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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.
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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
- 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.
- 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.
- 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
- 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
- How many pairs of wings does a dragonfly have
- Do the right and left wing of the pair beat together?
- 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?
SEQUENCING
YOUR THOUGHTS
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
Read more about this fascinating project at
UC Berkeley
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).
Special
Advisor to this Guide:
Peter Lissaman, Ph.D., Aerospace Engineering, University of
Southern California
Academic Advisors for this Guide:
Corrine Lowen, Science Department, Wayland Public Schools,
Wayland, MA
Suzanne Panico, Science Department, Fenway High School, Boston,
MA
Anne E. Jones, Science Department, Wayland Middle School,
Wayland, MA
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