Assessing long‐term effects of artificial light at night on insects: what is missing and how to get there

• Published in: Insect conservation and diversity 2021-03, Vol.14 (2), p.260-270
• Main Authors: Kalinkat, Gregor, Grubisic, Maja, Jechow, Andreas, Grunsven, Roy H. A., Schroer, Sibylle, Hölker, Franz
• Format: Article
• Language: English
• Subjects: Artificial light at night; Biodiversity; Biomass; Climate change; Climate effects; Conservation biology; Entomology; insect declines; Light effects; light pollution; Light sources; Population decline; population trends
• ISSN: 1752-458X; 1752-4598
• DOI: 10.1111/icad.12482

Widespread and significant declines of insect population abundances and biomass are currently one of the most pressing issues in entomology, ecology and conservation biology. It has been suggested that artificial light at night is one major driver behind this trend. Recent advances in the gathering and analysis of long‐term data sets of insect population and biomass trends, however, have mostly focused on the effects of climate change and agricultural intensification. We posit here that adequate assessment of artificial night at light that would be required to evaluate its role as a driver of insect declines is far from trivial. Currently its implementation into entomological monitoring programmes and long‐running ecological experiments is hampered by several challenges that arise due to (i) its relatively late appearance as a biodiversity threat on the research agenda and (ii) the interdisciplinary nature of the research field where biologists, physicists and engineers still need to develop a set of standardised assessment methods that are both biologically meaningful and easy to implement. As more studies that address these challenges are urgently needed, this article aims to provide a short overview of the few existing studies that have attempted to investigate longer‐term effects of artificial light at night on insect populations. To improve the quality and relevance of studies addressing artificial light at night and its effect on insects, we present a set of best practise recommendations where this field needs to be heading in the coming years and how to achieve it. The garden tiger moth (Arctia caja) is a species particularly affected by light pollution. Photo credit: Marian Schut We provide an overview of existing studies that have assessed long‐term effects of artificial light at night (ALAN) on insect populations and communities Almost no study to date has combined repeated, multiple samplings per year over multiple seasons with continuously implemented adequate measurements of ALAN To improve this situation, we present a set of best practise recommendations for future studies assessing long‐term effects of ALAN on insect populations and communities