Science
Standard:
Understands the cycling of matter and flow of energy through the living environment.
Benchmarks:
Knows how energy is transferred through food webs in an ecosystem.

Grade level: 6-8
Subject area: Nature of Science
Standard:
Understands the nature of scientific inquiry.
Benchmarks:
Knows that there is no fixed procedure called "the scientific method," but that investigations involve systematic observations; carefully collected, relevant evidence; logical reasoning; and some imagination in developing hypotheses and explanations.

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Credit


Audrey Carangelo, freelance curriculum developer.

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