FROM SENSORY DISRUPTION TO ECOLOGICAL CONSEQUENCE: HOW ARTIFICIAL LIGHT AT NIGHT RESHAPES INSECT SENSORY ECOLOGY

Abstract

Artificial light at night (ALAN) is one of the fastest-growing forms of anthropogenic environmental change, and insects, most of which are nocturnally or crepuscularly active, are among the taxa most directly exposed to it. This review synthesizes the mechanistic literature on how ALAN disrupts the sensory systems insects use to interpret their environment, and traces how these disruptions propagate into behavior, reproduction, movement, and trophic interactions. Rather than treating ALAN as a generic stressor, we organize the evidence around distinct sensory channels: visual photoreception and the recently reframed dorsal-light-response mechanism underlying flight-to light behavior; polarization sensing in aquatic insects; circadian and photoperiodic photoreception at the molecular level; and the comparatively underdeveloped evidence base for chemical and acoustic communication. Evidence strength varies sharply across these channels and levels of biological organization: some findings are now supported by direct field-scale demonstrations (reduced nocturnal pollination visitation and fruit set; reduced caterpillar abundance under streetlighting), while others remain confined to laboratory assays or single case studies (evolutionary change in flight-to-light response; most acoustic effects). We deliberately preserve several unresolved controversies rather than forcing consensus, including the direction of net predation risk under ALAN, contradictory spectral preferences between general insect attraction and firefly courtship signaling, and the limited evidence that spectral tuning can substitute for reducing artificial light altogether. We conclude that understanding the sensory mechanism by which ALAN acts is necessary, not incidental, to predicting its ecological consequences, and identify priority knowledge gaps, with particular attention to multimodal sensory integration and the underexplored effects of ALAN on insect olfaction.