MOISEFF, A; TESSIER, V; COPELAND, J; Univ. of Connecticut; Univ. of Connecticut; Georgia Southern Univ.: Signal jamming in a synchronic North American Firefly Photinus carolinus.

Fireflies communicate using flashes of light. The timing of the flashes is critical for effective communication to take place. If a female firefly sees flashes from more than one male, there is the possibility that communication will be disrupted (i.e., ‘jammed’). We examined this possibility in Photinus carolinus, a firefly in which several nearby males produce their species-specific flash pattern in synchrony. We measured the ability of female P. carolinus to respond to male-like flashes presented from one or two LEDs. The females were caged individually in clear 9 cm diameter petri dishes and had an unobstructed view of the LED or LEDs placed above them. Females were tested with synthesized flashes presented under 3 conditions: one or the other LED delivering the stimulus by itself, both LEDs synchronously delivering identical patterns, and both LEDs delivering identical patterns at variable delays. The number of times each female responded with at least 1 doublet flash to stimulation by either LED was expressed as a percentage of stimuli presented. Females responded at or near 100% when the stimuli were presented from individual LEDs or synchronously from both LEDs. When the pattern delivered to one LED was delayed less than 2.5 seconds relative to the other, the female responded near 100%. As delays between the two LEDs increased to 5 sec, the female’s response dropped gradually to 0%. Responsiveness increased as the delays between the LEDs were increased further. We interpret the failure to respond to either LED at certain delays as evidence of �jamming.� We suggest that the function of male synchrony is the minimize the female�s exposure to jamming by asynchronous flashes. Supported by the Research Foundation, Georgia Southern U. and U. of Connecticut.