Unveiling the Global Linnean Shortfall in Leptophlebiidae (Ephemeroptera, Insecta): Historical Trends and Conservation Implications

Understanding how many species exist on Earth is a fundamental yet challenging question in biology, with significant implications for biodiversity conservation. The Linnean shortfall, or the gap in taxonomic knowledge, remains a major obstacle, particularly in highly diverse groups like insects. This study focuses on the family Leptophlebiidae (Ephemeroptera), analysing 267 years (1758–2025) of species and genus descriptions. Using historical data and predictive models, we quantified the global Linnean shortfall by estimating unknown genera and species richness and projecting discovery rates, providing insights into the pace of taxonomic progress and the critical role of taxonomists in this process. Our estimates suggest that 61% of Leptophlebiidae genera and 63% of species remain undescribed worldwide. These findings highlight a significant knowledge gap regarding the diversity of this family and underscore the urgent need to strengthen and direct taxonomic efforts to effectively inform conservation strategies.