Flies’ colour preferences depend on the time of day

Alterations in lifespan and sleep/wake duration under selective monochromes of visible light in Drosophila melanogaster

Rapid technology development, exposure to gadgets, and artificial lights (with different monochromes) have disturbed our lifestyle and the circadian clock, which otherwise confers better regulation of behavioral patterns and sleep/wake cycles in most organisms including Drosophila melanogaster. We assay the effect of LD12:12 hr (light: dark) monochromatic lights (violet, blue, green, yellow, orange, and red) on the lifespan, activity, and sleep of the D. melanogaster. We observe a shortened lifespan under 12h of violet, blue, green, and yellow lights, while significantly reduced activity levels under the light phase of blue and green light as compared to their dark phase is observed. Significant increase in the evening anticipation index of flies under blue and green light alongside increased and decreased sleep depth during the day and night respectively suggests the light avoidance, while there is no effect of colored light on the waking time, daily active time, and sleep time. Thus, our study shows short and long-term exposure to certain colored lights in terms of reduced lifespan and locomotor activity, which cause qualitative as well as quantitative changes in the sleep of flies; probably as a sign of aversion towards a specific light.