Distalless expression in larval wing imaginal discs in both the Junonia and Bicyclus genus is correlated with the eyespots in adult wings in this Java video sequence. Use the blue Play button to initiate playback of the sequence.

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Butterfly Larval Wing Imaginal Disc: Second Instar Specimen: Butterfly Imaginal Disc Authors: Julie Gates, Eric Hazen, and Stephen Paddock

Butterflies and moths have a complex life cycle that consists of four separate stages. The first stage is the egg, which is fertilized during a typical insect mating ritual. Male butterflies and female moths secrete airborne pheromones that act as sexual stimulants to members of the opposite sex. In many instances, courtship is highly complicated and involves the coloration of the partners, a prenuptial courtship flight, and specialized "dances" that lead to mating. The sex attractant pheromones are complex biochemicals that probably determine most aspects of this mating behavior. Fertilized eggs are sometimes scattered by the female, but most butterflies and moths seek a suitable plant food source for their offspring. Most species lay a thousand eggs or more, but this number can vary with climate and the prevaling environmental conditions.

A short period of time after the eggs are laid, they hatch to produce caterpillars, one of the most complex and interesting stages in the life cycle of butterflies and moths. Caterpillars usually molt several times during their life by discarding their outer "skin" and forming a more elastic covering that allows expanded growth. Most of the life of a caterpillar is used to prepare for the next stage in development. They spend a majority of their time consuming nutrients to produce silk, which is used to spin a cocoon.

Caterpillars spin themselves into a silk cocoon, then transform into an immobile stage known as the pupa. During this stage, the pupa is transormed from a caterpillar into a butterfly or moth. The pupa stage can last weeks or even months, but when finished, a beautiful butterfly or functional moth breaks free from the cocoon to start the cycle again.