Delineating species boundaries using an iterative taxonomic approach: The case of soldierless termites (Isoptera, Termitidae, Apicotermitinae)

Abstract

Species boundaries are traditionally inferred using morphological characters, although morphology sometimes fails to correctly delineate species. To overcome this limitation, researchers have widely taken advantage of alternative methods such as DNA barcoding or analysis of cuticular hydrocarbons (CHs) profiles, but rarely use them simultaneously in an iterative taxonomic approach. Here, we follow such an approach using morphology, DNA barcoding and CHs profiles to precisely discriminate species of soldierless termites, a diversified clade constituting about one-third of the Neotropical termite species richness, but poorly resolved taxonomically due to the paucity of useful characters. We sampled soldierless termites in various forest types of the Nouragues Nature Reserve, French Guiana. Our results show that morphological species determination generally matches DNA barcoding, which only suggests the existence of three cryptic species in the 31 morphological species. Among them, Longustitermes manni is the only species whose splitting is corroborated by ecological data, other widely distributed species being supported by DNA barcoding. On the contrary, although CHs profiles provide a certain taxonomic signal, they often suggest inconsistent groupings which are not supported by other methods. Overall, our data support DNA barcoding and morphology as two efficient methods to distinguish soldierless termite species.