DNA Taxonomy and the identification of immature insect stages: the true larva of Tauriphila argo (Hagen 1869) (Odonata: Anisoptera: Libellulidae)

For many insect taxa, larval morphology plays a decisive role in various fields like taxonomy, phylogeny or ecology. However, species identification is usually based on imaginal characters and the identification of larvae depends upon an established link to unequivocally identified imagines. This taxonomic correspondence of larvae and imagines is far from being established in many odonate species. We have employed a molecular approach to link larval and adult specimens in Tauriphila argo (Hagen, 1869). The sequenced mt SSU gene fragments of the reared female, supposedly a T. argo female, and a clearly identified male specimen of the species were identical. However, the larva of the reared female clearly differed from the described T. argo larva, previously matched to the species. From this observation, we conclude that the previously described larva of T. argo does not belong to this species because of too many phenotypic differences that far exceed the generally observed intraspecific variation.

It can be foreseen that the molecular approach will prove to be effective in identifying unknown larvae in many insect species. Additionally, the discrimination of sibling species or the linkage of allotypes and holotypes will become feasible with this approach.