After completing this section students should be able to:


Terms: Epidermis, sclerite, tagma, labrum, labium, maxilla, mandible, antennae, ocelli, compound eye, femur (and other leg segments), haltare, direct flight muscles, ovipositor, elytra, hemielytra.

A. External Anatomy Structure.

     INSECTA, class in phylum ARTHROPODA.

        1. All arthropods have:

            a. Segmented bodies.

            b. Jointed appendages.

            c.) Bilateral symmetry.

            d. Chitinous exoskeleton.

        2. Insects also have:

            a. 3 body regions.

            b. 3 pair of legs.

            c. 1 pair of antennae.

        3. Characteristics of exoskeleton and endoskeleton.

            a. Exoskeleton provides:

               1) Support.
               2) Muscle attachment.
               3) Body covering (good protection).
               4) Water conservation.
               5) Growth restrictions (problem).
               6) Good mechanical advantage.
               7) Endoskeleton provides:

                    In comparison: ??

Parts of an Insect

        4. Insect body regions (tagma) and functions:

            a. Head, perception, food intake.

            b. Thorax, locomotion, food processing.

            c. Abdomen, reproduction, excretion.

        5. Head.

            a. Antennae.

            b. Eyes.

            c. Mouthparts (types).

            d. Chewing.

              1) Labrum.
              2) Mandibles.
              3) Maxillae.
              4) Labium.

            e. Chewing-Lapping.

            f. Siphoning.

            g. Piercing\Sucking.

            h. Sponging.

            i. Cutting\Lapping.

        6. Thorax.

            a. Legs.

            b. Wings.

            c. Indirect Flight Muscles.

            d. Direct Flight Muscles.

        7. Abdomen.

            a. Non-reproductive appendages.

            b. Cerci.

            c. Reproductive.

            d. Males

            e. Females


  1. Describe the differences between the exoskeleton and the endoskeleton.

  2. What are the major advantages of the exoskeleton? The disadvantages?

  3. List the different types of mouth parts found in insects and give an example of an insect group that has each type.

  4. What is a tagma?

  5. Describe the two basic types of flight muscles and explain how they differ.

  6. What is the function of the haltare? With what insect group is it associated?

  7. List the different types of legs found in insects and give one example of an insect group that has each type.

  8. How can some insects flap their wings faster than nerve impulses can fire?

  9. What is an ovipositor? In what ways can it be used?

  10. What is an aedaegus?

Return to Table of Contents

Go to Section IV - Insect Structures - Internal

<< back