Observations concerning the sampling of Sciomyzidae (Diptera) in High Nature Value wet grassland habitats: caveats to consider

High Nature Value (HNV) farmland is increasingly important within Europe and effective sampling strategies that collect invertebrates in agricultural wet grassland are vital to gauge the biodiversity in these pockets of high species richness. One group of potential bioindicators of HNV farmland particularly suited to wet grasslands are the marsh or snail‐killing flies (Diptera: Sciomyzidae). Their relatively sedentary adult habit and terrestrial – aquatic habitats make them ideal for fine‐grain resolution of biodiversity within farms. In this short communication, we demonstrate that using Malaise trapping, emergence trapping and sweep‐netting in isolation can result in incomplete species lists in addition to which we relate capture efficacies of the methods employed with reference to previous studies and the biology of the species concerned. Furthermore, we demonstrate that sweep‐net captures are more effective at crepuscular periods (dawn and dusk) than during the middle of the day.