New Jersey Butterfly Club

A chapter of the North American Butterfly Association (NABA)

Giant Swallowtail

Papilio cresphontes

Identification: Very large—nearly 5" (ties with female Eastern Tiger Swallowtail as our largest butterfly). Above: Black with rows of bold yellow spots that cross near the apex of the FW. Below: Mostly yellow but with a row of blue spots across HW.

NJ Status and Distribution: Resident. Primarily a southern and western species that has increased dramatically in NJ since 2006, it is now locally common in the limestone belt in Sussex and Warren counties, especially where Prickly-ash grows. However, it is a strong flier and has turned up in many other counties.

Range Map-Giant Swallowtail

Habitat: Open, sunny, upland fields, wet meadows, and wood edges. In the northwestern counties, easily attracted to gardens with flowers such as Butterfly Bush, Purple Coneflower, and milkweeds. Especially fond of Wild Bergamot in upland fields, and Purple Loosestrife and New York Ironweed in wet meadows.

Flight Period: Adults begin to emerge in early May, and a second brood emerges in mid-July. Worn individuals can be found into late September. Extreme dates: North Jersey 5/4—9/24; South Jersey 8/12—9/25.

Caterpillar Food Plants: Common Prickly-ash (Xanthoxylum americanum—a native species of shrub), Hop Tree (Ptelea trifoliata—a native small tree), and other Citrus Family relatives such as Common Rue (Ruta graveolens-a garden herb).

Overwintering Stage: Pupa.

Good Locations: Kittatinny Valley SP, Whittingham WMA, Appalachian Trail Lands, and White Lake Natural Resource Area.

Comments: Fresh adults are nothing short of spectacular, and young caterpillars look like bird droppings, whereas older ones look like snakes when viewed head-on.


Giant Swallowtail

Whittingham WMA, Sussex Co., NJ, 6/3/11, on Cow Vetch.


Giant Swallowtail

Kittatinny Valley SP, Sussex Co., NJ, 7/26/12, on Wild Bergamot.


Giant Swallowtail

Kittatinny Valley SP, Sussex Co., NJ, 8/5/11, on Butterflybush.


Giant Swallowtail eggs

Eggs on Common Rue.


Giant Swallowtail egg

Egg on Common Prickly Ash.


Giant Swallowtail caterpillar

Day-old caterpillar.


Giant Swallowtail caterpillar

Middle instar caterpillar on Common Prickly Ash.


Giant Swallowtail caterpillar

Last instar caterpillar on Common Prickly Ash.


Giant Swallowtail caterpillar

Last instar caterpillar on Common Prickly Ash.


Giant Swallowtail caterpillar showing osmeterium

Caterpillar showing osmeterium.


Giant Swallowtail pupa

Pupa.


Common Prickly Ash

Common Prickly Ash in fruit, Vernon, NJ.