Stonefly systematics: past, present, and future

Abstract

Stoneflies (Insecta: Plecoptera) are a widespread group of freshwater insects known for their ecological significance and sensitivity to environmental change. This diverse order encompasses over 4,000 species across 17 families, with the number of described species predicted to increase substantially over the coming years. This review surveys the past and present landscape of stonefly systematics, emphasizing recent advancements in our understanding of the phylogenetic relationships within this group to the ordinal, subordinal, and family level. We highlight the need for expanded biodiversity surveys, particularly in underexplored regions such as high-elevation ecosystems, the Southern Hemisphere, and the Arctic, and identify the key challenges impeding the advancement of systematic research, in particular the decline in taxonomic expertise. Looking forward, we outline a vision for the future of stonefly systematic research, advocating for increased inclusivity, collaborative research efforts, and the integration of advanced molecular methodologies.