Tails of the Luna Moth
Entomologist Dr. Art Evans and VPM radio producer Steve Clark discuss one of the most spectacular moths found in North America, the Luna moth. What makes this harbinger of spring and summer so compelling?
Luna moths are easily distinguished from all other moths in North America by their green color and the long, sweeping tails of their hind wings. This spectacular moth was well known before it was formally described in the scientific literature by Carl Linnaeus in 1758. He applied the name “luna” in recognition of the crescent-shaped window on each wing, as well as in reference to the Roman moon goddess Luna. An account by London apothecary James Petiver first appeared in 1700 and was the first giant silk moth reported from North America. Later, Mark Catesby (1743) also illustrated an adult male. Likenesses of the luna moth have appeared numerous times in a variety of media ever since. It was even depicted on a postage stamp in 1987 as part of a series on North American wildlife. More recently, a luna moth was featured in a television commercial for a sleep aid.
Luna moths inhabit forests across most of the eastern United States and southeastern Canada. The mottled brown eggs are laid singly or in small batches on leaves of deciduous trees, especially black walnut, hickory, and sweet gum. The caterpillars hatch in a week and take about three weeks to mature. When mature, the large, bright green caterpillars pupate within a silken cocoon that incorporates a leaf. Caterpillars exposed to shorter day lengths in the fall become pupae that overwinter, while those exposed to long spring and summer days develop into pupae that will emerge in a week or so. Adults typically emerge from their cocoons in the morning, do not feed, and live about a week. They are strong flyers and are readily attracted to lights.
High-speed infrared videography reveals that the tails of the seemingly defenseless luna moth confounds the echolocation signals of bats. As it flies, the moth’s spinning appendages deflect the signals, directing the bat’s attention away from its body and toward the non-essential tails.
If you live near woods or in a well-treed neighborhood, perhaps you will be fortunate enough to see a luna moth at a light on a warm spring or summer evening. With their soft green color and long, flowing tails, these large and distinctive insects are truly a marvel of nature.
Learn about another giant silk moth that emerged right here at VPM’s studio on Sesame Street.