Fireflies are winged beetles that chemically produce light from their lower abdomen. They do this to attract mates and food, such as when fooling other bugs to fly toward them, and also to defend territory while warning potential predators away. The flashes are used for other forms of communication, but scientists have not yet fully deciphered their meaning.
There are more than 2000 species of fireflies in the world. While it's challenging to conduct surveys of their numbers, Lewis says she's not the only one who believes that the glowing insects are in decline. James Lloyd, aka the "Firefly Doc" at the University of Florida, said that he has noticed "there aren't anywhere near as many as there used to be." His colleague, Marc Branham, as well as University of Georgia biologist Kathrin Stanger-Hall have additionally seen the decline. In Japan, researchers have documented dramatically reduced numbers of the once plentiful firefly species Luciola cruciata.
Photo: Eastern U.S. firefly Photinus pyralis captured mid-flight. Credit: Art Farmer, Wikimedia Commons