Quantifying the attractiveness of broad‐spectrum street lights to aerial nocturnal insects

Abstract

Abstract1. Sodium street lights, dominated by long wavelengths of light, are being replaced by broad-spectrum, white lights globally, in particular light-emitting diodes (LEDs).These white lights typically require less energy to operate and are therefore considered "eco-friendly". However, little attention has been paid to the impacts white lights may have upon local wildlife populations.2. We compared insect attraction to orange (high-pressure sodium, HPS) and white (metal halide, MH and LED) street lights experimentally using portable street lights and custom-made flight intercept traps.3. Significantly more (greater than five times as many) insects were attracted to white MH street lights than white (4,250 K) LED and HPS lights. There was no statistical difference in the numbers of insects attracted to LED and HPS lights for most taxa caught. However, rarefaction shows a greater diversity of insects caught at LED than HPS lights. Policy implications.With the current, large-scale conversion to white light-emitting diode (LED) lighting, our results give insight into how changes to street light technology may affect wildlife populations and communities. We recommend avoiding metal halide light installations as they attract many more insects than competing technologies. We highlight the need to tailor LED lighting to prevent disturbances across multiple insect taxa.

Effects of street lighting technologies on the success and quality of pollination in a nocturnally pollinated plant

“…Regardless of the cause of the observed interactions, our finding that the direction of the effects of HPS lights and LEDs can interact with other factors (here, light regime and distance from the light) is interesting in the context of several recent studies into the relative attractiveness of LEDs and other lamp types to nocturnal invertebrates (Huemer et al 2010, Pawson and Bader 2014, Wakefield et al 2018. Although these studies all compared the abundance of insects attracted to LEDs and other lamp types, including HPS, they together report that LED does not differ in attractiveness from HPS (Wakefield et al 2018), or that LED is more attractive than HPS (Pawson and Bader 2014), or that LED is less attractive than HPS (Huemer et al 2010). Our results may partially explain this conflict, by suggesting instead that the relative ecological impact of the two lighting types can be substantially altered by other, related variables, such as the duration of lighting.…”

“…, Pawson and Bader , Wakefield et al. ). Although these studies all compared the abundance of insects attracted to LEDs and other lamp types, including HPS, they together report that LED does not differ in attractiveness from HPS (Wakefield et al.…”

“…Although these studies all compared the abundance of insects attracted to LEDs and other lamp types, including HPS, they together report that LED does not differ in attractiveness from HPS (Wakefield et al. ), or that LED is more attractive than HPS (Pawson and Bader ), or that LED is less attractive than HPS (Huemer et al. ).…”

“…As discussed above, we predicted that PN lighting would have a lesser impact on pollination, and therefore greater pollination success and quality than FN lighting. Previous studies have variously reported LED lighting to be both more (Pawson and Bader 2014) and less (Huemer et al 2010) attractive to nocturnal invertebrates than, or to have no effect relative to (Wakefield et al 2018), HPS; therefore, while we tested for an effect of change in lighting type, we did not make a prediction for the direction of any such effect.…”

“…) attractive to nocturnal invertebrates than, or to have no effect relative to (Wakefield et al. ), HPS; therefore, while we tested for an effect of change in lighting type, we did not make a prediction for the direction of any such effect.…”