The Black Swallowtail

I would like to introduce you to my favorite caterpillar, the Black Swallowtail, Papilio polyxenes.

I knew I had not seen a Black Swallowtail butterfly in my garden for a few weeks so, I thought I might not have any caterpillars to take a photo of. 

I was so pleased when I saw a large caterpillar resting on a stem covered in the fresh morning dew – especially when it just happened to be a Black Swallowtail. The caterpillars, when almost mature, are uniformly colored with their soft green skin etched in jet black stripes and speckled with lemon yellow dots.  The caterpillar’s soft creamy foot pads adhered so tightly to the stem swaying in the breeze, it looked as though it would never let go. It was certainly an unexpected pleasure.

The early stages of these larvae look like bird droppings.  This is a method of camouflage that protect them from predators. I ran to get my camera and tried to get a good shot.  Not wanting to disturb the larvae, I sat down in the grass next to the garden bed and took the photo.

The Black Swallowtail butterfly is a graceful flyer swaying from left to right (not in a zigzag, but in a gentle glide swaying from side to side.)  The Black Swallowtail male and female butterflies are dimorphic, meaning that they have a difference in the coloration of their wing patterns.

Blacktail Swallowtail Host Plant

The host plants of the Black Swallowtail are in the parsley family such as carrots, parsley, dill and celery fennel.  I recall one afternoon late in the fall, a museum visitor brought in some Black Swallowtail caterpillars because they had eaten all the parsley in her garden and she was worried that they would not live.

I placed the caterpillars in a plastic shoe box with holes in the lid.  Inside the box I placed a slightly moist paper towel and some fresh organic parsley I purchased at the grocery.  The caterpillars were just fine with this method of alternative feeding.  They all pupated on the lid of the box and remained in good health. Within a few weeks time they were set free atop the 7th floor of the parking garage.  They gently took the breeze on down to the Cockrell Butterfly Center’s Demonstration garden and began their life cycle once again.

Stop by the Demonstration garden the next time you visit the museum and see if you can spot any caterpillars.