Georgia Southern University Researcher Uncovers Mystery of Fireflies

July 8, 2010

Research co-authored by a Georgia Southern University professor has uncovered the reason why certain types of fireflies seem to light up the night sky all at once. Called firefly synchrony, research suggests the magical sight on summer nights is actually an important signal that ensures a female firefly is flashing at the correct species of male firefly for mating — in spite of the fact that there are many male fireflies flashing in her vicinity.

The results of the research by University of Connecticut physiology and neurobiology professor Andrew Moiseff, Ph.D. and Georgia Southern University biology professor Jonathan Copeland, Ph.D. will be published in the July 9, 2010 edition of Science, which is the world’s premiere journal of scientific research. The article points out that while scientists have hypothesized for centuries about the reasons that male synchronic fireflies simultaneously flash in a repeated, rhythmic pattern, this is the first time anyone has conducted experiments to find out why.

“Scientists know male fireflies light up as they fly around looking for a mate. Timing is everything in fireflies, with the time from one male flash to another male flash saying ‘I am a member of this species’, and the time from the male’s flash to the female’s response flash, being key,” said Copeland. “Both have to be maintained for the flash code system to work. In Southeast Asia, a species of male firefly typically has the timing down to milliseconds, and firefly species found in North America have their synchrony down to a few milliseconds, too. We wanted to find out what the purpose of this precise timing was.”

For the research, Moiseff and Copeland conducted experiments using live female fireflies and virtual male fireflies. Some of the virtual male fireflies–simulated by computer synthesized LED (light emitting diode) flashes – lit up with the flashes in unison synchrony (all at exactly the same time). Copeland and Moiseff then caused the virtual fireflies to flash like the specific species being studied, but with random delays. The researchers found that female fireflies overwhelmingly responded to the unison synchronized flashes and virtually ignored the random ones.

“This research leads us to propose that the simultaneous flashing is more than a beautiful quirk of nature – it is actually a mechanism to ensure the survival of the species,” said Copeland. “The precise, unison synchronized flashing pattern is a way for a female firefly to cut through the visual clutter of a field of many flashing male fireflies in the night sky and make sure that the she keeps flashing at her own male.”

To read more about the research methods and the research conclusions, please visit www.sciencemag.org.