Species traits to guide moth conservation in anthropogenic regions: A multi‐species approach using distribution trends in Flanders (northern Belgium)

Abstract

Insect abundance and diversity appear to decline rapidly in recent decades, garnering significant media attention, and hence raising public awareness. Macro‐moths—a species‐rich and ecologically diverse insect group—face severe declines, particularly in urbanised and intensively farmed areas in NW Europe. Flanders is a highly anthropogenic region, serving as a case study where the impact on macro‐moths of stressors like intensive agriculture, industrialisation and urbanisation has been quantified through a recently compiled Red List. Here, for 717 macro‐moth species, we calculated relative changes in distribution area between a reference period (1980–2012) and the subsequent period (2013–2022). By correlating these species‐specific trends with 10 key ecological and life history traits, we calculated more general Multi‐Species Change Indices (MSCIs). These MSCIs showed that species associated with wet biotopes and heathlands declined on average by 20%–25%, while (sub)urban species increased by more than 60%. Species feeding on lichens or mosses increased by 31%, while grass‐feeding species decreased by 20%. Both very small (+34%) and very large species (+15%) increased, whereas medium‐sized species decreased by 5%. Monophagous (+17%), migrant (+88%) and colour‐invariable species (+5%) increased, while colour‐variable species decreased (−8%). Finally, Holarctic (−21%) and Palaearctic species (−5%) decreased, while Mediterranean (+27%) and Western‐Palaearctic species (+9%) increased. Our trait‐based approach identifies key threats and mitigation strategies for moths in anthropogenic regions, offering evidence‐based insights for crafting efficient management recommendations and informed conservation policies to safeguard moth communities.