Two trees, one a native and the other a sweet smelling exotic, host the voracious caterpillars of Jekyll Island’s largest butterfly, the Giant Swallowtail. Toothache Tree, Zanthoxylum americanum, grows wild on Jekyll Island in the dunes, on spoil piles, along the causeway, and at the river’s edge—some of the most severe habitats on the island. Go to the public boat ramp and look at the large tree to the left of the ramp right there by the water. The trunk and limbs have huge, sharp teeth. The “teeth” served for early herbal practitioners as a sign that this plant would help with toothaches.
And, sure enough, the sap contains properties that numb our gums and lips like Novocain! Not something we would like to eat—yet, the mottled gray, brown and white caterpillars (they look just like something a bird left behind) love the leaves of this plant. Giant Swallowtail larvae also enjoy dining on the sweet smelling citrus trees that grow in planters in the Historic District and the gardens of some homes. An orange tree in a pot by my kitchen door produced four oranges and eight Giant Swallowtails. Who cares if the leaves were chewed down next to nothing...what a crop!
The Giant Swallowtail, Papilio cresphontes, flaps its large wings with a seemingly lazy stroke but it is pushing air with up to 6.5 inches of gossamer membrane—no small feat. Look for large, dark brown (almost black) wings with a line of big, yellow dots stretching across the back from wing tip to wing tip and more yellow dots edging the lower wings. Lots of other swallowtail butterflies in this area have yellow markings along the edge of the lower wings but only the Giant Swallowtail has the yellow line running across the upper wings from tip to tip. The underside is a soft, creamy yellow with touches of blue and points of red here and there. It is hard to believe this beautiful creature started out looking like a fat bird dropping and then a dry, crusty bit of bark suspended from two thin lines against a twig of Toothache Tree or the sweet flowering Orange.
Photos by Christa Frangiamore. For more information about native plants, visit www.CoastalWildscapes.org.
Article posted May 1, 2009. 
