This butterfly species, the anise swallowtail, graces our yard every summer. They start life on the wild fennel that grows in a corner.
Over the years, I have had the pleasure of watching all the stages of this butterfly’s life.
It begins when the female deposits eggs on the host plant, the fennel. The eggs hatch and tiny caterpillars–each one about the width of your pinkie–feed on the plant.
The caterpillars, also called larvae, have jaws. (Butterflies don’t have jaws, they have proboscis for drinking nectar.) They chew and chew and chew until their body grows so much the skin literally splits open.
Underneath this now-split skin is a new, more flexible skin that has been forming. The caterpillar continues chewing, and growing, until the skin splits again. This process, called molting, repeats four or five times.
Each skin is differently colored. At first they are black and white; the next caterpillar stage (aka instar) is orange and black. For the grand finale, the caterpillar is magnificent in green, orange, black, and blue.
More info here: Wikipedia Anise Swallowtail Butterfly.
Finally, in its last and fifth instar, the caterpillar once again splits the skin, but this time it spins one or two threads of silk, and attaches to a plant; forms the pupa or chrysalis. (See Life Cycle diagram below.)
Eventually the chrysalis ruptures and the winged insect crawls out. The flow of blood stops, the wings take some time to firm up, and the new butterfly flies away.
When we first moved to our rural property, I cut back the fennel, because it is an invasive plant and not native to our forest. Here in California and along the west coast, fennel is everywhere–abandoned lots, roadside ditches. I saw it yesterday on the freeway; four lanes of traffic speeding in each direction, and growing out of the median was fennel.
Fortunately for me, our fennel grew back the next spring, and that summer I found stunning caterpillars on it.
Since then I have pampered the fennel, and in late June, like clockwork, we find the caterpillars. They inhabit the plant stalks and eat the fronds, one little feathery piece at a time, voraciously devouring the plant.
In Native American and other cultures, the butterfly symbolizes transformation and change. Change is a key component to life on earth.
I don’t think there’s a creature more graceful and elegant for reminding us that change can be beautiful.
Photo credit: Athena Alexander
There are over 550 species of swallowtail butterflies; here are two other species that drink nectar on our property: