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.

Habitat: Open, sunny, upland fields, wet meadows, and wood edges. 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 very late April/early May, and a second brood emerges in mid-July. Worn individuals can be found into late September. Extreme dates: North Jersey 5/4—10/19; South Jersey 8/4—9/28.

Larval Food Plants: Common Prickly Ash (Xanthoxylum americanum)—a native species of shrub, and other citrus relatives such as Common Rue (Ruta graveolens) (a garden herb).

Overwintering Stage: Pupa.

Best Locations: Kittatinny Valley SP, Whittingham WMA, Appalachian Trail Lands, and White Lake NRA.

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