Is a Caterpillar an Insect? (Answered)

Caterpillars are not only unusual-looking, but they have the ability to transform into stunning butterflies and moths. They are considered both beneficial, as well as an agricultural pest, depending on the species of caterpillar. While caterpillars are a rather common sight, their appearance can confuse people who wonder “is a caterpillar an insect or is it a worm?”

Is A Caterpillar An Insect?

Caterpillar on a plant
Caterpillar on a plant by Pam Carter from Pixabay

Yes, caterpillars are insects. Caterpillars have 6 proper legs and up to 5 pairs of prolegs, which are stumpy and contain little hook-like feet at the end. There are over 20,000 species of caterpillars found throughout the world, and these interesting creatures are the immature form of moths and butterflies.

Are Caterpillars Insects Or Arthropods?

Caterpillars are both an insect and an arthropod. Arthropods are invertebrate animals in the Arthropoda category, which includes insects, arachnids, crustaceans, and myriapods. What this means is that any organism that is considered an insect is also an arthropod.

Are Caterpillars Herbivores?

Caterpillar eating a leaf
Caterpillar eating a leaf by 631372 from Pixabay

Herbivores are organisms that mainly consume plants, and most caterpillars are classified as herbivores. They typically consume leaves, though some caterpillar species will also eat fungi, other caterpillars, and dead animal matter.

There are, however, some caterpillars that consume fabric. The clothes moth caterpillar feast on fabric, such as what is found in your closest, and can cause extensive damage and can be difficult to get rid of.

Some caterpillars also prefer to feast on certain types of plants over others. The hornworm, for example, is a common caterpillar that can wreak havoc on various crops. These insects prefer to dine on tomatoes and other plants in the nightshade (Solanaceae) family, including tobacco, peppers, potatoes, and eggplants.

Are Worms Insects?

Earthworm on a dried leaf
Image by Eukalyptus from Pixabay

No, worms are not insects. Unlike caterpillars, worms are not complex creatures. They are, instead, invertebrates and do not contain an exoskeleton, which is a requirement to be labeled an insect. Worms are also not caterpillars and are actually separate types of creatures. Caterpillars are the larva stage of butterflies and moths, and worms are simply in their final adult stage.

What Insects Are Not Insects?

Along with worms, there are other animals that most people assume are insects, but that couldn’t be further from the truth. The most famous of these are spiders, which are in a classification known as arachnids that also includes mites, scorpions, and ticks.

While both insects and spiders are invertebrates, spiders are not considered insects because they have more than 6 legs. In order to be considered an insect, they would need to have 6 legs or 3 pairs of legs. Spiders, however, have 8 legs or 4 pairs of legs. They also only have 2 main body parts, instead of the 3 that are required to be classified as an insect.

Other insects that are actually not insects include centipedes and millipedes, both of which are arthropods.

Are Moths And Butterflies Insects?

Moths are insects during immature stage
Image by Schwoaze from Pixabay

Yes, like their immature stage the caterpillar, moths, and butterflies are insects. Like other insects, moths and butterflies have 3 main body parts and 6 legs, as well as an exoskeleton. They are the adult stage or final stage in the caterpillar’s life cycle.

What Is The Difference Between Moths And Butterflies?

Gulf Fritillary
Gulf fritillary butterfly | image by Renee Grayson via Flickr | CC BY 2.0

Both moths and butterflies are in the same order, known as Lepidoptera, but they have various behavioral and physical differences, which makes them two distinctive insect types. For example, moths typically fold their wings in a tent-like manner that hides their abdomen, while butterflies will fold their wings over their backs vertically. Furthermore, moths are typically smaller than butterflies, and butterflies are generally more colorful.

Do Caterpillars Lose Their Legs?

The caterpillar has multiple sets of legs. They keep their 6 main legs, but typically lose their other “false” or prolegs as they get older and more developed. When the caterpillar turns into a cocoon to become a butterfly or moth, it will develop new legs for its new body.

What Is The Life Cycle Of A Caterpillar?

Pupa of butterflies
Pupa of butterflies by GLady from Pixabay

Caterpillars are not the first part of the life cycle, nor is it the last. Moths and butterflies go through 4 different life stages. The first is the egg, which will then develop into the caterpillar (also known as a larva), followed by the pupa stage (chrysalis or cocoon), and then the final adult stage.

How Long Does It Take For A Caterpillar To Become a Butterfly Or Moth?

The exact time frame for a caterpillar to turn into a butterfly or moth varies depending on several factors, including the species of insect. Some species take a week or less to undergo metamorphosis, while others take an average of 3 weeks. There are, however, some butterflies that stay inside the chrysalis for 3 years before they emerge. This long time frame is typically due to environmental factors and not the metamorphosis process.