The beautiful butterfly flutters from flower to flower, completely different from its appearance as a caterpillar or larva.

The transformation from caterpillar to chrysalis to butterfly is full of wonder and mystery.

Let’s go and search for the mysteries of the butterfly that make us want to ask, “How do they know that?” and “How do they do that?”



~Basic Information~

Lepidoptera, Papilionoidea Superfamily: Nymphalidae, Pieridae, and Papilionidae families.

The wingspan of a butterfly when its wings are fully spread can range from approximately 5mm to approximately 28cm.

Butterflies are distributed around the world, except in places such as the Antarctic continent, altitudes over 6,000 meters, and the center of deserts. There are approximately 18,000 to 20,000 species of butterflies worldwide, and approximately 250 species of butterflies inhabit Japan. The larvae of butterflies have different methods of protecting themselves from enemies and eating different plants depending on the species or subspecies. Even within their small bodies, they possess a mysterious wisdom and power to survive in harsh natural environments.



Butterfly (larva, pupa, adult) Q&A.

What is the world’s smallest butterfly and what is the world’s largest butterfly?


The world’s smallest butterflies are known to be the Small Blue, Koster’s Blue, and Taiwanese Blue butterflies, with a wingspan of approximately 1.2-1.5cm when fully spread. The Taiwanese Blue butterfly was also discovered in Yonaguni Island, Okinawa, Japan in 2003. Although it is thought to have flown from Taiwan, it has since been observed in Iriomote Island and Ishigaki Island as well.


The world’s largest butterfly is the Queen Alexandra’s birdwing, which is only found in limited areas of Oro Province in eastern Papua New Guinea. Its wingspan ranges from 20-28cm and it has a dream-like beauty with its yellow abdomen and metallic blue wings. However, due to its large size and beauty, it has been heavily hunted and its habitat has been destroyed, putting it in danger of extinction. Currently, it is designated as an endangered species and trading is prohibited.

What is the world’s oldest butterfly?

The oldest known fossil of a butterfly or Lepidoptera ancestor was found in northern Germany and is estimated to be 216 million years old. The fossilized scales were discovered by van Eldijk and van de Schootbrugge and published in their research paper “A Triassic-Jurassic window into the evolution of Lepidoptera.” This was during the time when dinosaurs were roaming the Earth, so it’s amazing to think that the ancestors of butterflies were fluttering around at the same time.

What’s the difference between butterflies and moths?


Butterflies and moths are insects of the same order, Lepidoptera, and cannot be clearly distinguished. In Japanese and English, butterflies are called “butterfly” and moths are called “moth”, but in French, both butterflies and moths are called “papillon”, and in German and other languages, the same word is used to refer to both butterflies and moths.


There is no clear distinction between butterflies and moths, as they both belong to the same order, Lepidoptera. In Japanese and English, butterflies are typically referred to as “butterfly” and moths as “moth,” while in French both are referred to as “papillon,” and in German both can be referred to by the same word as well. One characteristic difference is that butterflies are primarily active during the day, while moths are mostly active at night, although there are exceptions like the owlet moths which are active during the day. Butterflies tend to perch with their wings closed, while moths usually rest with their wings open, although some butterflies like swallowtails and admirals rest with their wings open as well. Additionally, when butterflies bask in the sun to warm themselves up, they often perch with their wings open. Butterflies have slender bodies and their antennae are usually club-shaped, while moths have bulkier bodies with antennae that vary in shape from pointed to feathered. However, some butterfly species like the nymphalid butterflies also have thick bodies and antennae with pointed tips or curved shapes. While butterflies are often considered to be more colorful and vibrant than moths, there are also many drab butterfly species and colorful moth species.

What do butterfly larvae eat?


The food (host plant) that butterfly larvae eat varies depending on the species. For example, even among the swallowtail butterflies, the orange oakleaf caterpillar feeds on citrus plants, the blue admiral caterpillar feeds on the leaves of camphor trees, and the Chinese yellow swallowtail caterpillar feeds on the leaves of the celery family. Since small larvae cannot find and move to their own food, mother butterflies lay their eggs on the host plant they have eaten and grown up on. If you give the larvae leaves other than their food, they will not eat them, or they may suffer from food poisoning and die.

How do mother butterflies distinguish their food plants?


So how do mother butterflies identify their food plants? Have you ever seen a butterfly tapping a leaf with its foreleg? This is called “drumming” and the butterfly is checking to see if it is the right food plant to lay its eggs on. Many butterflies have sensory hairs on the underside of their forelegs and use them to taste compounds during drumming to determine if it is a suitable place to lay their eggs, meaning if it is a food plant or not.

Why do different butterflies have different host plants?

Plants have evolved to produce toxic substances for self-defense because they cannot escape from insects and birds that try to eat them. Butterflies cannot eat the plants without overcoming their toxins. However, it is difficult for them to adapt to many different types of toxins, so they are believed to have adapted to specific plant toxins. For example, the Citrus Swallowtail has adapted to the toxins produced by plants in the citrus family, and the Black Swallowtail has adapted to the toxins produced by plants in the Apiaceae family.

