Effects of photoperiod on the timing of larval wandering in Drosophila melanogaster

ABSTRACT. A rearing method is described that will allow the use of well-timed larvae of Drosophila melanogaster (Canton S) in physiological investigations. Using a LD 16:8 h cycle and uncrowded rearing conditions, it was shown that photoperiod influences the departure of third instar larvae from the food (i.e. post-feeding larvae or wandering behaviour). Larval wandering occurs during the scotophase, suggesting a gated event, and does not occur in larvae raised under constant light or in overcrowded cultures reared in a LD 1623 h cycle. Although the data suggest, but do not prove, the existence of circadian gating, the rearing regimen described will provide well-timed post-feeding larvae for future studies.