More trees, more moths: how urban treescapes can help reverse moth declines

Richard Fox, Tomas Roslin, Emilie E Ellis 

Moths are undergoing widespread declines in abundance, biomass and diversity, with consequences for pollination, herbivory and trophic interactions. Yet moth conservation remains poorly integrated into biodiversity policy and practice, particularly in urban environments. Here, we argue that trees offer an underused, but very timely, opportunity to support urban moth communities. Trees provide larval hostplants, adult food resources, shelter, microclimatic buffering and connectivity, but their benefits depend on more than canopy cover alone. Evidence for how urban treescapes support moths remains limited. We therefore draw on studies from agricultural and forest landscapes, which show that moth communities depend on tree identity, age, structural complexity, sheltered habitat and landscape connectivity. These insights provide practical guidance for designing and managing urban treescapes for moth biodiversity. As humanity becomes increasingly urban, and climate change and pollution make cities less habitable, tree planting is already being expanded to provide cooling, cleaner air, and improved human wellbeing. Incorporating moth ecology into these existing, human-centred initiatives could deliver meaningful conservation gains without requiring new interventions. Selecting suitable tree species, retaining mature and structurally complex vegetation, protecting sheltered woodland cores and connecting parks, gardens, streets and woodland fragments could transform routine urban greening into a practical response to moth declines. Urban trees should therefore be treated not only as infrastructure for liveable, climate-resilient cities for humans, but also as ecological habitat capable of supporting diverse moth communities under intensifying anthropogenic pressures across multiple stages of their complex life cycles.