Courses
Courses for Kids
Free study material
Offline Centres
More
Store Icon
Store

Difference Between Larva and Pupa

share icon
share icon

Larva vs Pupa

Insects generally undergo metamorphosis to reach adulthood. Metamorphosis is defined as a biological process in which the animal undergoes physical development after its birth. The body structure of the animal changes vastly through cell growth and differentiation.


Larva

The Larva is the young form of many animals before they undergo metamorphosis to grow into adults. This is a kind of indirect development in many animals which include amphibians, insects, etc. All these animals typically have a larval stage in their lifecycle. The appearance of the Larva is very distinctive when compared to that of their adult form. The Larval stage of an insect general includes many structures that are not found in their adult form. The environment adaptability, as well as their food and diet, also is completely different from that of the adult version of the animal.


The larval population of a given amphibian or an insect has more susceptibility to survive from predators when compared to that of their adult population due to the distinctive environment where they live. For example, the larval stage of a frog is a Tadpole that lives exclusively in water and cannot survive outside the aquatic environment unless and until it reaches the adult stage which is called a frog that can live on both land and water.


While some larvae are capable of surviving alone until they mature into adults, there are some larvae that need the help of the adults to be fed. These include the Hymenoptera species in which the female adults are responsible for providing food to the larva.


(Image to be added soon)


Pupa

The pupal stage comes after the Larval stage. The lifecycle of an insect undergoes 4 different stages which are egg, larva, pupa, and imago (adult stage) respectively. The pupal stage of an insect is controlled and regulated by the hormones of the insect, unlike the larval stage. The stage where the Larva becomes the Pupa is called the Pupation. The cells present in the larval stage start growing rapidly. They then become various organs of the insect-like the eyes, wings, legs, etc of the insect. Every variety of insects has a different name for their pupa. For example, the pupae of the butterflies are called the chrysalis. Usually, the pupae are enclosed within a cavity called the shells or cocoons. 


There are Two Types of Pupae: Obtect and Exarate

  • In an Exarate pupa, the appendages are free whereas 

  • In an Obtect pupa, the appendages are very much attached to the body wall like the cocoon.


Again based on the mandibles the pupa can be classified under two varieties:


  • Adecticous pupa, where the pupae are without the articulated mandibles. 

  • Decticous pupa, where pupae are with articulated mandibles. 


Generally. The pupae are immobile and hence do not have much defence mechanism to defend themselves from the predators. That is when their external covering comes to their rescue. Either the pupa is covered with the shell or cocoon or they conceal themselves from the environment by going underground. In some varieties, the pupae are protected by other insects whereas a few varieties of pupae secrete toxic substances to protect them from becoming a meal of the predators. 


Depending upon different varieties of insects, the pupal stage may last up to a week or even years before they reach adulthood.


(Image to be added soon)


Difference between Larva and Pupa

The insects and a few amphibians undergo the lifecycle which includes the larval stage and pupal stage but the appearance and duration in each case are different from the other.



Larva

Pupa

1

The Larval stage emerges as soon as the egg hatches which is the first stage of the lifecycle of an insect.

The Pupal stage comes after the Larval stage.

2

This stage is much active 

The pupal stage is much more sedentary when compared to its larval stage.

3

The main role in the larval stage is to build up nutritional levels for better development in the future stages.

In the pupal stage, the morphology of the insect takes a drastic change. The cells present in the larval stage develop rapidly to give structure to the animal. 

4

Usually, in the larval stage of an insect, the appearance is much like a worm shape. For example, in a butterfly

The pupal stage of a butterfly is enclosed within a shell and is immobile. 

5

Much of the feeding takes place during the larval stage.

The pupal stage is a sedentary stage where no feeding takes place.


Complete Metamorphosis

When insects progress through the pupal, egg, larval, and adult stages, they are said to have complete metamorphosis. Butterflies, flies, moths, wasps, ladybugs, bees, and various beetles are examples of insects that go through a complete metamorphosis. Four steps are required for complete transformation. The more general word metamorphosis refers to two distinct processes, one of which is full metamorphosis, also known as holometabolous development or holometabolous, which is nearly entirely unique to winged insects. There are significant variations between larval and adult forms throughout full metamorphosis. This transition necessitates a substantial amount of energy and is divided into a number of alterations at various phases of the insect's lifespan. It is simply not possible to undergo a complete morphological and anatomical transformation in one sitting since the procedure demands so much energy.


Incomplete Metamorphosis

Not all insects go through so many stages of development. Incomplete metamorphosis refers to insects whose body shapes are the same from hatching to adulthood. They hatch from their eggs as small, underdeveloped replicas of their adult selves. These young are referred to as nymphs. Nymphs molt, losing their exoskeletons, allowing them to develop until they reach adulthood. Insects that undergo partial metamorphosis include grasshoppers, dragonflies, and praying mantises.  Incomplete metamorphosis occurs in termites, praying mantis, and cockroaches. Incomplete metamorphosis allows some of the earlier stages of the insect to reproduce successfully.


