Few harbingers of spring are more spectacular to look at than the variety of butterflies that take to the skies after they emerge from chrysalis.
Although it is widely known that butterflies and moths go through a metamorphosis to turn into their finished forms, many are unaware just how many steps it takes for a butterfly to be ready to fly.
1. A butterfly begins its life as an egg, which a female butterfly lays on a particular plant that the species of butterfly prefers to eat. This is called a host plant. Butterflies are very particular about the type of plant that they eat. Certain species will only eat one type of plant or closely related varieties.
2. When a butterfly hatches from the egg, it is called a larva, or a first instar caterpillar. The insect is very small and does nothing but eat from the host plant.
3. Caterpillars are voracious eaters, and they grow very quickly. The trouble is that their skin cannot grow. A new, larger skin must be formed. To do this the caterpillar must molt its old skin so that the new, larger skin can emerge. As it eats, a caterpillar will go through a few stages depending on the species. It may become a second, third, fourth, and fifth instar caterpillar.
4. A caterpillar that has molted several times may look very different from its initial larval form. It will be much larger and may have different colors and features.
5. During the final molt, the discarded skin will become part of the chrysalis that will house the caterpillar as it pupates. The caterpillar spins a silk girdle that attaches it to a particular location, either on a tree branch or a plant stem.
6. Contrary to popular belief, butterflies are not formed in cocoons. Their pupa is called a chrysalis. Only some varieties of moths transform inside of a cocoon. In the chrysalis, the caterpillar is undergoing a rapid transformation. The chewing mouthparts are turning into the sucking mouthparts of a butterfly. Wings and antennae are also forming. The pupa stage is not merely a hibernation for the caterpillar. It is a time of very active growth.