Impacts of Artificial Light at Night on Nocturnal and Diurnal Insect Biology and Diversity

Abstract

Artificial light at night (ALAN) is leading to light pollution on local and global scales. Reflected and scattered light contributes to skyglow over cities and large industrial complexes. ALAN is one of the key drivers of insect declines in the Anthropocene era. This is the likely consequence of perturbations in circadian clocks by extension and even abolition of the dark phase of the diel cycle, which affect reproduction and foraging. Bioluminescent insects that use light as sexual signals are severely affected by ALAN and may be under sexual selection for even brighter signals. The phototactic response of insects to light is also causing mortality due to increased predation and altered activity. Mitigatory measures are urgently needed to stem insect declines and to ‘protect’ the role of insects in community ecology. New satellite technology for ALAN measurement is urgently required. There are many research gaps, such as the effect of ALAN on diurnal insects and on interaction networks, that need to be filled.

Exposure to a nocturnal light pulse simultaneously and differentially affects stridulation and locomotion behaviors in crickets

“…Our findings indicate the importance of darkness for timekeeping in nocturnal insects, and present the harsh, and fast effects of a pulse of light or chronic dim-ALAN on activity rhythms and courtship behavior of the crickets. The findings indicate that not only can life-long or night-long exposure to ALAN alter animal behavior ( Rich and Longcore, 2006 ; Levy et al, 2021 ; Borges, 2022 ; Dominoni et al, 2022 ), but so too can a transient light exposure, such as a single pulse of ALAN ( Rotics et al, 2011 ; Spoelstra et al, 2018 ; Levy et al, 2022 ). This aspect should be added to the other possible effects of ALAN, as it may become a stressor when frequently experienced, or even entrain individual behaviors, as shown for the cricket ( Germ and Tomioka, 1998 ).…”

When Night Becomes Day: Artificial Light at Night Alters Insect Behavior under Semi-Natural Conditions

“…The daily rhythmicity of light and darkness serves animals for the perception of time (Aschoff, 1954;Borges, 2022) and is the most important environmental cue and Zeitgeber, synchronizing internal and external events through entrainment of the animal's circadian clock mechanism (Aschoff, 1954;Beer & Helfrich-Förster, 2020).…”

“…Artificial light at night (ALAN), the use of anthropogenic outdoor illumination during the night-time, has become prevalent (Falchi et al, 2019;Kyba & Newhouse, 2023) and is increasing worldwide by about 3-6% annually (Hölker et al, 2010). ALAN disrupts the natural light-dark cycle, impacting animals' daily activity patterns and altering their temporal synchronization (Borges, 2022;Helm et al, 2017;Levy et al, 2021). It has been shown to have severe effects on human health (Zielinska-Dabkowska et al, 2023), on wildlife (Duarte et al, 2023;Rich & Longcore, 2006), and on the environment (Giavi et al, 2020;Jägerbrand & Spoelstra, 2023;Owens et al, 2020;Stewart, 2021).…”

“…The daily rhythmicity of light and darkness serves animals for the perception of time (Aschoff, 1954; Borges, 2022) and is the most important environmental cue and Zeitgeber , synchronizing internal and external events through entrainment of the animal’s circadian clock mechanism (Aschoff, 1954; Beer & Helfrich-Förster, 2020). Circadian rhythms, as well as daily activity patterns, are manifested in many behavioral patterns, such as locomotion, sleep, foraging, and singing, as well as in physiological processes, including hormonal regulation and gene expression (Beer & Helfrich-Förster, 2020; Rich & Longcore, 2006; Touzot et al, 2022).…”

“…The daily rhythmicity of light and darkness serves most animals for the perception of time (1, 2) and has been reported to be the most important Zeitgeber , synchronizing internal and external events through entrainment of the animal’s circadian clock mechanism (2, 3). Circadian rhythms are manifested in many behavioral patterns, such as locomotion, sleep, foraging, and singing, as well as in physiological processes, including hormonal regulation and gene expression (3, 4).…”