Winging It Make a Wind Tunnel On the Wings of Insects Quiz

In many insect species the final molt gives rise to an adult body form that includes functional wings. These structures allow insects to fly, like birds, bats and some fishes. Unlike the bird wing, but like the wing of the bat, the insect wing consists of a thin membrane. As with all wings, flapping provides the lift (vertical force) and thrust (horizontal force) to fly.

There are many different types of wings and beating patterns among the orders of insects. Some have only one pair of wings, others two. These are so dramatic that they are used to distinguish insect orders

A flipbook is an ideal device for tricking your visual perception. When images are changed at a fast enough rate, the brain does not see the separate images but blends then together to give the illusion of a smooth motion. This is the basis of the movie film, which consists of thousands of still pictures, each projected for a fraction of a second. In this activity, you will assemble a flipbook whose frames illustrate the movements of the paired wings of a dragonfly.

OBJECTIVE
This activity page will offer background tin insect flight, the opportunity to integrate sensory illusions with life science, and an opportunity to observe the coordinated flapping of the insect wing.

MATERIALS

• Two printouts of the 12-frame dragonfly sequence.
• Scissors
• Paper fastener (trombone or spring clip type)
PROCEDURE

PART 1 - Making the Book

1. Obtain three printouts of the 12-frame animation. Cut out each of the 12 frames that form these three complete motions, making 36 frames in all.
2. Make a stack using all three sets of frames with the one set above the other. The lowest number, #1 should be at the top.
3. Off-set the 36 frames slightly, with the bottom edge of the bottom-most frame extending out further than the top-most frame (see diagram). Use a paper clip to clasp together the 36-frame flipbook.

PROCEDURE

PART 2 - Operation

1. Hold the book in your right hand and slowly flip the frames from the top to the bottom using your left thumb. What do you see?
QUESTIONS

1. How many pairs of wings does a dragonfly have
2. Do the right and left wing of the pair beat together?
3. Do both pairs have an upstroke that occurs at the same time? Explain.

CRITICAL ANALYSIS

Why were three stacks of frames used instead of one?

Suppose the frames were placed in the reverse sequence with #1 at the top. What would you see now?

EXTENSIONS

Model Wings

Work in a team. Research the types of wings found in butterflies (Order Lepidoptera, "scale-winged"), grasshoppers (Order Orthoptera. "straight-winged"), beetles (Order Coleoptera, "sheath-winged") and flies (Order Diptera, "two-winged"). Find out what their names mean. Using a variety of art materials construct models that demonstrate the obvious differences in the anatomy and wing structure of these flying insects.

WEB CONNECTION

Key to Insect Orders

Micromechanical Flying Insect Project

The Development of Insect Flight
Take a tour of this interactive exhibit at the Hooper Virtual Paleontological Museum

The activities in this guide were contributed by Michael DiSpezio, a Massachusetts-based science writer and author of "Critical Thinking Puzzles" and "Awesome Experiments in Light & Sound" (Sterling Publishing Co., NY).