The Giant Swallowtail, Papilio cresphontes is a large butterfly in the Papilionidae family. They are easily identified by their bold yellow markings that contrast the black upperside; the underside is majority. This species ranges from southern Canada and New England, west across the northern Great Lake states, southward to Mexico, and Central and South America (1). In Maryland, they are found in many counties, but most often occur in Montgomery and Frederick. They are state rare with a rank of S2 (2).
The average male wingspan is 5 ½ inches and the average female wingspan is 5 ¾ inches (1). Both males and females have a black upperside with yellow diagonal bands across their forewings. Near the apex of the forewing, an “x” is formed from the crossing of the two yellow bands. They have a distinctive spoon shaped tail that is bordered in black and filled yellow (2). Their underside is mostly pale yellow with black veins and borders (1, 2).
The larvae are mottled brown with a cream to white colored saddle in the middle and top of the rear end. They often resemble bird feces (3).
Females lay their eggs singly on twigs and larval host plants (4) including, the Common hoptree (Ptelea trifoliata) and the Common Pricklyash (Zanthoxylum americanum) (2). Once the eggs hatch, a dark brown caterpillar with cream spots emerges and feeds on the leaves and young shoots. The chrysalis is light brown with spots of green and resembles a twig. They overwinter in their chrysalis form (4). In Maryland, the Giant Swallowtail has two flight periods from May to June and late July to August.
The Giant Swallowtail is found in woods, gardens, and fields with their preferred nectaring plants, milkweed (Asclepias syriaca) and goldenrod (Solidago canadensis) (5). Adults will also sip mud, and juices from manure (3).
Data from Maryland Biodiversity Project. Includes historical records and may overrepresent the current range of the species.
© 2020 Price Lab for Entomology, Courtney Rogall