The Impact of Different Types of Artificial Lights on Nocturnal Pollination by Hawkmoths in Argentina: Insights for Urban Planning and Biodiversity Conservation

Martina Lourdes Tosatto

We are currently facing a global decline in pollinators, mainly linked to agricultural and urban expansion. In this context, artificial light at night (ALAN) has emerged as a growing environmental threat associated with urbanization. ALAN disrupts natural day-night cycles, affecting the physiology, behavior, and ecological interactions of insects, such as the nocturnal pollinators, hawkmoths (Lepidoptera: Sphingidae).

Lighting technologies affect nocturnal pollination differently depending on the spectral sensitivity of pollinators and light source spectra. Traditional technologies, such as mercury vapor lamps, attract insects and lead to their death by exhaustion or predation. In contrast, LED lights can reduce insect attraction if blue light emissions are minimized. However, LEDs also alter floral and foliar perception by hawkmoths, potentially affecting their pollination efficiency. As global cities transition to LED lighting, it is crucial to understand the ecological impacts of different technologies.

This project aims to evaluate how various lighting technologies affect hawkmoth-mediated nocturnal pollination. We will assess indicators of plant reproductive success (visitation frequency, pollen deposition, and fruit and seed set) across sites exposed to three light technologies: mercury vapor lamps or high-pressure sodium, LED lights, and natural darkness. Vegetation cover will also be measured as an indicator of habitat quality, which influences hawkmoth activity.

The project includes a citizen science initiative that engages the community in collecting data on public lighting in the province of Córdoba (Argentina) while raising awareness about the responsible use and ecological impact of ALAN. Participants will attend workshops on the topic and the data collection protocol. Using a mobile app, they will photograph the luminaires with a diffraction tool, and each image will be calibrated to identify the type of light source (mercury vapor, high-pressure sodium, or LED). In addition, informational brochures and social media dissemination will be developed to share information and encourage greater participation.

Finally, data from citizen science and pollination surveys will be used to create a vulnerability map showing the relationship between lighting technologies and nocturnal pollination. This map will highlight sensitive areas and the spatial distribution of artificial light sources. It will be shared with lighting manufacturers, public agencies, urban nature reserves, and civil organizations to inform the impact of different lighting technologies on sustainable urban planning and to guide reforestation in urban areas with low vegetation cover.

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