Moth Survival Increases Under High Pressure Sodium Lights


SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY
2021 VIRTUAL ANNUAL MEETING (VAM)
January 3 – Febuary 28, 2021

Meeting Abstract


1-5  Sat Jan 2  Moth Survival Increases Under High Pressure Sodium Lights Seymoure, BM*; Parrish, T; Egan, K; Irwin, D; Crooks, K; Angeloni, L; Living Earth Collaborative, Washington University; Colorado State University; Colorado State University; Colorado State University; Colorado State University; Colorado State University brett.seymoure@gmail.com

Anthropogenic light at night is growing spatially and in intensity globally while insects are on a global decline. Many nocturnal insects provide numerous ecosystem services and are attracted to anthropogenic lights at night resulting in decreased fitness, greater mortality and population declines. During crepuscular and night hours, moths are depredated by bats and birds, both of which are using vision to detect and prey upon moths. The visual detection of moths by predators is dependent upon the light environment illuminating the moth’s body, and anthropogenic light at night can differ drastically in the color (spectral composition) and intensity of light. Currently, High Pressure Sodium Lamps (HPS) and Light Emitting Diodes (LEDs) are the main light sources used by municipalities and these lights differ in spectral composition with LEDs being broad band and HPS being dominant in longer wavelengths of light (red-shifted). Using plasticine clay models of moths, we tested the survival of moths under different light sources (HPS and LED) as well as under no direct lighting in an urban setting to show that moths are more likely to survive under HPS lighting than LEDs and non-lit poles. Visual model analyses reveal that HPS lamps render moths more cryptic against their background than LEDs or ambient urban lighting. Although these results indicate that HPS lighting is the most insect friendly lighting, we further show that the artificial visual environment created by HPS is more likely to make prey detection by birds difficult and could perhaps shift an evolved visual predatory-prey dynamic in urban settings.

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