The butterfly is both the beginning and the end of a complex chain of life known as metamorphosis. The butterfly begins as a tiny egg perched on a host plant, emerges as a caterpillar that eats until it reaches full growth and then hides away in a chrysalis. As the chrysalis splits, a magnificent butterfly emerges. This amazing transformation may take weeks or years to complete.
Before mating, the adult female seeks out a host plant suitable as a food source for young caterpillars. Surprisingly, she uses her legs to "taste" the plants to find the appropriate host. Eggs are deposited, usually on the underside of leaves. They may be laid in clumps or laid singly.
Eggs hatch in approximately 10 days, although in some species the eggs sit over winter and hatch in the spring. Caterpillars emerge and begin eating the leaves of the host plant. As they grow and become too large for their current skin, they shed and eat the old skin. They are voracious eaters and spend nearly their entire lives eating.
Once they have reached full growth, the caterpillar seeks a place to create a chrysalis. The caterpillar attaches itself to a branch and enters the pupae stage. Hormones in the caterpillar's body are thought to signal the formation of the chrysalis. Chrysalises are generally well-camouflaged since they are helpless to avoid predators. The outer shell is usually hard and shiny and can range from a magnificent gold to shades of green and brown, depending on the species.
The caterpillar remains in the chrysalis for as little as 2 weeks as the body is transformed into the body of a butterfly. Some species sit over winter, and the butterfly emerges in the spring. A few days before the emergence of the adult butterfly, the chrysalis becomes translucent, and the butterfly colouring and wings are visible though the chrysalis. The chrysalis splits, and a new butterfly is born.
The newly hatched butterfly emerges with small wet wings and a round plump body. Fluids gathered inside the body must be pumped into the wings. The body pulses for several minutes as the wings enlarge and straighten. Excess fluids are discharged from the body. This fluid, called meconium, is red and resembles blood. Once the wings dry, the butterfly can take flight, and the amazing cycle of life begins anew.