The Eastern tiger swallowtail butterfly is aptly named

The purple-flowered butterfly bush in my front yard has burst into bloom; already it’s luring swarms of Eastern tiger swallowtails to its rich nectar. The same is true for the lantana bush by the mailbox.

The strikingly beautiful, black-and-yellow butterflies, common all over Georgia, are often taken for granted, but I never tire of watching them visiting the blooms. No matter how many photos I’ve taken of Eastern tiger swallowtails, I always feel the urge to run and get my camera when I see one of them gently touching down, with wings spread wide, on a flower in early summer.

No wonder Georgia’s Legislature made the Eastern tiger swallowtail the state’s official butterfly in 1988. It is also the state butterfly of Alabama, Delaware, North Carolina and South Carolina, and the state insect of Virginia.

Early colonists, too, were mesmerized by the tiger swallowtail: It was the first American insect pictured in Europe; a drawing was sent to England from Sir Walter Raleighs’ third expedition to Virginia in 1586.

With its bright yellow color and four bold black stripes on each forewing resembling a tiger, the Eastern tiger swallowtail, along with the monarch, now is one of our most recognizable butterflies. With a wingspan of nearly 5 inches, it is also one of our largest butterflies. (Swallowtail butterflies in general are so-named because of the projections that extend from their hindwings.)

The female, though, may be showier. Her yellow hind wings have a band of blue with bright orange accents, while the male’s wings do not.

Some female tiger swallowtails, however, exhibit one of nature’s most intriguing mysteries: Instead of yellow, they are mostly dark brown to black. An advantage may be that “black morph” females resemble the poisonous pipevine swallowtail butterfly, which predators avoid. But why are only some tiger swallowtail females dark, and why do males not show this variation? Maybe it’s evolution taking place before our eyes.

Three times a year, the female lays her small, round eggs on leaves of host plants that include tulip poplar and black cherry trees. Newly hatched caterpillars resemble bird droppings. As they mature, they turn green with a large head and bright, false eyespots that may serve to scare away predators.

IN THE SKY: The moon will be full on Sunday — the "Green Corn Moon," as the Cherokee peoples called June's full moon, said David Dundee, Tellus Science Museum astronomer. Mercury and Venus are low in the west just after dark. Saturday night, Venus will appear near the bright star Pollux, one of the heads of the Gemini twins. Saturn is high in the east just after dark. Jupiter and Mars can't be easily seen right now.