Spicebush Swallowtail: Stunning Papilio troilus Butterfly Uses Mimicry

Summary: Spicebush Swallowtail (Papilio troilus) is a stunning New World butterfly with a passion for mimicry and puddling and with a bright orange hindwing spot.

underside of Spicebush Swallowtail (Papilio troilus) with hindwings' orange spots, nectaring lantana, Capels Mill, southwestern North Carolina: John Flannery (DrPhotoMoto), CC BY ND 2.0, via Flickr

Papilio troilus is a New World butterfly native to Canada and the United States. Papilio troilus claims North American homelands from southwestern Ontario in east central Canada southward across the eastern continental United States to the Atlantic and Gulf coasts, with a westward extent into the Great Plains states of Kansas, Nebraska, Oklahoma and Texas.

Strays occasionally veer as far north as North Dakota or even further to Canada’s western province of Manitoba; as far south as Cuba; and as far west as Colorado.

The genus name, Papilio, derives from the Latin word for butterfly.

Carl Linnaeus (May 23, 1707–Jan. 10, 1778), Swedish botanist, taxonomist, and zoologist extraordinaire, sought inspiration from classical mythology in his selection of specific, or species, names. The species name, troilus, conjures the mystique of one of the world’s most famous bloody confrontations, the Trojan War which raged in the 13th or 12th century BCE. Prince Troilus, one of the many sons of King Priam of Troy and his second wife, Hecuba, was the fatal target of Greek hero Achilles early in the war pursuant to a prophecy that Troy would only fall if the adolescent prince died before adulthood.

Papilio troilus has the common name in English of Spicebush Swallowtail.

Spicebush reflects the metamorphic insect’s most common host plant in the laurel family (Lauraceae), the spicily aromatic spicebush (Lindera spp.) that features three New World species: bog spicebush (Lindera subcoriacea); common spicebush or Benjamin bush (Lindera benzoin); and southern spicebush (Lindera melissifolia).

As a woodland butterfly, Spicebush Swallowtails favor woodsy habitats such as parks, pine barrens, wooded swamps and deciduous woodlands.

Spicebush Swallowtails are attracted as well to open, grassy areas such as fields, roadsides, and yards.

Spicebush Swallowtails also seek damp environments offering opportunities for puddling, extracting moisture and nutrients from mud or damp sand. Puddling often appears as socialization, with Spicebush Swallowtails gathering along with other butterfly species.

Clover (Trifolium spp.), honeysuckle (Lonicera spp.), jewelweed (Impatiens capensis) and thistle (Cirsium arvense) are favorite nectar sources.

Spicebush Swallowtails belong to the Papilionidae family, known as swallowtails because of the distinctive tail that trails from the bottom of each hindwing. The black tail usually measures about 0.35 to almost 0.5 inches (9 to 12 millimeters) in length.

As a member of the family including the birdwing butterflies, the world’s largest butterflies, Spicebush Swallowtails are unmistakably large, with wing spans measuring 3 to 4 inches (7.5 to 10 centimeters).

Coloring of upper sides presents a stunning harmony of dark brown or black, blue or blue-green, orange and white. Black and an edging of ivory spots prevail on forewings. Hindwings feature black, banded with blue for females and blue-green for males, and edged with a margin of bluish or ivory spots.

A bright, orange spot at the base of the wings is unique to Spicebush Swallowtails. The underside of the hindwing is splashed with orange spots.

Spicebush Swallowtails are able to discourage predators through their resemblance to foul-tasting Pipevine Swallowtails (Battus philenor).

Spicebush Swallowtail caterpillars progress from resembling bird droppings to being mistaken for smooth green snakes (Opheodrys vernalis).

Spicebush Swallowtails enjoy puddling in the graveled edge of the parking lot at the nature walk located 4 miles (6.4 kilometers) south of my house. In July 2015 two Spicebush Swallowtails amicably puddled, along with a bevy of Orange Sulphurs (Colias eurytheme), as my siblings and I crossed the gravel to access the recreational area’s paved road for our walk.

Upon our return about 20 minutes later we noticed that the larger of the two Spicebush Swallowtails was flying agitatedly up from the gravel and back down, repeatedly landing near a prone dark shape that close inspection revealed to be the second of the duo. With no signs of trauma, the dead Spicebush Swallowtail seems to have died, on the wing or in the midst of puddling.

Back home Spicebush Swallowtails daily regale me with their happy flights in all areas of my yard.

Spicebush Swallowtail (Papilio troilus) nectaring milkweed (Asclepias spp.), Capels Mill, southwestern North Carolina: John Flannery (DrPhotoMoto), CC BY ND 2.0, via Flickr

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

underside of Spicebush Swallowtail (Papilio troilus) with hindwings' orange spots, nectaring lantana, Capels Mill, southwestern North Carolina: John Flannery (DrPhotoMoto), CC BY ND 2.0, via Flickr @ https://www.flickr.com/photos/drphotomoto/9307880727/

Spicebush Swallowtail (Papilio troilus) nectaring milkweed (Asclepias spp.), Capels Mill, southwestern North Carolina: John Flannery (DrPhotoMoto), CC BY ND 2.0, via Flickr @ https://www.flickr.com/photos/drphotomoto/9012414948/

For further information:

Cech, Rick, and Gary Tudor. Butterflies of the East Coast: An Observer's Guide. Princeton NJ; Woodstock UK: University of Princeton Press, 2007.

Hall, Donald W., and Jerry F. Butler. “Spicebush Swallowtail Papilio troilus.” University of Florida/Institute of Food and Agricultural Sciences (IFAS) > Entomology and Nematology Department > Featured Creatures. October 2000; latest revision: August 2013.
Available @ http://entomology.ifas.ufl.edu/creatures/bfly/spicebush_swallowtail.htm#dist

Layberry, Ross A., Peter W. Hall, and J. Donald Lafontaine. The Butterflies of Canada. Toronto: Univerity of Toronto Press, 1998.

Mickley, James. “Papilio troilus.” Animal Diversity Web > Insecta.
Available @ http://animaldiversity.org/site/accounts/information/Papilio_troilus.html

“Spicebush Swallowtail.” Canadian Biodiversity Information Facility > Species Bank > Butterflies of Canada.
Available @ http://www.cbif.gc.ca/eng/species-bank/butterflies-of-canada/spicebush-swallowtail/?id=1370403265779

“Spicebush Swallowtail Papilio troilus.” Butterflies and Moths of North America > Species Search.
Available @ http://www.butterfliesandmoths.org/species/Papilio-troilus