Caterpillars deliver biology’s old lessons in new ways

In Walter Goodman’s laboratory, Manduca sexta, a.k.a. the tobacco hornworm caterpillar, lives in the limelight.

The star of Walter Goodman’s show, Manduca sexta, chews on a leaf. If all goes well, elementary school students nationwide will be able to use the World Wide Web to observe the caterpillar’s life. Photo: Jeff Miller

Tune in to the life and times of Manduca sexta: http://manduca.entomology.wisc.edu/

Twenty-four hours a day, seven days a week, the caterpillar grows ever larger — and ever more interesting — under the steady, unblinking eye of a video camera. Soon, if all goes well, the caterpillar will become the star of biology class for elementary school students nationwide as they tune in through the World Wide Web to the life and times of Manduca sexta.

“This is serious fun for these kids, and that serious fun turns into serious learning,” says Walter Goodman, professor of entomology.

Like many other research scientists around the country, Goodman has labored to find ways to move primary school students beyond science texts to learn about biology first-hand. And now, through the Web and a growing collaboration with teachers from Wisconsin to Arizona, Goodman has found a way to capitalize on new, inexpensive technology to deliver lessons of life.

These virtual lessons in biology, says Goodman, can be combined with the opportunity for students to raise their own insects — from egg to moth — as well as a series of on-line lesson plans to introduce students to observation and experimentation, key aspects of the scientific method. Last year, more than 700 elementary school students in Wisconsin alone raised their own caterpillars, charting growth, food consumption, color changes and behavior.

Growing quickly from a tiny worm the size of a grain of rice to an insect of almost Herculean proportions – about the size of an index finger – the tobacco hornworm, says Goodman, is an ideal prism for viewing the lessons of biology.

Walter Goodman

Because it develops quickly as it cycles through the several stages of caterpillarhood known as instars, students can see development first hand and, ultimately, view the rarely observed process of metamorphosis as the caterpillar changes into an adult moth. But it is during its life as a caterpillar that the tobacco hornworm serves up a host of biology lessons that children can readily absorb.

“They have a heart, a complex nervous system, a gut – everything that you have” as well as an almost transparent cuticle that is like a window to the caterpillar’s internal organs, Goodman says. “It helps people who’ve never really looked closely at insects before to understand what they’re all about.”

Now, with the help of the Center for Biology Education through the Science Education Scholars Program, students from the UW–Madison School of Education, and Madison public school teachers, Goodman is bringing his vision to the Web.

In addition to basic information on the caterpillar’s life history, lesson plans, and information on how to raise your own Manduca sexta, Goodman’s web site has a caterpillar under 24-hour video surveillance, meaning that students miss nothing as the caterpillar grows and undergoes metamorphosis.

Such a steady watch, says Goodman, may even contribute to science a better understanding of the insect’s life cycle. For example, to accommodate pupation, when the caterpillar changes from worm to moth, it burrows underground and makes a protective cell where it undergoes metamorphosis.

“How the adult moth digs its way out of the soil remains a mystery,” says Goodman, a veteran of 25 years of work with the moth.

By bringing the insect to the web, Goodman and the students and teachers who work with him hope to bring a new and more powerful way of learning about the world to more students.

“With the live video camera, the kids aren’t looking at a picture that was taken five years ago,” says Sean Ruppert, a UW–Madison School of Education student who, with fellow UW–Madison student Tess Bashaw, is helping develop the web site. “It gives them a real-life feel.”

And that cyber reality, argues Goodman, is important as some teachers are either too squeamish or lack the resources to encourage their students to raise dozens of caterpillars in the classroom. Says Goodman: “Not all teachers like insects. The Web is a way to get around that and still deliver the message.”