During pupation, the larval structure disintegrates, the adult structure forms, and wings appear for the first time. The pupal skin splits and bites a way out, or the cocoon is excreted by secreting a fluid that softens the cocoon. Pupation is controlled by hormones.

After the pupa matures, it breaks out of the shell, but it takes a certain amount of time for the wings to dry and harden. At this time, the butterfly cannot avoid natural enemies, and it is a dangerous period. After the wings are stretched out, the butterfly can fly. The front and rear wings of the butterfly flap asynchronously, so the butterfly flies with great fluctuations.

Butterflies are insects that undergo complete metamorphosis, that is, they go through four stages in their life: egg, larvae, pupa, and adult.

Extended information:

Butterfly reproduction method: mating reproduction

Generally, male butterflies emerge earlier than female butterflies. After that, the male butterfly flies around, looking for the newly fledged female butterfly to chase and mate based on the sex pheromones emitted by the female butterfly.

Before mating, a courtship process is required, in which the pattern and color of the female butterfly and its pheromones play an important role. In addition, the structure of the external genitalia must match. If a female butterfly perched on a leaf has already mated, when the male butterfly flies, she will spread her wings flat and raise her abdomen high, and never take off. This is a sign that the female butterfly does not accept mating. Therefore, the male butterfly flies around for a while and then flies away; otherwise, mating occurs.

Sometimes a female butterfly that does not need to mate may encounter several male butterflies chasing each other while flying in the air. At this time, the female butterfly suddenly clutches her wings and lands rapidly. This kind of flight makes the male butterfly seem to be lost and does not know where the female butterfly is, so the female butterfly can escape.

The female butterfly's "escape from marriage" instinct is quite interesting. There are also some butterflies, such as most species of the family Sericidae. After mating, the female butterfly grows various post-mating derivatives at the base of the opening of the mating sac, which acts as an obstacle to prevent re-mating. It is a major characteristic for identifying species.

Baidu Encyclopedia - Butterfly

Baidu Encyclopedia - Pupa

Baidu Encyclopedia - Adult