Identification of forensically important Sarcophaga species (Diptera: Sarcophagidae) using the mitochondrial COI gene

<p>The identification of species of the forensically important genus Sarcophaga is very difficult and requires strong taxonomic expertise. In this study we sequenced the mitochondrial cytochrome c oxidase subunit I gene (COI) of 126 specimens of 56 W European Sarcophaga species. As such we established the first COI database for West European Sarcophaga. We added existing data to our database to yield a total dataset of 270 COI sequences from 99 species to evaluate the COI gene as a molecular diagnostic tool for species identification in this genus. Using two simple criteria (Best Match and Best Close Match) we showed that the identification success using a mini-barcode region of 127 bp was very low (&lt;61%). The identification success using the standard barcode region (658 bp) or using the entire COI region (1535 bp) was similar but relatively low: 75-80%. This was mainly due to specimens that were only represented by a single sequence in the dataset. Omitting these species resulted in a strong increase of the identification success: 96.9-98.5%. This success was even further increased when applying a nucleotide-based analysis but the latter may not be suitable for decision making. Even though the COI gene seems suitable to discriminate among most Sarcophaga species, additional markers will be necessary to achieve a 100% identification success.</p>