Black swallowtail caterpillars on parsley plant

See what I found on my parsley? A colorful swallowtail caterpillar.
Once it is old enough, it will form a chrysalis. It will overwinter in the chrysalis, meaning it won’t hatch into an adult until Spring. Next year this caterpillar will be a beautiful eastern black swallowtail butterfly.

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Black swallowtail

Life cycle of black swallowtail butterflies

Female butterflies lay single eggs on host plants. This is usually on the new foliage and sometimes on flowers. The egg stage lasts four to nine days. Next is the larval (caterpillar) stage lasting 10–30 days. The pupal stage is 18 days although the duration of these stages may vary depending on temperature and the host plants.

Caterpillars feed on a host parsley plant for nourishment. These caterpillars will transform into black swallowtail butterflies.

This parsley plant is covered in caterpillars. The black swallowtail caterpillar is often called the parsley worm because the caterpillar feeds on in. You can see how much of the plant has been eaten by the caterpillars.

Emergence from chrysalis

Winter is spent in the chrysalis stage. Adults will emerge from the chrysalis in the spring and seek out host plants. When an adult butterfly finally emerges from the chrysalis, it will wait a few hours for its wings to fill with blood and dry, before flying for the first time.

After the transformation, called metamorphosis, it will look like this butterfly visiting our butterfly bush.

The Eastern Black Swallowtail (Papilo polyxenes) is a common swallowtail butterfly. Both male and female Eastern Black Swallowtails are bluish-black with yellow spots on the wings. They also have two orange eyespots with black dots in the middle.

The male has a yellow band on the hind-wings with a blue cloud under it. The female has a row of yellow dots above a blue band. It’s easiest to remember that males have more yellow.

Life expectancy of black swallowtail

Compared to other butterflies, members of the black swallowtail are long lived. Because they are quick, they are able to avoid many predators. Adult butterflies are at the highest risk for danger when they are incapable of flight or are starved because of poor weather.

Some interesting facts about butterflies

A group of butterflies is sometimes called a flutter.

Many adult butterflies never excrete waste – they use up all they eat for energy.

Butterfly wings are clear. The colors and patterns we see are made by the reflection of the tiny scales covering them.

Butterfly wings move in a figure “8” motion.

Some butterfly species lay their eggs on only one type of plant.

Skipper butterflies fly so fast they could outpace a horse, but most butterflies fly at 5 to 12 miles per hour

Butterflies have a long, tube-like tongue called a proboscis that allows them to soak up their food rather than sip it.

Males drink from mud puddles to extract minerals that aren’t available in flowers. This behavior is known as “puddling.”