Swallowtail Madness

Simply spectacular, swallowtail butterflies have a certain allure. Perhaps it's because they are such large butterflies which naturally demand your attention. Maybe it is their elegant tails that gracefully trail their expansive wings as they gently float by. Or simply that their movements flow so easily and look effortless. Whatever the reason they are here to be noticed.

Count them...5 swallowtails on joe-pye weed

Swallowtails adorn blooms in our garden from spring through autumn but the height of summer is when they are most plentiful. In fact, they are everywhere. They are constantly taking my breath away when I see them, especially en masse. I often look out the window and count twenty or more swallowtails covering the Joe-pye weed plants. Watching them flit and flutter through flowers is like watching a ballet where the whole garden is their stage.

They are often seen gracefully emerging from the woods, which is home to many of the host plants for the swallowtail species found in Georgia. They are in search of high energy nectar and they have come to the right place.

Joe-pye weed, butterfly milkweed, monarda, verbena, ironweed and swamp hibiscus are blooming right now and they are magnets for swallowtails. Earlier in the summer buttonbush and devils walking stick were calling to them (read more on Not All Plants Are Created Equally).

Spicebush Swallowtail on Swamp Hibiscus

Spicebush Swallowtail on Swamp Hibisucs

Eastern Tiger Swallowtails (Papillo glaucus) are one of the most recognizable butterflies. Not surprisingly since it is the state butterfly for 5 states (Delaware, Georgia, North Carolina, South Carolina, Virginia) but also because of their unmistakeably eye-catching yellow wings. But can you identify the male from the female?

The female is the showier of the two with her shimmery blue tones on her hind wings.

Eastern Tiger Swallowtail (female)

The male is unquestionably handsome in his own right. Without the distraction of the striking blue chevrons the tiger stripes that give this butterfly its name really stand out.

But the female is tricky because there is another form. She also comes in black which is a mimic of the Pipevine Swallowtail (Battus philenor). This dark morph is often found in areas where Pipevine Swallowtails are abundant. The pipevine plant contains aristolochic acid, which is toxic to some animals making the pipevine caterpillar and butterfly distasteful and hence a butterfly to mimic.

Eastern Tiger Swallowtail (female, dark morph)

Eastern Tiger Swallowtail (female, yellow)

To make things even more confusing, this female tiger swallowtail was spotted in our garden which looks like a blend of the dark and yellow forms.
 

Eastern Tiger Swallowtail, female (dark & yellow form combo)

Spicebush swallowtail (Papilio troilus) has been another predominant swallowtail in our garden this year. This woodland loving butterfly is a sensation. The hazy aqua green on the hind wings of the male is incredible.

spicebush swallowtail on butterfly milkweed

The undersides of the wing look very similar to other black swallowtails with two bands of orange spots. The differentiating marking is the third spot which is replaced with a blue dash.

Spicebush Swallowtail (third spot is replaced with blue dash)

Eastern Tiger Swallowtail (dark morph)

Despite the tell-tail signs I still sometimes struggle differentiating the dark swallowtails from one another, especially if I don't have a chance to inspect the underside. Is it a female tiger swallowtail in her dark form, male or female spicebush swallowtail? You give it a try.

The spicebush swallowtail will lay its eggs on Spicebush (Lindera benzoin) or Sassafrass (Sassafras albidum). We have both, and this season is the first time we've seen the caterpillars.

In the early instar stages the caterpillar looks like bird droppings sitting on a leaf. By the third or fourth instar the caterpillars are too big to pass as poop so they curl themselves up in the leaves to protect themselves against insectivorous birds and other predatory insects during the day. At night, the caterpillars emerge from the leaves to feed. Wrens are known to bite through the center of a folded spicebush leaf to eat the caterpillar, but if a predator were to see the caterpillar they would think twice before attacking this snake mimic.

 

In previous years we have enjoyed watching Black Swallowtails (Papilio polyxenes), Pipevine Swallowtails (Battus philenor) as well as Zebra Swallowtails (Eurytides marcellus) find refuge in our garden. This year those swallowtail species haven't been as common as the Tiger and Spicebush Swallowtails. Some years just seem to be more friendly to a certain specie(s) of butterflies than others.

So as we patiently wait for the monarch butterflies to find their way to our garden during their fall migration we will continue to be mesmerized by the allure of these beauties.

Swallowtail butterflies on butterfly milkweed