Give Now  »

Noon Edition

Caterpillar vs. Plant

If you have kids, you've probably read The Very Hungry Caterpillar at least five thousand times. If you haven't had the pleasure, here's a brief plot summary. A caterpillar hatches from a small, white egg. Extremely hungry, the caterpillar proceeds to eat through several pieces of fruit, an assortment of junk food, and finally, to clear the palate, a nice green leaf. At the risk of ruining the ending, on the final page the caterpillar turns into a beautiful butterfly.

Good plot, great characterization, enticing illustrations. But it leaves out the most exciting part--plant-insect warfare. In the real world, some caterpillars and plants engage in a deadly struggle for survival. We're talking full-scale battle, involving chemical weapons no less.

Scientists have known for some time that many plants protect themselves from insect attacks by producing toxins that either ward off or kill insects when they attempt to have the plant for lunch. What scientists have only recently discovered, however, is that the common caterpillar is not without its own arsenal of chemical agents. According to recent studies, a caterpillar can sense when a plant is about to unleash its chemical weapons and counter act by producing anti-toxins to neutralize the plant's attack.

So far, caterpillars seem to have the upper hand. Although different plants produce a wide variety of toxins, many ultimately rely on two main chemicals. Since caterpillars have evolved to neutralize these chemicals, they are able to infest over one-hundred toxin-producing plant species across the United States.

Support For Indiana Public Media Comes From

About A Moment of Science