Wikijunior:Bugs/Caterpillar/Butterfly

What does it look like?

Monarch butterfly feeding on nectar from a flower.

Butterflies are common insects that have a worm-like body and highly colorful wings. The body and wings are covered with tiny scales that are best seen through a microscope. If you catch a butterfly by the wings some of the scales will peel off on your fingers. Butterflies are common in the garden. They can often be seen visiting flowers during day time.

Moths look similar to butterflies and they are closely related. Moths are nocturnal in nature, though, with stocky bodies. Most moths have dusky colors.

Where does it live?

Butterflies are very common throughout the world. In cooler climates they are especially common during spring and summer. You can find them in your own neighborhood or garden. Anywhere that there are many plants and flowers you can find butterflies. Some people grow gardens for the purpose of attracting butterflies. These are called "butterfly gardens." Butterfly larvae are called caterpillars. Each butterfly species eats specific types of plants. These plants are called "hosts." The caterpillar of the monarch butterfly feeds on the milkweed plant.

What does it eat?

Caterpillars eat their own egg shells as soon as they hatch in most cases. The larvae (caterpillars) feed on tender shoots and leaves. In most species larvae eat more than their own body weight. Caterpillar mouths are suited for cutting and chewing and have strong mandibles.

The pupae are dormant and do not feed.

All adult butterflies feed on liquid food. Adults have long tubular mouths which remain coiled under the head. These mouth parts can be extended while feeding. Butterflies feed on nectar and plant saps. A few feed on sap from fruits or fermented saps. In some species, the adults do not feed at all.

How does it defend itself?

Hairy caterpillars have spiny bristles. These bristles bother predators by lodging in the skin or mucous membranes. Some of these bristles also contain venom that can cause irritation.

Some caterpillars eat food that contains toxins. They store these toxins in their bodies even after they become adult butterflies. This makes animals that eat them sick. Bad tasting butterflies are often brightly colored.

Caterpillars and some butterflies use camouflage to avoid detection. They can be the same color as the plants where they live, or look like sticks or other common objects. The pattern on a butterfly's wings sometimes looks like the face of a much larger animal. This is thought to frighten off some predators.

The peacock butterfly shown as a larva, pupae, and adult, along with detail of the head.

What stages of growth does it go through?

A butterfly goes through four stages during its life. It starts life as an egg. It then becomes a larva and then a pupa, and finally an adult. During the larval stage, a butterfly is called a caterpillar. During its pupal stage it is called a chrysalis, and during the adult stage it is called an imago, which is the butterfly. Butterflies go through complete metamorphosis, which means that the adult form is very different from the juvenile form.

What special behavior does it exhibit?

Butterflies sense the air for scents, wind and nectar using their antennae. The antennae are very sensitive.

A butterfly tastes with its feet (called tarsi.) It picks which plant to lay eggs on based on the taste it senses when it lands on the plant.

Butterflies have four independent wings. This allows them to be nimble fliers.

Many butterflies migrate over long distances. One famous migration is the Monarch butterfly's which goes from Mexico to southern Canada. Butterflies navigate using the sun as a compass.

How does this bug affect people?

Butterflies are pollinators. They add beauty to gardens.

Caterpillars of many butterfly species are major pests of crop plants.