CR2025_26 Impacts of light pollution, and other drivers, on UK moth communities and associated plant pollination

Lead Supervisor: Simon Potts, Department of Sustainable Land Management, University of Reading

Email: s.g.potts@reading.ac.uk

Co-supervisors: Mike Garratt, Department of Sustainable Land Management, University of Reading; Alberto Zilli, Natural History Museum; Ian Barnes, Natural History Museum; Richard Fox, Butterfly Conservation

Moths are under-researched organisms within the wider pollinator community and their role as crop and wildflower pollinators has recently been revealed to be much greater than previously thought (Potts et al. 2016). Historic and current drivers of moth community trends are poorly understood and light pollution is fast emerging as having a significant negative impact on nocturnal species (Barentine 2023). New evidence shows diverse impacts of artificial light across most life stages and key behaviours of moths (Boyes et al. 2021), with light pollution reducing nocturnal pollinator visits to flowers by 62% (Knop et al. 2017). This PhD will help address key evidence gaps to provide critical scientific insights to better inform policy and practices to safeguard pollinating moths.

The overarching aim of this study is to improve understanding of the threats posed by light pollution and other drivers on moth communities, individual foraging behaviours and pollination of UK crops and wild  plants. The specific objectives are: (1) to use the extensive NHM moth collections to reveal historical trends in UK moth communities, shifts in individual species traits (e.g. eye size), and pollen transport in relation to changing environmental pressures including land use change, climate change and light pollution; (2) to quantify the impacts of different types and levels of light pollution on the nocturnal foraging behaviour and pollination effectiveness of moths on wild plants and crops; and (3) to model the changes in moth communities and pollination under predicted future light pollution.

To understand historical and current trends of moths and pollination, we will use the NHM’s unique moth collections (~700,000 UK specimens), world leading DNA barcoding facilities, microscopy and (possibly) applicable electrochemical spectroscopic methods, to assess changes in moth communities at different UK locations through time, and to characterise the diversity of pollen loads from specimens. Collaboration with experts from Butterfly Conservation (the UKs leading Lepidoptera conservation NGO) will ensure access to 43 million historical moth records to inform on species and sites to study. Sites with long sequences of historical moth records will be re-surveyed to provide a contemporary snapshot of moth community composition and pollen loads, so that current and historical moth-plant visitation networks can be constructed and analysed.

To quantify the relative contributions of environmental drivers of shifts in moth communities, light pollution maps will be developed using historical land use maps with urban land use and road density as a proxy of intensity. Time points with important shifts in light sources (e.g. switch form sodium to LED lights) will be considered. Light pollution maps will be analysed in combination with existing spatial layers (e.g. UKCEH land use) including historic land use change and climate to partition out their relative contributions to shifts in moth populations.

The project will include experimental assessment of light pollution on foraging behaviour using Europe’s leading pollinator flight cages at the University of Reading (e.g. Stanley et al. 2015). Captive moth populations (e.g. Hadena, Lacanobia, Sideridis, Hecatera species) will be exposed to different intensities and spectra of artificial light, and skyglow, to measure impacts on their nocturnal foraging, pollen deposition and ultimately fruit and seed production of wildflowers (e.g. bramble) and crops (e.g. strawberry, Fijen et al. 2023).

This studentship combines cutting-edge approaches in quantitative ecology, empirical pollination biology, DNA barcoding, spatial modelling and statistics to address several outstanding questions on the status and trends of UK moths and the pollination services they provide. The University of Reading is an established world leader in pollinator and pollination research, and the NHM hosts some of the world’s most important collections and leading moth experts, as well as having state-of-the-art molecular facilities. The project will also benefit from Butterfly Conservation’s expertise and data within the supervisory team.

The project will provide the first quantitative assessment of the historical impacts of light pollution on UK moths and their flower visiting behaviour, and determine the impacts of different light regimes on crop production and wildflower reproduction. Findings will be used to inform recommendations for Defra, Natural England and other stakeholders, who have been engaged in the development of this project.

Training opportunities:

The student will benefit from high quality training across several disciplines including spatial modelling, GIS, network analysis and pollination fieldwork (Reading), as well as DNA barcoding and insect taxonomy (NHM). The student will have access to world-leading pollinator researchers through several European projects (e.g. Safeguard) led by Reading University. A placement is planned for the student with Defra’s Biodiversity Targets team (Reading and Butterfly Conservation sit on Defra’s Pollinator Advisory Steering Group) to  provide insights into how policy makers use evidence. The student will also gain experience of evidence use in conservation planning through engagement with Butterfly Conservation staff. 

Student profile: 

This project would be suitable for students with strong quantitative skills and a degree in biology, ecology or environmental science or a closely related subject. 

Co-Sponsorship details:

The project will receive co-sponsorship from Butterfly Conservation and include a placement with Defra’s Biodiversity Target team.

References:

• Barentine J. (2023) Artificial Light at Night: State of the Science
• Boyes et al. (2021) Is light pollution driving moth population declines? A review of causal mechanisms across the life cycle. Insect Conservation and Diversity 14: 167-187.
• Fijen et al. (2023) Nocturnal pollination is equally important as, and complementary to, diurnal pollination for strawberry fruit production. Agriculture, Ecosystems & Environment 350: 108475
• Knop et al. (2017) Artificial light at night as a new threat to pollination. Nature 548: 206–209
• Potts et al. (2016) Safeguarding pollinators and their values to human well-being. Nature 540: 220-229
• Stanley et al. (2015) Neonicotinoid pesticide exposure impairs crop pollination services delivered by bumblebees. Nature 528: 548-550