This beauty was visiting the butterfly weed, Asclepias tuberosa in my front yard about 2 weeks ago. It is known as the Eastern Tiger Swallowtail butterfly, Papilio glaucus, and is easily recognized by its large size and bright yellow and black coloration. It ranges from New England westward through the southern Great Lakes area through much of the Great Plains south to Texas and Florida. In the northern part of its range the females will exhibit a predominantly black coloration.
There may be as many as three generations of the butterfly here in North Carolina, beginning in March and lasting through mid-October. After mating, the females lay eggs on several tree species that include cherry, birch, willow, and tulip poplar. After hatching the newly emerged caterpillars begin feeding on the leaves. The first three instars (or stages) resemble bird droppings, which is probably a defense against predators. After molting to the fourth stage, they become green with a pair of black, yellow, and blue eyespots on the thorax near the head. Just prior to pupating the caterpillars turn brown.
One phenomenon peculiar to many butterflies is “puddling”. This term is used to describe a group of butterflies gathered together at a mud puddle where they drink the water and get essential minerals and proteins that they can’t get from just drinking sugar-rich nectar. They will also visit dung, dead animals, and urine deposits to get these essential nutrients.
In the mountains, a new species of swallowtail butterfly, Papilio appalachiensis, was described in 2002. Although it looks just like the Eastern Tiger Swallowtail, it can be distinguished by its much larger size, differences in coloring by being a paler shade of yellow with much less blue on the upper side, and a subtle difference in the appearance of the hind wing edge. It only occurs in the mountains of northwestern South Carolina to New England. There is just one generation a year.
In 2012, the North Carolina legislature declared the Eastern Tiger Swallowtail as the State Butterfly.
Ken Ahlstrom, Ph.D., Economy Exterminators, Apex, NC