A caterpillar is the larval stage of a butterfly or moth. Physically, caterpillars look like worms, centipedes, coils, or larvae of other insects, but you can identify caterpillars based on the specific body parts they have. You can also identify certain caterpillar species based on their way of life. There are many sources of reference that can help you identify certain types of caterpillars.
Step
Part 1 of 2: Identifying Caterpillars in General
Step 1. Understand the basic anatomy of a caterpillar
Although physically the caterpillar looks like a worm, the caterpillar's body can be divided into three parts as when the caterpillar becomes an adult (becomes a butterfly):
- Head. The caterpillar's head consists of six pairs of single eyes divided into two clusters, and strong, sharp jaws that can tear leaves into small, edible pieces. At the bottom of the caterpillar's lips there is a spinneret that secretes silk. In addition to supporting the caterpillar's body when attached to the plant, the silk is also used as a cocoon material used by the caterpillar to metamorphose into a butterfly.
- Thorax. The thorax has 6 legs that are used to hold the caterpillar's body for food. After the caterpillar goes through the metamorphosis phase and turns into a butterfly, the legs (real legs) will still be there.
- Abdomen. Caterpillars have an abdomen that is longer than its abdomen when it has become a butterfly. In the middle of the abdomen there are eight temporary legs called prolegs. Caterpillars also have a pair of prolegs (known as anal prolegs) located behind their abdomen. These prolegs help it to climb.
- The caterpillar's entire body is filled with fine hairs (setae) which are the caterpillar's sense of touch. In certain species, the hairs appear so clear that the caterpillar looks hairy.
- In contrast to caterpillars, centipedes have one pair of legs for each body segment, with the number of body segments reaching 15 to 177 segments (the number of segments is always odd). Meanwhile, senggulung has two pairs of legs for each body segment, with the number of body segments reaching 10 to 180 segments. Therefore, the number of legs owned by senggulung is 40 to 75 pieces. Other insect larvae, such as beetle larvae, have only six legs.
Step 2. Identify the caterpillar's common habitat
Caterpillars are usually found on or around the plants they eat. However, some caterpillars, such as the larvae of the zebra swallowtail butterfly, use other caterpillars for food. Many species of caterpillars have body colors that resemble the plants they inhabit. With this body color, caterpillars can blend in with their environment and hide.
- Several other types of caterpillar species have body colors that resemble those of predatory animals (eg snakes). These species also often have markings that resemble eyes so that they appear larger. In addition to resembling predatory animals, some species also have colors that resemble inedible objects. For example, the larvae of the tiger swallowtail butterfly have a color similar to that of bird droppings.
- Some types of caterpillars have a bright body color. Many of the brightly colored caterpillars usually feed on poison on the plants they eat. The predators can also be poisoned if they eat the caterpillar. The monarch butterfly is known for its venom, both as a caterpillar and a butterfly.
- Unlike caterpillars, centipedes and senggulung can be found under rocks, logs, rotting wood, leaves, or other damp places.
Step 3. Pay attention to the way the caterpillar moves
The caterpillar moves slowly with a wriggling or wave-like motion, like an earthworm. The back segments of his body shrivel up, pushing blood into the front segments of his body so that the front segments lengthen. Its front legs grip the surface on its path as the muscles in its limbs contract so that the back segments of its body are carried forward.
In contrast to caterpillars, centipedes move very quickly using their legs
Step 4. Recognize the smell it produces
Some types of caterpillars, such as the zebra swallowtail caterpillar, have an osmeterial gland that is shaped like a "Y" in the neck. These glands produce a pungent odor that can repel predators.
Part 2 of 2: Recognizing Specific Caterpillar Species
Step 1. Notice the color pattern on the caterpillar's body
Regardless of their purpose to hide from their predators or simply to show that they have poison, most species of caterpillars can be distinguished by their distinct body color pattern. Some examples of caterpillar body color patterns that you can find are:
- The monarch butterfly caterpillar has a yellow body with black and white stripes.
