The largest phylum under the animal kingdom is Arthropods, and the largest class under it is Insecta or Hexapoda. They are characterized by segmented bodies, jointed legs and exoskeletons. Unlike other arthropods, their bodies can be clearly defined into three major regions:
Head- With clearly defined mouthparts, eyes and antennae.
Thorax- Segmented into three and has three pairs of legs.
Abdomen- Further segmented into many parts containing the digestive, excretory and reproductive organs.
They further include orders like Hymenoptera (ants), Diptera (mosquitoes), Odonata (Dragonfly), Lepidoptera and so on. The order Lepidoptera further includes moths and butterflies.
Caterpillar and Butterfly
The Lepidoptera order in Insecta further has various super-families. Butterflies are insects that come in the Superfamily of Papilionoidea. They come with colourful wings, a slender body and legs. Their body is covered with dusty scales, meaning the term Lepidopters- scaly wings.
The Lepidopteran life cycle has four stages, which are:
Egg- It is laid on leaf surfaces and stems by female butterflies. These tiny eggs can vary in colour and be cylindrical or oval. When the conditions are warm and favourable, they hatch into the larval stage, also called the caterpillar.
Larva (Caterpillar)- They are cylindrical shaped creatures with segmented bodies and six small eyes. During this stage, the caterpillars are very hungry, and they go around feeding on leaves constantly and moult repeatedly.
Pupa (chrysalis)- Once the caterpillar is mature; they form a covering or a vessel around themselves. Layers of skin harden this vessel to protect the larva inside. Once the larva has fully developed wings and transformed into the next stage, the vessel breaks and the butterfly breaks out.
Imago (Butterfly)- This is the adult stage where the butterfly has fully developed wings. When blood is pumped into the wings, they can fly and search for food and mates. After successfully mating, the female butterflies lay eggs on a leaf surface to continue the next cycle.
The process by which the egg undergoes drastic bodily changes to transform from larva into a butterfly is called metamorphosis.
Differentiating a Butterfly to Caterpillar
The primary differences between caterpillar and butterfly are:
These are some of the exciting differences between caterpillars and butterflies.
The Queen Alexandra’s birdwing is the largest species of butterfly amongst 20,000 different species.
The most massive caterpillar in the world is the Hickory Horned Devil.
Humans have three types of photoreceptors that allow us to see all these different colours. Butterflies have 15 types of photoreceptors that would enable them to see shades that we will never know of.
The 'ordinary colours' on the wings of the butterfly comes from the pigment in their body. This pigment melanin is the same as that found in humans. The shiny 'structural colours' on their wings result from the wing structure and its overlapping scales, causing iridescence or the glossy effect. This helps the butterfly in camouflaging and deceiving its predators.
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Q1. How Can Male and Female Butterflies be Differentiated?
We can identify male and female butterflies based on different physical characters like:
The size- Male butterflies may be smaller than females in most cases.
The abdomens of males are more slender than that of females.
Wing patterns may differ slightly for male and female butterflies. For instance, the male Monarch butterfly has a black dot in the hind wings that the females do not have.
The forewings may be more rounded for females, while it can be triangular-shaped for male butterflies.
In some butterflies species, the underdeveloped sex organs may be visible during the caterpillar stage, suggesting whether it would develop into a male or female.
There is sexual dimorphism in some species, which means that males and females would look completely different. Apart from these differences, there may be differences specific to various species. In certain species, the males and females can only be distinguished based on their internal anatomy since they may look identical on the exterior.
Q2. How are the Caterpillars of Moths Different from Butterflies?
Both moths and butterflies are lepidopterans, and their caterpillars look almost similar externally. No physical features are differentiating between the caterpillars of moths from butterflies. The caterpillars of each species of butterflies differ as drastically as they vary from moth caterpillars. However, since there are more moth species than butterflies, many caterpillars commonly seen would be of moths.
Some moth caterpillars also have specialities like having respiratory organs called spiracles that work underwater, the ability to swim in the water, sting venom on other creatures and some are even insectivores. Some caterpillars are also hairy in appearance. However, these dangerous types of caterpillars are rare and hence pose a low threat to humans. These features are mainly present as defences against the predators in their natural environment, such as lizards, birds, spiders, frogs, etc.