The article published today
by entomologists Andrew Moiseff and Jonathan Copeland reports the results of their study on the reproductive relevance of synchrony in the flashing of the North American firefly (Photinus carolinus
To conduct their study they placed a female in an appropriate laboratory environment containing artificial males that flashed at varying degrees of synchrony. They found that the females responded in an average of 82% to synchronous flashes compared to only 3% responding to asynchronous flashes.
The frequency of flashing not only is preferred by the females, but it is also important to them in selecting males from their same species over other males flashing irregularly or at different rhythm. In some species, males produce flashing that occurs rhythmically and synchronically with millisecond precision and which differs from the flashing frequency of the males from other species.
The researchers conclude that one function of flash synchrony is to facilitate the ability of the female to recognize her con-specific male and those that produce the more synchronous flashes, and reduce the visual clutter from other flashing males.
Light production in fireflies is caused by a complex chemical reaction that takes place in specialized light-emitting organs, usually located on a firefly's lower abdomen. The enzyme luciferase acts on the fluorescent compound called luciferin which produces light in the presence of oxygen, magnesium ions and Adenosine-triphosphate (ATP).
Fireflies start glowing even at the larval stage. However, at this stage bioluminescence serves a different function than it does in adults. It appears to be a warning signal to potential predators since many firefly larvae contain chemicals that are distasteful or toxic.