SICB+ Artificial Light at Night affects temporal synchronization in crickets Levy, K*; Wegrzyn, Y; Efronny, R; Ayali, A; Barnea, A; Tel Aviv University; Tel Aviv University; Tel Aviv University; Tel Aviv University; The Open University of Israel email@example.com
The rhythmic cycle of day and night is the most reliable Zeitgeber, synchronizing behavioral and physiological events in all organisms. Artificial Light at Night (ALAN) disturbs the perception of the natural light-dark cycle and thus negatively impacts the behavior and daily activity patterns of various animals. Our knowledge of the effects of ALAN is far from complete. The field cricket Gryllus bimaculatus is an established model in studies of insect physiology and chronobiology. We studied the effects of different lifelong ALAN intensities on the behavior of adult male crickets. All experimental groups were exposed to 12 hr daylight (40lux), and to one of four different night conditions: complete darkness (LD), 2lux ALAN (LA2), 5lux ALAN (LA5) and constant 40lux (LL). Stridulation and locomotion patterns of individual crickets were simultaneously monitored for five consecutive days and nights in a custom-made anechoic chamber equipped with a microphone and an infra-red camera. The period, median, variance, and acrophase of the daily activity rhythm were compared among experimental groups. Crickets under LD showed a 24h rhythm, stridulating at night and being locomotory active during the day. ALAN affected both the level and timing of the day and night activity, inducing differences between the stridulation and locomotion activity periods. Under ALAN, an increasing proportion of the animals demonstrated free-running patterns, followed by a loss of synchronized rhythmicity of the population. Moreover, we found a significant light-exposure-dependent increase of the variance of the period and the acrophase. Our findings demonstrate ALAN effects at both the individual and population levels. ALAN disrupts temporal synchronization of crickets’ day and night activity. We present crickets as good models for ALAN research.