The life cycle of a butterfly includes a process called metamorphosis where each butterfly goes through 4 stages from an egg to a larva, then to a pupa, and finally, they turn into an adult butterfly. These 4 stages of a butterflies life varies slightly depending on the specific type of butterfly, as discussed below.
As we age, we change. We are shaped by our experiences and the passage of time. Many biological factors appear and change that causes us to experience things like puberty. Many organisms go through changes as they age. The frog grows from an egg and becomes a tadpole that exists in the water with gills and is more like a fish than a frog.
As time goes on, the tadpole’s body begins to grow legs and lose their tale. Eventually, the tadpole goes from something like a fish to a frog, capable of being on the land or underwater. Other species go through more dramatic changes, like the clownfish. Clownfish colonies consist of males and females with a few young ones taking care of each other. If the largest female dies or there are any shifts in the hierarchy of the colony, the male clownfish becomes a breeding female.
This process preserves the balance of the colony and ensures that there is always a mating opportunity for continued survival. We also see extreme changes as they occur on land. Moths and butterflies experience dramatic changes as they age, changing from larval stages, like caterpillars, to grown moths or butterflies. If you did not know that they were the same species, it would be easy to assume that caterpillars and butterflies are two completely separate species. These changes are facilitated by the pupa stage, which is seen in many organisms.
The life cycle of a butterfly:
Butterflies are insects that belong to the Lepidoptera order, which also includes moths. They are identified by their large, often colorful, and striking wings that have become synonymous with beauty. Adult butterflies generally live for weeks up to a year, and during that time some make mass migrations across long distances while others stay more local. Once female butterflies have found a mate and copulate, they lay their eggs on leafs, which are firmly attached via a glue-like substance that hardens quickly.
|Chrysalis||The process of shedding their outside layer of skin|
|Food (butterflies)||nectar from flowers|
|Food (caterpillars)||Plant eaters (herbivores)|
|Life Cycle||Four parts: egg, larva (caterpillars), pupa (chrysalis), and adult|
|Number of wings||4|
|Species||Between 15,000 and 20,000 different species of butterfly|
|Taste Receptor||Located on butterfly feet|
|Type||Butterflies are insects|
Egg size and shape vary between species but they are usually covered in a protective layer of wax, called chorion, to prevent exposure to the outside world. The eggs usually hatch within a few weeks unless it is laid in the winter time, which will result in a resting phase and then the egg will hatch in spring. Once the caterpillars are hatched, they spend their time searching for and consuming food. As the caterpillar continues to eat and grow, it will eventually get to a point where certain hormones, like the prothoracicotropic hormone, are produced to initiate the next stage of development: the chrysalis stage.
The Chrysalis Stage
To begin the chrysalis stage, a caterpillar will find a safe spot on a leaf and attach itself to it using some silk. It will then molt for the last time, which causes it to shed its outer layer and reveal the chrysalis underneath. Now some caterpillars will spin a cocoon of silk to cover the chrysalis, but most caterpillars just have the exposed chrysalis. They are generally brown colors to blend into the environment and hide from any potential predators, but there are some more colorful kinds.
Once the caterpillar is within the chrysalis, the process towards becoming a beautiful butterfly can finish. The caterpillar releases enzymes that digest all of its tissues except for imaginal disks. Imaginal disks are specialized sacs of cells that are present in the butterfly since its time as an egg. The imaginal disks are made with the purpose of becoming the different parts of the butterfly in the adult stage. In most species, they stay inactive until this chrysalis stage, but there are a few species in which they slowly activate and develop in the caterpillar stage.
Nonetheless, they are fully expressed and activated in the chrysalis stage. The liquidized body of the caterpillar feeds the imaginal disks and they slowly develop into the wings and the many different body parts of the butterfly. There are some species that keep their nervous system intact throughout this process and possibly carry over knowledge from their previous stages into adulthood. The chrysalis stages last about a few weeks, though some species can last months to years, and once the butterfly is fully grown it releases an enzyme to break down the chrysalis and frees itself. Once it is freed, it must wait for its wings to dry before it can go off and begin its adult stage.
Why Does The Pupa Stage Exist?
There are many insects and other organisms that undergo metamorphosis like the butterfly. Moths go through a similar cycle and pupa phase as the butterfly. Flies move from eggs to larval stage, maggots, and finally to a pupa stage that transforms it into an adult fly. Frogs do it as they move from tadpole to adult. Many insects undergo an incomplete metamorphosis where the adult stage looks like the larval stage but more mature and larger. There are even fish species that undergo metamorphosis. Its prominence throughout the insect world and many other species speak to how successful of a strategy it is for survival.
Scientists estimate that metamorphosis appeared around 280 to 300 million years ago based on existing fossil records and insect biological and developmental data. The working theory is that a mutation or series of mutations occurred that resulted in early forms of metamorphosis because previously insects did not undergo this process. It became successful because the larval stages did not have to compete with the adult stages for the same resources as they had their own specific needs for continued development and reproduction. This diversification of resources allowed populations to grow larger and pass on their genes to future generations, which survived longer because there were more of them.
Scientists are not completely sure of the development of this process and more time and improvement to genetic technologies would be needed to paint a more accurate picture of the evolution of metamorphosis. Regardless, it is a very successful process that has allowed the continued existence of these wonderful and amazingly beautiful creatures.*NOTE: New DOI's are registered weekly Friday and may not function until then.