Impact of Different Wavelengths of Artificial Light at Night on Phototaxis in Aquatic Insects

Synopsis The use of artificial light at night (ALAN) is increasing exponentially worldwide and there growing evidence that ALAN contributes to the decline insect populations. One most conspicuous ecological effects strong attraction flying insects. In several studies, sources with short-wavelength emissions have been shown attract highest numbers Furthermore, stages aquatic insects are reported be more vulnerable than terrestrial This concerning because freshwater habitats likely affected by originates from human activity centers, which typically close freshwater. However, on insects, spend their larval phase (amphibiotic insects) or whole life cycle (fully in freshwaters, entirely understudied. Here, we investigated phototaxis different wavelengths intensities. We used floating traps compared four, near-monochromatic, lights (blue, green, red, yellow) two photopic intensities a ditch system, was not exposed previously. Similar (aquatic terrestrial) found positive stages. contrast stages, no clear preference for light. Overall, responsivity center visible range (green, yellow; 500–600 nm) significant all orders studied, nymphs Ephemeroptera did respond blue all. an adaption how attenuated systems, where only water itself but also variety optical constituents act as color filter, often like our case filtering out Therefore, living bodies live longer wavelength-dominated environments might therefore especially sensitive green/yellow conclusion, spectral sensitivities both should taken into account when planning lighting near