The circadian control of calling song and walking activity patterns in male crickets (Teleogryllus commodus)

Calling song and walking activity patterns of the Australian field cricket Teleogryllus commodus were simultaneously recorded in LD and LL at constant temperature. The results were analysed with respect to their circadian structure: (1) Circadian properties were expressed more clearly in singing than in walking, with cases approaching arrhythmicity in the latter. Still, (independent) circadian control was proven for walking as in most cases the phase response of the recorded data was different from that of synthetic data produced by a model using the calling song as the only circadian source. (2) The phase angle difference between singing and walking rhythm (psi SIN/WAL) was usually smaller in LD than in LL, where values in the range of 180 degrees prevailed (Fig. 7). However deviations often occurred, during which the slopes of the instantaneous phase positions of singing and walking were different for several cycles, indicating individual periods. (3) Internal dissociation was also found following the exposure to 6-h pulses of low temperature. (4) After unilateral blinding of one compound eye during the last larval instar, which leads to splitting of the calling song rhythm, internal desynchronization was found between singing and walking. Additional removal of one optic lobe resulted in a common period and an abnormal psi SIN/WAL close to zero. (5) We interpret the results as follows: temporal calling song and walking activity patterns are controlled by the same compound circadian mechanism. Its bilaterally distributed pacemakers (Wiedenmann 1983) may dissociate under certain experimental conditions revealing their individual oscillatory properties in either singing or walking.