Declining rates of species description call for improved taxonomic strategies: Insights from a megadiverse insect order

Abstract Classifying organisms is fundamental in biodiversity research, but time‐consuming. Although technological advances in species discovery and phylogenetic analysis have marked the early 21st century, we are far from achieving a comprehensive inventory of species diversity, as many taxa remain largely undocumented. Discovering or classifying lineages without formally describing and naming them leaves biodiversity knowledge incomplete and non‐interoperable, as such units cannot be consistently referenced or validated across datasets and disciplines. Accelerating formal species description therefore requires a strategic, data‐driven plan to maximize efforts with finite resources. Using a uniquely complete dataset, we explored past, current and projected trends in the description of the megadiverse yet largely understudied true flies (Insecta: Diptera). We found evidence of a persistent global decline in Diptera species descriptions since the late 1990s. At current rates, it will take centuries to describe even the well‐studied groups, which represent only a fraction of Diptera diversity. We argue that many other insect orders are in the same conditions, given the misalignment of research priorities, under‐utilization of emerging tools, the overall shortage of taxonomic expertise and the limited availability of curated data for neglected groups. To address these challenges, we propose five strategic priorities for a renewed, data‐integrative taxonomy aimed at accelerating the formal description of species, with potential applications across much of the remaining undocumented animal diversity.