Abstract
Artificial light at night (ALAN) is a growing threat to biodiversity and ecosystems globally. However, a limited number of studies have focused on the effect of ALAN in the tropical or subtropical regions, and the impact of ALAN on species interactions and ecological processes is particularly understudied. We introduced ALAN into light-naïve forest plots to examine whether ALAN affects herbivory rate and alters the growth and abundance of Nephila pilipes , a common orb-weaver spider. We found illuminated plots had a higher herbivory rate than control plots in the early wet season. The growth rate and abundance of the spider species, however, were not affected by ALAN. Our results indicate that ecological processes in tropical ecosystems, such as herbivory, are potentially sensitive to ALAN. Additionally, this study highlights the importance of a more mechanistic understanding of the sensitivities of tropical species interactions to ALAN and the possible complications caused by environmental variation.