How do butterfly larvae protect themselves from predators?


Butterfly larvae are masters of mimicry. For example, the larvae of the Swallowtail Butterfly look like bird droppings when they are young, but as they grow larger, they turn green and blend in with the leaves to protect themselves. When they become large enough to stand out, they display frightening eye-like patterns that they inflate when touched, intimidating potential predators. Some butterfly species, such as the Spicebush Swallowtail, are masters of mimicry and can even imitate venomous snakes. Additionally, some butterfly larvae emit a foul odor when touched, while others accumulate toxins from their food plants and become toxic themselves. The larvae of some species, such as the Painted Lady and Red Admiral, cut leaves to build their own shelters and hide from predators. Some interesting species, such as the hairstreak butterfly, attract ants by secreting a sugary substance and use them as bodyguards.

Do caterpillars and butterflies breathe?


Our breathing involves air entering the lungs, where hemoglobin in the blood receives oxygen and carries it to cells throughout the body through blood vessels. However, insects do not have lungs. So, do they not breathe? No, they do. Caterpillars, butterflies, and other insects breathe, but they do so in a different way than our lung breathing. Insects have a network of tubes called “tracheae” that deliver air throughout their bodies. Both caterpillars and butterflies have small oval-shaped openings on each side of each segment of their thorax and abdomen that they use to breathe. These are called “spiracles.” The spiracles have muscles that open and close them to allow air in and out while keeping dust and debris out with small hairs.

Why do butterfly larvae molt?

Insects have an exoskeleton, which is a hard outer covering that supports their bodies instead of having bones like us. Since the exoskeleton does not grow or expand, the inner body becomes cramped as it grows. To alleviate this problem, a larger skin is formed inside the old exoskeleton. When this new skin is ready, the insect sheds the old skin, which it then eats. This is because the old skin is a good source of nutrition, and leaving it around would attract predators that could harm the insect.


After hatching from an egg, a caterpillar goes through multiple molts, shedding its old exoskeleton and growing a new one to accommodate its increasing size. The number of molts varies by species, with some like the Silkworm Moth undergoing only 3, while others like the Swallowtail or White Butterfly undergo 4, and others like the Tortoiseshell Butterfly undergo 5 or more. After the final molt, the caterpillar enters the pupal stage and eventually emerges as an adult butterfly or moth.

What is the shape and color of a butterfly pupa?

The pupa of butterflies can be of two types: the chrysalis, where the head is up and attached with a silk girdle, and the cremaster, where the head is down and suspended by a silk thread. There are exceptions, such as the Common Grass Yellow butterfly, which belongs to the Pieridae family but makes a cocoon.


Butterfly pupae come in various colors. For example, the pupae of swallowtail butterflies and cabbage white butterflies have camouflage colors to blend in with their surroundings, such as green, light brown, and dark brown. Pupae that go into hibernation over the winter tend to be a pale orange or flesh color. Some species have pupae that are always the same color, such as the golden pupae of the great spangled fritillary.

How do butterflies become pupae? 1. Prepupa.

When a gluttonous mature larva suddenly stops eating and produces a large amount of diarrhea-like feces, it is a sign that it will soon become a pupa. Once it has made a sticky mess, the larva begins to move in search of a place to pupate. When it finds a suitable spot, the larva uses its mouth to spin a silk pad and attaches its rear end to it, creating a structure known as a “silk girdle.”

When caterpillars, such as those of the Swallowtail or White butterfly, are ready to become pupae, they stop eating and defecate a large amount of diarrhea-like waste, which signals that they are ready to pupate. They then start to move around to find a place to pupate, and once they have found a suitable spot, they create a “suspension pad” by spinning silk from their mouth and attaching their tail end to it. The caterpillar then curls up and repositions its head upwards before using its mouth to spin silk over its body, creating a protective covering. This process is known as the “pre-pupa” stage, and once it is completed, the caterpillar is ready to molt into a pupa.

How do butterflies become pupae? Part 2: Molting.

When the larva becomes a pre-pupa, its body gradually dries out and after 1 to several days, the back of the larva starts to split and shedding occurs. After shedding the skin, it transforms into a pupa! The pupa is like a mold of the butterfly, and you can see with the naked eye the parts that will become the antennae, legs, wings, and so on.

How does the larva transform into a butterfly inside the pupa?


When a larva hatches from an egg, it already has a small cluster of cells called “imaginal discs” that will develop into different parts of the butterfly’s body. When the larva becomes a pupa, it essentially dissolves most of its body into a soupy mixture. The nutrients from this mixture feed the imaginal discs, which start to divide and differentiate into the various body parts of the butterfly, including wings, eyes, and antennae.

Are butterflies the same as their larvae?

