The four steps of the endangered beauties: the lifecycle of a butterfly

The butterfly and moth develop through a process called metamorphosis. Translating from Greek that means transformation or change in shape. Insects have two types of metamorphosis. Grasshoppers, crickets, dragonflies and cockroaches have incomplete metamorphosis. Their young (nymph) usually look like small adults but without wings. Butterflies, moths, beetles, flies and bees have complete metamorphosis. The young (larva) are very different from the adults and usually eat different types of food.

There are four stages in the metamorphosis of butterflies and moths: the egg, the larva (caterpillar), the pupa (chrysalis) and the adult butterfly. Each of these stages is unique to individual species of butterflies. Depending on the type of butterfly, the life cycle of a butterfly may take from one month to a whole year.

Egg: The Hatching Stage

A butterfly enters life as a very small oval, round or cylindrical egg. The shape depends on the type of butterfly that laid the egg. Eggs can be laid in spring, summer or fall depending on the species. Females lay a lot of eggs at once so that at least some of them survive. The eggs are usually laid on the leaves of plants, which afterwards will become the food for the hatching caterpillars. The mother uses a glue-like substance to “stick” the egg to the leaf. The egg has a small, funnel-shaped opening for water and air to enter. It also contains nutrients for the caterpillar to grow inside.

Caterpillar: The Feeding Stage

Butterfly larvae are called caterpillars. Tiny caterpillars hatch from the eggs. The first meal for most caterpillars is the eggshell. Then caterpillars start eating the leaf they were born on. That’s why it is very important for the mother to choose the right kind of leaf for her eggs – each caterpillar type has its own preferences. 

Caterpillars do not stay in this stage for very long. They have to grow quickly, so they eat continually. Their exoskeleton (skin) does not stretch or grow, so they “molt” (shed the outgrown skin) several times during their growth. Each time their appearance change, sometimes quite dramatically. Caterpillars can grow 100 times their size during this stage and increase their body mass thousands of times. Food eaten at this time is preserved and used later as an adult.

The caterpillar stage is considered to be the most dangerous in the butterfly lifecycle as the mortality rates are very high. Caterpillars are subject to weather conditions, disease, parasites and predators. Many adult butterfly species lay hundreds of eggs with only a few surviving to become adults.

Pupa: The Transition Stage

When the caterpillar has reached its full size, it turns into a pupa. The pupa of butterflies is also called a chrysalis. This transformation looks like a change from a resting caterpillar to a shell-like covering. The pupal shell is developing underneath the caterpillar’s skin. It can take many forms and shapes depending on the species of butterfly. Once the caterpillar is firmly in place the exoskeleton will split off exposing the pupa. Depending on the species, the pupa can be suspended under a branch, hidden in leaves or buried underground.

From the outside, it looks as if the caterpillar is resting, but inside the body is undergoing an incredible cellular transformation or “metamorphosis”. The transformation consumes so much energy that the pupa loses more than half of its original weight. The limbs and organs are all transformed by the time the pupa is ready to emerge as a butterfly. The time a butterfly spends in the pupa stage varies greatly per species, ranging from a few days to a year.

Adult: The Reproductive Stage

The adult butterfly emerges from the chrysalis with its soft wings folded about its body. It happens because the butterfly had to fit new parts inside of the pupa. The butterfly then hangs with its wings down and pumps the wings with fluids from its body in order to straighten them out. It had to wait several hours for the wings to harden and dry before flying away.

Having accomplished that the butterfly starts flying and searching for a mate. Adult butterflies always seek a chance to reproduce. The fertilized female finds the right type of leaf to lay eggs on and starts the life cycle over again. The lifespan of most adult butterflies is about 2-3 weeks but it can vary greatly among species. Species that overwinter as adults can live for several months.

Apollo butterfly’s lifecycle

The apollo butterfly goes through all of the abovementioned phases of life. The butterflies are on the wing in Central Europe in the lowlands generally from the end of May to July/early August and in high altitudes from June to early September. In the Southern Alps, the first adults appear in early May.

The butterflies breed between the months of June and July. Apollo females usually mate shortly after emerging from pupae, males – on the second or third day. During mating, the males deposit a gelatinous secretion on the abdomen of the female which prevents the female from mating a second time. The female butterfly is capable of laying up to several hundred eggs on the leaves of plants. They have a round shape with a radius of a millimetre, smooth in texture. Caterpillars hatch from the eggs between April and June. The larvae are black with small orange spots. Immediately after hatching, they start feeding actively. Further transformations require a lot of energy. While maturing, the caterpillars molt their skin five times. After they have finished their molting process they fall to the ground and turn into a chrysalis. After two months in the ground, the cocoon opens and a butterfly comes out. It takes around three months for Apollo to turn into an actual butterfly.

The process repeats over and over again. The lifespan of Apollos from larva to adult stage lasts one year. Laid by an adult butterfly, the eggs hibernate and then after a series of transformations, they turn into butterflies, striking us with their beauty.

Further reading

The Life Cycle of Moths and Butterflies by Mary E. Walter