title: DNA Barcoding to Improve the Taxonomy of the Afrotropical Hoverflies (Insecta: Diptera: Syrphidae).
abstract: The identification of Afrotropical hoverflies is very difficult because of limited recent taxonomic revisions and the lack of comprehensive identification keys. In order to assist in their identification, and to improve the taxonomy of this group, we constructed a reference dataset of 513 COI barcodes of 90 of the more common nominal species from Ghana, Togo, Benin and Nigeria (W Africa) and added ten publically available COI barcodes from nine nominal Afrotropical species to this (total: 523 COI barcodes; 98 nominal species; 26 genera). The identification accuracy of this dataset was evaluated with three methods (K2P distance-based, Neighbor-Joining (NJ) / Maximum Likelihood (ML) analysis, and using SpeciesIdentifier). Results of the three methods were highly congruent and showed a high identification success. Nine species pairs showed a low (< 0.03) mean interspecific K2P distance that resulted in several incorrect identifications. A high (> 0.03) maximum intraspecific K2P distance was observed in eight species and barcodes of these species not always formed single clusters in the NJ / ML analayses which may indicate the occurrence of cryptic species. Optimal K2P thresholds to differentiate intra- from interspecific K2P divergence were highly different among the three subfamilies (Eristalinae: 0.037, Syrphinae: 0.06, Microdontinae: 0.007-0.02), and among the different general suggesting that optimal thresholds are better defined at the genus level. In addition to providing an alternative identification tool, our study indicates that DNA barcoding improves the taxonomy of Afrotropical hoverflies by selecting (groups of) taxa that deserve further taxonomic study, and by attributing the unknown sex to species for which only one of the sexes is known.
authors.affiliation: Department of Biology-Invertebrate Section and Joint Experimental Molecular Unit (JEMU), Royal Museum for Central Africa, Leuvensesteenweg 13, B-3080 Tervuren, Belgium.
authors.forename: Kurt
authors.initials: K
authors.lastname: Jordaens
authors.affiliation: Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
authors.forename: Georg
authors.initials: G
authors.lastname: Goergen
authors.affiliation: Department of Biology-Invertebrate Section and Joint Experimental Molecular Unit (JEMU), Royal Museum for Central Africa, Leuvensesteenweg 13, B-3080 Tervuren, Belgium.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Virgilio
authors.affiliation: International Institute of Tropical Agriculture, 08 BP 0932 Tri Postal, Cotonou, Republic of Benin; Royal Belgian Institute of Natural Sciences-OD Taxonomy and Phylogeny and Joint Experimental Molecular Unit (JEMU), Vautierstraat 29, B-1000 Brussels, Belgium.
authors.forename: Thierry
authors.initials: T
authors.lastname: Backeljau
authors.affiliation: Department of Biology-Invertebrate Section and Joint Experimental Molecular Unit (JEMU), Royal Museum for Central Africa, Leuvensesteenweg 13, B-3080 Tervuren, Belgium.
authors.forename: Audrey
authors.initials: A
authors.lastname: Vokaer
authors.affiliation: Department of Biology-Invertebrate Section and Joint Experimental Molecular Unit (JEMU), Royal Museum for Central Africa, Leuvensesteenweg 13, B-3080 Tervuren, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: De Meyer
mesh_terms: D000349:Africa; D000818:Animals; D001483:Base Sequence; D058893:DNA Barcoding, Taxonomic; D004175:Diptera / Q000145:classification* / Q000235:genetics*; D008969:Molecular Sequence Data