- The forest tent caterpillar has a thick hairy body with black and blue colors. On his body there is also a white motif and is shaped like a keyhole. The motif is in every segment of his body, in the middle of his back.
- The eastern tent caterpillar also has a thick hairy body with black and blue colors, but the motif it has is in the form of an elongated white line. The motif is in the middle of his back.
- Gypsy moth caterpillars have thick hairy bodies, black in color with red and blue dots. These points are in the middle of the back.
- The tomato hornworm caterpillar has a pale green body with white and green markings and horn-like protrusions.
- Some types of snakes adjust their body color patterns according to the season. The caterpillar species Nemoria arizonaria adjusts its body color in spring so that it resembles the color of an oak flower. While in autumn, the color of his body resembles the color of the leaves of small trees. However, when metamorphosed (either in spring or autumn), the caterpillar will turn into a moth with a bright emerald green color.
Step 2. Watch what the caterpillar eats
Often you can identify a particular caterpillar species by the type of plant it lives in.
- The monarch butterfly caterpillar can be found on the underside of the leaves of the milkweed plant (in Indonesia, one of the species is the balloon flower plant). (Milkweed sap contains a toxin that makes the larvae and adults poisonous to predators.)
- Forest tent caterpillars can be found, among other things, on the leaves of ash, oak, aspen and sugar maple trees.
- Eastern tent caterpillars feed on the leaves of apple trees and cherry trees.
- The gypsy moth caterpillar feeds on leaves, especially the leaves of oaks and other hardwood trees, but sometimes they also eat the leaves of sugar maple trees.
- Tomato hornworm caterpillars can be found on the leaves and stems of tomato plants.
Step 3. Look for information about caterpillars in the field guide book
If you are not familiar with the caterpillar species in your area, or find a different species when you travel somewhere, you can find information about the species in the caterpillar field guide.
- For example, caterpillar field guides suitable for children are Peterson's First Guide to Caterpillars by Amy Wright and the Golden Guide to Butterflies and Moths by Robert T. Mitchell.
- For adults, suitable caterpillar field guides include Thomas J. Allen's Caterpillars in the Field and Garden and David J. Carter's A Field Guide to Caterpillars of Butterflies and Moths in Britain and Europe.
Step 4. Look up information about caterpillars on the internet
There are many reference guides on various caterpillar species available on the internet. You can access it via your home computer or gadget, as long as your device has an active internet connection.
- The Caterpillar Guide of Discover Life's IDnature series (https://www.discoverlife.org/mp/20q?guide=Caterpillars) can help you identify caterpillar species by determining the main color of the caterpillar's body, color patterns and motifs, number of feathers, and certain body parts.
- The Butterflies and Moths of North America website (https://www.butterfliesandmoths.org/identify) features a gallery of caterpillar photos that you can use to identify the caterpillar species you find. You can also ask the regional coordinator of the site to find out information about the caterpillars you find by uploading photos of the caterpillars. However, in order for you to do this, you must first register yourself on the site.
- Regional guidebooks such as Caterpillars of Pacific Northwest Forest and Woodlands and Caterpillars of Eastern Forests published by the North Padang Wildlife Research Center, United States Geological Survey have content structure that resembles that of their printed field guide. The Pacific Northwest guidebook provides information on caterpillar species based on their appearance, while the Eastern Forest guidebook groups caterpillar information by family.
- You can find additional referral sources, including mobile applications, by searching the internet.
Tips
- A magnifying glass is useful to help you identify certain characteristics of the caterpillar you find. In addition, to be able to use field guidebooks and guide sites more effectively, you will need to know some technical terms regarding caterpillar anatomy and habitat. These terms are more than just the terms listed in this article.
- If you are willing to take the time and be patient, you can raise any caterpillars you find until they metamorphose into butterflies. Currently only a few species of caterpillars, moths or butterflies are known. By providing a picture of the caterpillar and its adult form (butterfly or moth), you can simplify the process of identifying the caterpillar species.