Yes, that’s right. Even though the body of the larva is dissolved and reconstructed into the body of the butterfly, the adult retains memories from its larval stage. Researchers at Georgetown University in the United States found evidence of this through an experiment in which they exposed tobacco hornworm larvae to a particular scent along with an electric shock. The larvae learned to associate the scent with the shock and would avoid it. When the same scent was presented to adult moths that had developed from those larvae, they also exhibited an aversion to the scent, suggesting that the neural pathways and memories from their larval stage were retained through metamorphosis into adulthood.


That’s right. In fact, the author had a similar experience when raising a caterpillar of the swallowtail butterfly. The pupa, which was very timid during its larval stage, remained just as timid after it metamorphosed into a butterfly. Although the body of a caterpillar dissolves into a gooey substance and seemingly dies, the author now believes that the life of a caterpillar is the same as that of a butterfly.

Are there pupae that cannot become butterflies?


Yes, there are pupae that cannot become butterflies. Some larvae are eaten by predators. Also, larvae or pupae that are stung by parasitic flies or wasps and have eggs laid inside them cannot become butterflies. The parasitic flies or wasps feed on the dissolved body fluids of the larva and develop inside the butterfly’s larva, but the parasitized larva dies. Butterflies that fail to emerge from the pupa and have undeveloped or deformed wings are unable to fly and cannot survive on their own to seek nectar from flowers. Out of 100 eggs laid, only one or two may successfully become butterflies.

How do butterflies emerge from their chrysalis (eclose)?


When the butterfly’s body is formed inside the pupa, as in the case of the swallowtail butterfly, the wing pattern can be seen through the pupal skin. And finally, it’s time for eclosion! The butterfly breaks out of the pupal shell, emerging first with its head and back. It then stretches out its legs and antennae and connects the two halves of its proboscis, which is split into two at first. The wings are initially wrinkled, but the butterfly pumps body fluid into the wing veins to expand them. The red or brownish liquid that comes out of its abdomen is excess body fluid. Once its wings have dried, the butterfly takes flight.

How fast do butterflies fly?


The flying speed of butterflies varies depending on the species, with the White butterfly and Swallowtail butterfly flying at around 14 kilometers per hour, while some species such as the Checkered Skipper and Admiral butterfly can fly at speeds of up to 50 kilometers per hour.

Why do butterflies have a powdery substance on their wings?

Butterflies and moths have scales called “scale powder” on their wings. Scale powder has the characteristic of repelling water, which allows them to fly even in the rain. In addition, the scale powder plays a significant role in regulating body temperature. Dark-colored scale powder absorbs solar heat and helps to warm the body, while light-colored scale powder prevents the body from overheating. The fine bumps created by the scale powder on the wings reduce air resistance during flight, assisting with flapping. Males also have scent scales called “androconia,” which are different from other scales and emit pheromones to attract females.


However, there are also butterflies and moths that have transparent wings without scales, such as the Asian Swallowtail butterfly and some species of hawk moths that shed their scales immediately after emerging from their pupal stage, resulting in transparent wings.

What do butterflies eat?


Butterflies feed on nectar as adults, while the larvae feed on leaves to grow. Some species, like the swallowtail butterflies, may also feed on tree sap rather than flowers. Occasionally, they may also feed on ripe fruits, sweat, or animal dung. To feed, butterflies use their proboscis, which is a straw-like mouthpart that evolved from their jaws. So, how do butterflies find their food sources? They use their eyes to see ultraviolet light, which allows them to locate nectar and sap. Nectar, for example, reflects ultraviolet light and appears as darker greens or blacks, enabling the butterflies to easily find flowers with nectar.

How do butterflies survive the winter?

Some butterfly species overwinter in different ways. For example, species like the Green-underside Blue, Pale Grass Blue, and Common Grass Yellow overwinter as eggs. The caterpillars of species like the Japanese Oakblue, Asian Swallowtail, and Purple Emperor hibernate and overwinter hidden under dry leaves. Some species like the Common Bluebottle and Swallowtail overwinter as pupae. Others like the Purple Hairstreak, Northern Pearly Eye, and Red Admiral hibernate motionless on the ground or on top of dried leaves.


It is also interesting to note that there are butterflies that can fly long distances without any problem and migrate to warmer countries like birds during winter. For example, the monarch butterfly travels back and forth from the United States to Mexico, covering a distance of up to 4,000 kilometers. In Japan, many of the painted lady butterflies that hatch in the summer migrate up to 2,000 kilometers to the southwestern islands or Taiwan in the autumn to hibernate. It is amazing to think about how these butterflies have acquired the knowledge and wisdom to survive the harsh winter.



Types of butterflies

Scientific NameCommon NameFamilySubfamily
ParnassiinaeParnassian butterfliesParnassiidae
SatyrinaeSatyr butterfliesNymphalidaeSatyrinae
PapilioninaeSwallowtail butterfliesPapilionidae
PieridaeWhites and yellowsPierinae
LycaenidaeGossamer-winged butterfliesLycaeninae
NymphalidaeBrush-footed butterflies
 -Admiral, tortoiseshell, etc.Nymphalinae
 -Meadow browns, etc.Satyrinae




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