a, b, c: Relationships between ID errors and taxon coverage of libraries.

<p>Overall ID errors ((FP+FN)/total number of queries) and relative ID errors (FP/number of not discarded queries) at 30 arbitrary BCM distance thresholds in a) Diptera, b) Lepidoptera and c) Hymenoptera. In the 100% taxon coverage simulation, each query had at least a conspecific in the reference database. In the remaining simulations 25%, 50% and 75% of query species were not represented in the reference library (corresponding to 75%, 50% and 25% of taxon coverage). Simulations of 75%, 50% and 25% taxon coverage were repeated three times (standard errors as error bars). For each simulation, <i>ad hoc</i> distance thresholds (THR_{K2P_0.05}) corresponding to a relative ID error <0.05 were inferred from linear fitting.