The Four Stages of Complete Metamorphosis

Egg Stage of Complete Metamorphosis: 

The egg contains all of the genetic information required for development and function, including the blueprints for imaginary discs. Imaginal discs are seen in insect embryos and develop into anatomical features of adult species. Insect eggs are generated in vast quantities and deposited on protected, concealed surfaces by the female ovipositor. The larval form's nutrition determines where the egg is placed.


Larval Stage of Complete Metamorphosis:

An insect larva's worm or maggot shape is generally a long cry from its adult form. Its principal purpose after hatching from the egg is to absorb energy in preparation for the massive morphological changes of the following stage of full metamorphosis. Larvae may also have imaginal discs or imaginal buds, which develop into adult anatomy. The majority of larvae will go through at least one instar, or larval stage, where the larva must shed its skin to allow it to grow.


Pupal Stage of Complete Metamorphosis:

The imaginal discs of the insect embryo and larva become active during the pupal stage. A meticulously scheduled sequence of cell death and cell growth occurs, in which larval cells die and are broken down to supply energy for the many processes required in the development of an adult insect. Adults must be able to reproduce, and the reproductive organs mature during this period.


Imago Stage of Complete Metamorphosis: 

Eclosion is the process by which an adult insect emerges from its pupa. Hormones secreted at the pupal stage loosen the shell wall, allowing the adult beetle to emerge. The pupal case is left behind as an empty shell, and the adult insect is exposed to the elements and predators for a period of time. Because all of the adult insect's wings are wrinkled and moist, it is unable to fly.


Want to read offline? download full PDF here
Download full PDF
Is this page helpful?
like-imagedislike-image

FAQs on Difference Between Larva and Pupa

1. What is complete metamorphosis?

A metamorphosis is termed when the insect undergoes different stages of the life cycle starting from the egg, larva, pupa, and then adult respectively. In complete metamorphosis, the adult stage looks completely different from the larval stage. In every stage, the appearance of the insect changes drastically. 


Similarly, not every insect or an amphibian undergoes complete metamorphosis. There are a few varieties of insects where the appearance of the newly hatched insect from the egg looks quite similar to the adult version. These particular juvenile forms are called the Nymphs. Nymphs shed their exoskeleton until they grow and reach their adult size. A few examples include the dragonflies and grasshoppers which undergo incomplete metamorphosis. 

2. What is a cocoon?

A cocoon is a protective covering for a pupa spun out of silk secreted by many caterpillars and moths. Depending on the type of insect, the cocoon can be soft or hard, translucent or opaque and of various colours. The pupae that lie inside the cocoon either cut their way out or secrete some enzymes that soften the cocoon thus helping the insect come out of the cocoon as an adult.

3. What is the difference between Neotonic Insects and Hyper Metamorphic Insects?

Wing formation is an energy-intensive process, and the generation of a female adult that closely resembles the larval form and lacks wings does occur on occasion. This is referred to as neoteny or juvenilization. On the other hand, at the larval stage, certain insects have highly distinct-looking instar shapes. Hypermetamorphic insects of the Strepsiptera groups show these extra alterations throughout the regular full metamorphosis process.  Examples of Neotonic Insects are the female trilobite beetle or bagworm moth. Various parasitic wasp, beetle, fly, and mantis-fly are examples of Hyper Metamorphic Insects.


The four phases of full metamorphosis are experienced by all neotenic insects. The earliest stages of parasitic instars are exceedingly mobile and tiny in comparison to non-hyper metamorphic insects, making it much simpler for them to locate hosts.

4. Give some examples of Complete Metamorphosis.

A wide range of insect orders is represented in complete metamorphosis instances. Although most holometabolous insects have wings, there are few families that have wingless adults. The order Lepidoptera (butterflies and moths) and Coleoptera (bugs) are the most well-known holometabolous insects. Other orders that feature holometabolous are Diptera (flies), Neuroptera (including lacewings, alderflies and mayflies), Siphonaptera (fleas), and Hymenoptera (ants, bees and wasps). Species that do not go through complete metamorphosis and instead appear as nymphs (through the mechanisms involved in partial metamorphosis) have their own orders.

5. How can I get more study materials for the Biology chapter Larva and Pupa?

Vedantu provides everything a student requires to prepare for the exam. The most recent grading scale and exam format were used to develop these study resources. You may download the material by clicking on the PDF link provided on the page, or you can download the Vedantu app to obtain the solutions for a single chapter. These PDFs are also useful for reviewing the topic before any competitive or entrance tests. The information was created by subject matter specialists with extensive expertise, and it is available on Vedantu's official website to clear up any doubt. Visit the Vedantu website and download the PDF version to acquire study materials for this Biology chapter.