The life cycle of this butterfly can be categorized into four developmental stages. The first stage is the egg, the second the caterpillar (larva), the third the pupa (chrysalis), and the last the adult, which heralds the emergence of the most beautiful creature on Earth.
The caterpillar begins to develop inside, drawing upon the yolk material inside the egg for nutrition. It takes the caterpillar about 3 to 5 days to eat a hole in the egg case and emerge onto the surface of the leaf.
This caterpillar is about 0.1 inches long and weighs about 0.55 milligrams. Its body is covered by nine chocolate-colored rings apart from a black head, three pairs of front true legs with claws, and five pairs of prolegs extending backwards. This feature adds a unique and functional form to its body.
It also has a stomach, mouth, and a silk gland among other characteristics of a full-grown caterpillar. Its rapid growth leads to four or five molts (shedding of its external skin).
It now stops eating and spins a white silk pad on a stiff object, attaching itself by its two rear prolegs to the silk pad. Once this is done, it hangs head-down in a J-shape in a seemingly inactive state for about 12 hours.
Once this stage ends, the caterpillar begins to convulse in rhythmic jerks, breaking off its outer skin. At this developmental stage, its head capsule and 16 legs are shed in about 60 seconds, with the emergence of a pupa or chrysalis that is 1 inch long and 0.4 inches in diameter.
Jade-green in color, the chrysalis at this point has 24 metallic appearing gold spots surrounding half its upper abdomen. The remaining part is surrounded by 12 metallic-like gold spots.
As the caterpillar's head capsule is discarded, it enters the chrysalis stage with the only ability to distinguish light from darkness. The inside portion of the chrysalis that is located below the gold crown turns to a jade-green liquid within the first 16 hours, because of the disintegration of the parts of the caterpillar's body.
The outline of the butterfly's wings can now be viewed through the somewhat transparent outer shell. One can also see a pattern of lines that mark the position of the future butterfly proboscis (tubular sucking organ, used to suck sweet nectar from the flowers), first and second pairs of legs, and also the two antennae.
It takes approximately 2 hours for the wings to dry, and the butterfly is full-grown. It has six legs and four beautiful wings that are surrounded by a narrow black border studded with white spots. At this stage, the adult has two compound eyes and is about 1.3 inches long and 0.15 inches wide and weighs about 0.41 grams.
At this time, some butterflies return the long distances to where they were born while others fly only part of the distance to Texas or the lower southern states. Those located to the west of the Rocky Mountains travel to the west coast from Baja California to the north of San Francisco.
There are others that come from British Colombia in the autumn to winter in California. These butterflies have life spans of about six weeks.