Pollination and fruit infestation under artificial light at night:light colour matters

Michiel P Boom,Arjen Biere,Eva Knop,Marcel E Visser,Kamiel Spoelstra

doi:10.1038/s41598-020-75471-1

Michiel P Boom, Arjen Biere + Show 3 more

Open Access

https://doi.org/10.1038/s41598-020-75471-1

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Abstract

Rapid human population growth and associated urbanization lead to increased artificial illumination of the environment. By changing the natural light–dark cycle, artificial lighting can affect the functioning of natural ecosystems. Many plants rely on insects in order to reproduce but these insects are known to be disturbed by artificial light. Therefore, plant–insect interactions may be affected when exposed to artificial illumination. These effects can potentially be reduced by using different light spectra than white light. We studied the effect of artificial lighting on plant–insect interactions in the Silene latifolia–Hadena bicruris system using a field set-up with four different light treatments: red, green, white and a dark control. We compared the proportion of fertilized flowers and fertilized ovules as well as the infestation of fruits by Hadena bicruris, a pollinating seed predator. We found no difference in the proportion of fertilized flowers among the treatments. The proportion of fruits infested by H. bicruris was however significantly higher under green and white light and a significantly lower proportion of fertilized ovules was found under green light. We show that artificial light with different colours impacts plant–insect interactions differently, with direct consequences for plant fitness.

Highlights

Rapid human population growth and associated urbanization lead to increased artificial illumination of the environment
We found that under artificial light at night there was no effect of light colour on the proportion of fertilized flowers but that there was a higher proportion of infestation under green and white light
Females of H. bicruris show no fatal attraction to light at short distances[21] and it may be attracted to these light sources from longer distances, but at closer distances ‘escapes’ from this attraction

Summary

Introduction

Rapid human population growth and associated urbanization lead to increased artificial illumination of the environment. Light at night can interfere with the activity and behaviour of nocturnal moths[7] and disrupt plant-pollinator interactions with negative consequences for pollination[8]. One way plant-pollinator interactions might be disrupted is distinct flight to light behaviour of many nocturnal insects[7,14,15], which can distract them from visiting the flowers. This attraction to artificial light is an important cause of mortality among flying insects[16,17] and can lead to reduction of moth population numbers[18]. This relation with wavelength might cascade to important ecosystem function of moths, such as pollination, remains largely unclear (but see Knop et al.[8])

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