Examine insects' ability to adapt to their environment

 

Overview: CNN Student News correspondent Michael McManus talks with Dr. Natalia Vandenberg, an entomologist at the Smithsonian Museum of Natural History. Investigate the stages of gradual and complete metamorphosis. Have students identify local habitats and insects in those habitats and determine how insects "make a living" in the given habitat.

Curriculum connections: Biology, Life Science

Objectives
Students will be able to:

Standards National Science Education Standards
Life science, Content standard C, grades nine –12
High school students should know that living organisms have the capacity to produce populations of infinite size, but environments and resources are finite. This fundamental tension has profound effects on the interactions between organisms.

National Science Education Standards
Life science, Content standard C, grades nine –12
High school students should know that organisms both cooperate and compete in ecosystems. The interrelationships and interdependencies of these organisms may generate ecosystems that are stable for hundreds or thousands of years.

Materials
CNN Student News story, "Geographic distribution and habitats: Ladybugs"
Internet access

Suggested time
Article and questions only: 30 minutes
Full lesson plan: Two to three classroom periods

Procedure
1. Have students read the CNN Student News story, "Geographic distribution and habitats: Ladybugs," and ask the following:

2. Discuss how insects grow from an egg to an adult beetle, butterfly, grasshopper, etc. Ask: What are some terms used to discuss insect development? Introduce the term metamorphosis. Group students. Refer students to the Web sites below and their textbooks to investigate complete and gradual metamorphosis. As a class, create a list of habitats near your school, such as a field, pond, forest, stream, marsh or shore. Assign each group a different habitat from the list. Have each group conduct further research and identify the following about the habitat:

Point out that many insects that go through complete metamorphosis, though not all, utilize different food resources and live in slightly different habitats. Ask: What are some advantages of metamorphosis for insects in various habitats.

3. Have each student select an insect that lives in his/her region. Refer students to the first Web site below for a dichotomous key to use to identify their insects. Direct each student to make a drawing that shows the insect's characteristics. Direct each student to identify how the insect's characteristics influence its survival in different types of environments. Have each student determine the insect's food sources and possible economic importance (i.e., agricultural or ecological contributions) in each of the different types of environments. Have students share their findings.

4. Write the term "environment" on the board. Brainstorm with students components that an environment may include. Have a student write the list on the board. Then, ask: Do you think all of these components are important to an environment? Explain.

5. Have students define the following terms: "populations," "communities," and "ecosystems." Ask: From the list of components of an environment listed on the board, which components might be grouped under populations? Under communities? Under ecosystems? Are there any components that should be added to or deleted from the list? Discuss. How do these components affect characteristics of the insects in each population? Community? Ecosystem? Discuss.

Assessment
Have students write essays answering the following questions: What characteristics do insects use to facilitate their adaptation in different environments (such as moving from a very humid region to a cold region)? How do the adaptations affect their survival? Have students share their essays with the class.