Try to Touch Me, I Dare You

What am I looking at?

This is the caterpillar of a cecropia moth, also called a robin moth because, in its adult stage, its color and size are similar to those of a robin. You can see the spiked balls that help it defend itself from predators (1) and its chewing mouthparts that it uses to eat the leaves of broad-leaved trees (2). The bright colors signal “beware” in the universal color code of nature. These warning colors are known as aposematic coloration; they can mean either “I am poisonous, venomous, or taste really bad” or “I’m bluffing.” In either case, it’s best to stay away!

In the case of this caterpillar, the warning is mostly a false alarm – although if disturbed the caterpillar can secrete a solution from its tubercles that can be mildly toxic or irritating, according to some sources. Click on the right arrow to see more views of this colorful caterpillar and of the striking red, brown, and white adult moth.

Biology in the background

The cecropia moth lives throughout North America, and its caterpillars feed on several different species of broad-leaved trees, including maples, birches, and cherries. The moths spend about five weeks as a caterpillar and then only about two weeks as a winged adult. They spend most of their time as caterpillars eating leaves and then pupate, wrapping themselves in a cocoon to transform into an adult. The adults have no functional mouthparts or digestive system and so do not eat.

Their only focus as an adult is to mate. The females release pheromones (reproductive chemicals) that can attract male moths from up to a mile (about 1.5 kilometers) away. In fact, individual male moths have been observed traveling up to seven miles (about 11 kilometers) to find a mate. Once it has mated, a female can lay up to 100 eggs. These moths are the largest in North America, and their cocoon is made of a form of silk, placing them in the family Saturniidae, also known as giant silk moths.

The caterpillars can grow up to 110 millimeters long, or a little larger than a human middle finger. The adult moths can have a wingspan of up to about 19 centimeters, or roughly the length of a whole human hand.

Technique

This image was created using macrophotography.