The life cycle of a butterfly is amazing. Butterflies have four life stages: egg, larva (caterpillar), pupa (chrysalis), and mature butterfly. One of the things that makes seeing and raising butterflies so enjoyable is that each of the four stages is distinct from the others.
The Egg of the Butterfly
The egg stage lasts on average 3-7 days, but this varies widely amongst butterfly species. To survive the long winter months, several species overwinter as eggs and go through diapause.
Caterpillar of the Butterfly
The egg develops into a little caterpillar. Most caterpillars’ first food is eggshell. The caterpillar is designed to be a “eating machine,” and it will grow in size thousands of times before pupating.
The caterpillar on the left is a young Black Swallowtail larva, whereas the caterpillar above is an older Black Swallowtail larva. Caterpillars will moult several times as their exoskeleton deteriorates. They will vary their appearance each time, sometimes dramatically.
Black Swallowtails, for example, have five instars or phases between the time they hatch from the egg and the time they pupate. The number of instars varies amongst butterfly species. The caterpillar in the above image is in its fifth instar and is about to pupate, or moult, for the final time before transforming into a chrysalis. The length of time a butterfly spends in the caterpillar stage varies based on the species and the environment in which it grows.
The caterpillar stage of a butterfly’s life cycle is regarded to be the most dangerous, with a high death rate. Caterpillars are threatened by weather, illness, parasites, and predators. Only a small percentage of the hundreds of eggs deposited by mature butterfly species survive to adulthood.
A Butterfly’s Chrysalis
On the left is a Black Swallowtail caterpillar preparing to pupate or form a chrysalis. It formed a silk mat and adhered to the bottom. To hold the chrysalis in place, the caterpillar spun a silk string around its body and tied it to the branch in the same way that a telephone linesman uses a leather belt to tie to the pole. Not all butterfly species attach in the same way. In fact, the majority of butterflies will dangle upside down from their silk pad.
The pupal shell of the caterpillar is growing beneath its skin. This shell can take on a variety of forms and shapes depending on the butterfly species. Once the caterpillar is firmly in place, the exoskeleton will split off, revealing the pupa. The eventual chrysalis of the Black Swallowtail will be green or brown depending on whether the caterpillar pupates on a green stem or a brown stick. Most butterfly species’ chrysalises survive about 1-2 weeks until the butterfly emerges. Several species overwinter as pupae, entering diapause in the fall and remaining so until the butterfly emerges in the spring.
The Adult Butterfly initiates and concludes the butterfly’s life cycle.
A butterfly’s wings are crushed when it emerges from a chrysalis. The butterfly will hang with its wings down and begin pumping fluids from its body into the wings in order to straighten them up. The butterfly must next wait many hours for the wings to harden and dry before flying away.
Most adult butterflies live for about 2-3 weeks, though this varies greatly between species. Adults who survive the winter (such as Monarch butterflies) can live for months (this is only true for the last generation Monarchs each summer that is migrating).
Female adult butterflies must find a mate and suitable plants to lay their eggs on in order to resume the butterfly life cycle.
Conclusion
We conclude that butterflies are the four stages of existence. Each of the four stages is distinct from the others, which is one of the reasons that seeing and raising butterflies is such an intriguing journey. Butterflies and moths have four life stages: egg, larva (the caterpillar stage), pupa (the chrysalis stage in butterfly development), and adult.