Black Swallowtail Butterfly Lifecycle

The beautiful Black Swallowtail butterfly is one of the most commonly encountered garden butterflies. It mimics the toxic Pipevine Swallowtail to gain protection from predators. Like all butterflies, the black swallowtail undergoes a complete metamorphosis. The life cycle has four stages: egg, larva, pupa, and adult. The egg hatches in 4-10 days, the larva goes through five instars in 3 to 4 weeks, the chrysalis stage varies from 10-20 days and the adult butterfly stage is 6-14 days.
The host plants for Black Swallowtails includes members of the carrot family such as dill, parsley, fennel, carrots and others. The adult female lays yellow fertilized eggs on a host plant and the next generation begins.
After the eggs hatch the larvae feed on the host plant. As they grow they shed their skin to allow room for growth into the next stage or instar, until it is ready to enter the chrysalis stage.
The creation of the chrysalis is a fascinating process to watch. Once the caterpillar is ready to pupate it begins a search for a suitable spot. Once it chooses a spot it begins to lay down a silk foundation to secure itself to its chosen spot. If you look closely you can see it laying silk thread as it moves back and forth. In this process it creates two attachment points, one at the bottom with a patch of silk and one at the top with a long thread that it wraps around itself like a sling that supports its body. Over a couple of days the caterpillar will slowly transition into a chrysalis.
After 10-20 days in the chrysalis stage the butterfly will emerge or eclose from its chrysalis. The process of eclosion is controlled by hormones. As the hormones are released the chrysalis becomes softer and more transparent and allows the butterfly to push through the shell. When it first comes out the wings are wrinkled and folded. To straighten and dry the wings, it hangs upside down and meconium is pumped into the wing structure by wing movement and gravity. Once the wings are fully expanded, the meconium is pumped back into the body of the butterfly. After the wings are dry it will expel the excess meconium from its body and then fly away to begin the cycle again.