Butterflies (and moths) are holometabolous insects. This means they experience the following distinct life stages: egg, larvae, pupae, adult.

 

Egg - butterflies begin life as an egg which is laid by the female after mating. The egg stage lasts a few days to many months (depending on the species). Some butterflies pass the winter as eggs.

 

Larva - The larvae emerge from the hatched eggs. They are essentially eating machines. Periodically, the larvae must shed its exoskeleton as it grows. Many butterflies pass through 3 or more larval stages as they continue to grow.

 

Pupa -  This stage is where the insect appears to be "resting." In actuality, the entire body plan is being reworked at a cellular level. This is the stage where the larva transforms into the adult.

 

Adult - This is the stage we think of as butterflies.

A note about terms - much of the descriptive words used for butterflies is based on Latin. Therefore, we refer to a singular larva and multiple larvae. Likewise, there is one pupa, and many pupae.