DNA barcodes and morphology reveal a hybrid hawkmoth in Tahiti (Lepidoptera:Sphingidae)

Interspecific hybridisation is a rare but widespread phenomenon identified as a potential complicating factor for the identification of species through DNA barcoding. Hybrids can, however, also deceive morphology-based taxonomy, resulting in the description of invalid species based on hybrid specimens. As the result of an unexpected case of discordance between barcoding results and current morphology-based taxonomy, we discovered an example of such a hybrid ‘species’ in hawkmoths. By combining barcodes, morphology and a nuclear marker, we show that Gnathothlibus collardi Haxaire, 2002 is actually anF1hybrid between two closely related species that co-occur onTahiti. In accordancewith the International Code of Zoological Nomenclature, the taxon G. collardi is thus invalid as a species. This study demonstrates the potential of DNA barcodes to detect overlooked hybrid taxa. With the growth of sequence libraries, we anticipate that more unsuspected hybrid species will be detected, particularly among those taxa that are very rare, such as those known from only the type specimen. Additional keywords: 28S rDNA, COI, hybrid detection. Received 17 April 2012, accepted 13 September 2012, published online 19 December 2012