Meeting Abstract
Males of many acoustically communicating insects synchronize their calls with those of neighboring conspecifics. In most species, males either advance or delay the timing of individual signals in response to a single stimulus pulse, whether the signal of a neighbor or an artificial stimulus. The pulse rate (10-14 Hz) of Neoconocephalus ensiger males is considerably faster than the rate of synchronized signals in other insect species (0.5-3 Hz). We found that they make no timing adjustments in response to single stimuli pulses. During interactions with conspecifics, males made only small adjustments to their pulse period in a single cycle. Large-scale timing adjustments only occurred in response to large delays between males. When entrained to a stimulus with a faster pulse period, males briefly interrupted calling; they resumed calling largely synchronized with the stimulus. Throughout the stimulus, males made gradual changes to their pulse period, similar to those observed during pair calling. After the stimulus ended, pulse periods increased over several minutes, but did not return to their pre-stimulus values. Thus social context influenced pulse period in N. ensiger. These results indicate that N. ensiger males synchronize calls by adjusting their intrinsic pulse period, resulting in the long-term effects, while all other synchronizing insects described adjust the timing of individual pulses then continue to call at their previous period immediately after. This unique mechanism may be a necessity because of neurological processing times and the scale of timing adjustments that can be made within a single N. ensiger pulse cycle.
