Studies on circadian rhythm of the house cricket, Gryllus domesticus L.

Abstract

An investigation was made of the daily rhythmic behaviour of the house cricket, Gryllus domesticus L. Continuous aktograph records were obtained from individual crickets under various lighting conditions. In LD 12:12 (12 hr of light alternating with 12 hr of dark) adult crickets showed a marked rhythm of locomotory activity set to the start of the dark period. This activity rhythm persisted for several days in constant dark or constant light and was circadian. The phase of the adult activity rhythm could be reset by changing the phase of the alternating LD conditions. The patterns of locomotory activity in LD 12:12 showed marked individual variation. Some crickets showed one daily peak of locomotory activity following the onset of the dark period, while others consistently showed a second peak prior to the onset of the dark period. Last instar larvae generally did not show the marked locomotory activity of the adult type. A daily rhythm of feeding and drinking was found in both adults and larvae. Sexual behaviour of adults was also noted to occur with a daily periodicity. It was found that adult crickets could re-entrain their rhythm of locomotory activity to a new LD régime after either the ocelli or the compound eyes had been blacked-out, but not when both ocelli and compound eyes were covered.