Butterflies undergo a complete metamorphosis process that includes the eggs, caterpillar, pupa, and adult. Once they reach adulthood, they continue sexual reproduction in a specific season, lay eggs on selected host plants, and proceed to look for other mates (males) or pass away (females).
Overview of the Butterfly Life cycle

Eggs | the egg stage can last about 3-7 days, there might be up to 500 eggs on the host plant |
Larva | this stage can last for several weeks or months, depending on species, and caterpillars grow 100 times their original size |
Pupa | pupa stage last for 2 weeks or several months, the caterpillar slowly turns into a butterfly |
Adult | adult butterflies won’t change anymore, they can survive 2 to 3 weeks, some species live for several months |
Butterflies develop through a process called metamorphosis. Metamorphosis of butterflies has 4 stages: egg, larva, pupa, and adult.
The first stage of the life cycle of a butterfly is an egg. Adult female butterflies lay small eggs on plants. The amount of eggs a butterfly lays depends on the species of butterfly.
Some species can lay up to 500 eggs at once. They lay so many because only about 10 will make it to adulthood. The egg stage can last about 3-7 days.
The next stage is the larva stage, also known as the caterpillar stage. A tiny caterpillar hatches from the egg and eats the eggshell. The caterpillar significantly increases its body mass as it eats constantly.
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Caterpillars eat leaves and other plant parts, such as seeds. They will molt several times as they outgrow the exoskeleton.
Caterpillars grow up to about 2 inches long during this stage. This is the most dangerous life cycle stage, as they are exposed to many weather conditions, diseases, and predators.
Once the caterpillar is fully grown, it enters the pupa stage. All caterpillars create a protective shell called a chrysalis. Some chrysalides hang upside down, some support themselves on a tree branch, and some make a silk hammock.
The specifics of the chrysalis depend on the type of butterfly. Inside the chrysalis, the caterpillar’s body changes. It uses the food it ate during the larva stage to complete the metamorphosis. Inside the chrysalis, the caterpillar begins to take the shape of a butterfly. This stage can last for 2 weeks or several months.
The last stage is the adult stage. The chrysalis will become transparent right before the butterfly hatches. The new butterfly will emerge and wait for its wings to dry before flying. Adult butterflies are fully grown and will not grow or change anymore.
Now, they need to mate and lay eggs to start the life cycle again. The lifespan of a butterfly is about 2-3 weeks, but this varies between different types of species. Some species of butterflies can live for many months.
How do butterflies find mates?

Adult butterflies start searching for a mate immediately after hatching. If a female butterfly does not mate right away, she most likely never will. This will prolong her lifespan.
Male butterflies often mate with female butterflies that are emerging from their cocoons. This method makes mating for the male butterfly easier since the female has to wait until her wings dry. This prevents her from flying away from the male.
Both male and female butterflies release a scent to communicate with each other. They release specific pheromones to attract a mate. Butterflies also use color and sound to find their mate.
Butterfly Courtship dance
In many species, male butterflies perform a dance to impress the female. He will delicately fly around her and create pulses.
The female butterfly displays her acceptance by letting her abdomen protrude between her legs. She may also join in his dance to show her acceptance. Male butterflies often get rejected many times before successfully mating.
Butterfly Mating: an overview of the process
Once butterflies find a mate, they will connect the ends of their abdomens. As their bodies join, the male will pass sperm to the female. The male also transfers a nuptial gift of nutrients that the female can use to increase egg production.
Male butterflies mate with multiple female butterflies, but the male butterfly dies several weeks after using all of its sperm. A female butterfly is pregnant for about 3 weeks.
On the other hand, female butterflies mate once in their lifetime. They could mate in the spring, summer, or fall. The breeding season depends on their species. For example, the Monarch butterfly mates in February and March, and the swallowtail species mate from May onward.
Butterfly Anatomy
Male and female butterflies may have similar makeup but different genitalia. Their bodies have a head, thorax, and abdomen. Both genders of butterflies have antennae, proboscis, and palpi on their heads.
Their legs and wings are attached to their thorax. Their reproductive organs are in the abdomen.
The end of the abdomen differs between genders. Males usually have slender abdomens, while females usually have round abdomens. Males have claspers that they use to grasp onto the female’s abdomen while mating.
Egg Laying: when, where, and how
When | during spring, summer, or fall, depending on the species |
Where | on host plants located in specific habitats (meadows, roadsides, forests, gardens), on top of leaves, on the underside of the leaves, on stems |
How | eggs come out from the spermatheca, pass through the area where the male’s sperm has been stored and become fertilized, come out singly or in clusters |
Most butterflies lay eggs around March and April. Some species lay eggs in the fall.
The butterfly will find a host plant to lay her eggs on. The host plant will act as a protection and food source for the caterpillar. These host plants vary per butterfly species and can be located in butterfly gardens, roadsides, wood edges, or meadows.
The female butterfly will find the right plant in a shady spot near food sources for the caterpillar to eat once it hatches. Butterfly eggs could be found on top of or beneath leaves. They could also be on stems.
As the female lays her eggs, the egg comes out from the spermatheca. It passes through the area where the male’s sperm has been stored. The egg will be fertilized and then released.
Some species lay single eggs, and other species lay them in clusters. Some will wait a few moments before laying the next egg or move it to another host plant if the first plant is packed with eggs. That way, the adult butterfly ensures caterpillars have enough food to survive.
Most types of butterflies lay around 100 eggs. A large number of eggs ensure the survival of the species. Female butterflies die once they lay eggs.

Whitney has always admired the beautiful Kentucky scenery in which she resides. As a child, butterflies would often land on Whitney. Their beauty and constant presence inspired her to learn more about them. She now enjoys writing about the wondrous creature.