Elbrecht V, Bourlat SJ, Hörren T, Lindner A, Mordente A, Noll NW, Schäffler L, Sorg M, Zizka VMA. 2021. Pooling size sorted Malaise trap fractions to maximize taxon recovery with metabarcoding. PeerJ 9:e12177 https://doi.org/10.7717/peerj.12177

Small and rare specimens can remain undetected when metabarcoding is applied on bulk samples with a high specimen size heterogeneity. This is especially critical for Malaise trap samples, where most of the biodiversity is contributed by small taxa with low biomass. The separation of samples in different size fractions for downstream analysis is one possibility to increase detection of small and rare taxa. However, experiments systematically testing different size sorting approaches and subsequent proportional pooling of fractions are lacking, but would provide important information for the optimization of metabarcoding protocols. We set out to find a size sorting strategy for Malaise trap samples that maximizes taxonomic recovery but remains scalable and time efficient.