Introduction
Butterflies and moths belong to the order Lepidoptera, which is the second largest in the class of Insecta (Ohno & Otaki, 2015). A caterpillar becomes a butterfly in a series of four stages, which make a complete lifecycle. Each stage is distinct from the others with different processes and goals taking place. In diverse species, the length of each stage differs, but the goals remain the same. For instance, the first stage can take between a few days and several weeks before progressing to the next level. This paper discusses the four stages (egg, larvae, pupa, and adult), which are involved in the transformation of a caterpillar into a butterfly.
Eggs
In the first stage, a female butterfly lays eggs on a leaf. In most cases, the small and round eggs are held together closely. Five days after the eggs have been laid, a small worm-like organism is hatched. This worm-like creature is known as a caterpillar (Johnson, 2017).
Caterpillar (Larvae)
A larva is a long creature also known as a caterpillar. After being hatched, caterpillars are hungry, and thus they start feeding on leaves starting with the one where the eggs were laid on. One of the characteristics of caterpillars is that they eat all the time, and thus they grow rapidly (Johnson, 2017). Ultimately, the bulging body cannot fit into its skin due to continuous eating. Consequently, the old skin is shed to allow the growth of a new one in a process known as molting (Christiani, n.d.). This shedding of the skin can happen over four times during the growth phase of a caterpillar. The reason for continuous eating at this stage is because the consumed food is stored for later use in adulthood.
Chrysalis (Pupa)
After the caterpillar is fully grown, it stops eating, and it transforms into a pupa, which is also known as a chrysalis. Depending on the species of the butterfly, the pupa can be hidden in leaves, suspended under branches, or buried under the ground. The chrysalis adopts the color of the surrounding environment as a survival mechanism to avoid being seen by other animals. In most cases, the pupa is encased inside a protective cocoon of silk (Puiu, 2018). The period taken during this stage varies depending on the type of the butterfly with some taking months and others as long as 2 years (Puiu, 2018).
Chrysalis is the most critical stage of the lifecycle of a butterfly. At this phase, the pupa starts changing into a butterfly. The pupa begins by digesting itself by releasing enzymes whose function is to dissolve its tissues. However, some of the tissues are highly organized into a group of cells, which are called imaginal discs, and they cannot be digested by the enzymes (Ohno & Otaki, 2015). As the transformation process continues, the pupa grows one imaginal disc for every adult body part.
The pupa then digests all its tissues apart from the imaginal discs, which are used as sources of protein for quick cell division in the process of formation of all adult body parts such as legs, wings, and antennae. In some species, certain parts of the caterpillar, such as muscles and nervous system are maintained in the adult butterfly (Ohno & Otaki, 2015). At the point where the pupa is fully disintegrated, the lifecycle moves to the final stage.
Adult Butterfly (Imago)
The last stage is called the adult stage. An adult butterfly is also known as an image. At this stage, the chrysalis opens and the butterfly comes out. As the image emerges, the wings are soft, damp, and they are folded around its body (Johnson, 2017). Due to the tedious process of coming out of the chrysalis, the imago is tired, and thus it rests. After the butterfly has regained energy, it pumps blood into its wings to prepare them for flying. The blood allows the wings to start flapping, which is the initial stage of flying. At first, flying is problematic, but a butterfly learns quickly and after getting accustomed to the exercise, it flies around looking for food. Finally, it starts looking for a mate, lays eggs on a leaf, and the lifecycle starts all over again.
Conclusion
Butterflies go through a lifecycle of four stages, which include egg, larva, pupa, and adult. The time taken at each stage differs depending on the species of the butterfly. In the first stage, a mature female butterfly lays small and round eggs on leaves after which they hatch into caterpillars within days or weeks depending on the species. The caterpillar is the second stage of the lifecycle and it eats continuously until it matures.
In the third stage, the mature caterpillar stops eating and forms a chrysalis, which is a protective cover to allow the metamorphosis to take place. Within the cocoon in the pupa stage, the caterpillar digests itself by releasing enzymes. The complete digestion of the caterpillar forms a butterfly, which comes out of the cocoon in the final adult stage. After learning how to fly, the adult butterfly finds food and mate before laying eggs for the lifecycle to start again.
References
Christiani, A. (N.d.). The lifecycle of a butterfly. Web.
Johnson, S. (2017). Facts about butterfly eggs. Web.
Ohno, Y., & Otaki, J. M. (2015). Live cell imaging of butterfly pupal and larval wings in vivo. PLoS ONE, 10(6), 1-21.
Puiu, T. (2018). How caterpillars gruesomely transform into butterflies. Web.