Artificial Night Lighting Reduces Firefly (Coleoptera: Lampyridae) Occurrence in Sorocaba, Brazil

Abstract

Artificial night lighting is gaining attention as a new type of pollution; however, studies of its impacts are scarce. Fireflies provide good models to investigate its effects on nocturnal wildlife, since they depend on their bioluminescence for reproduction. This study investigated the impact of artificial illumination on firefly activity at the new campus of the Federal University of São Carlos (Sorocaba, Brazil). The flashing activity of different firefly species, especially Photinus sp1 (82% of all occurrences), was investigated during 3 years, before and after the installation of multi metal vapor spotlights. Quantitative and qualitative analysis, performed in transects at different distances from the artificial light sources, showed significant negative effects on Photinus sp1 occurrence. This study proposes fireflies as potential flagship species and bioindicators for artificial night lighting and for the first time quantifies its effects, providing subsidies for future conservationist legislations regarding photopollution.