Key points are not available for this paper at this time.
Fireflies can duplicate both faster and slower rhythms of artificial light. Since the interval between the pacer signal and the firefly's flash of the next cycle approximates the firefly's normal free-run period, it is suggested that the pacer signal resets the flash-timing oscillator in the brain, thus providing a mechanism for synchronization.
Hanson et al. (Fri,) studied this question.