DNA barcoding and the documentation of alien species establishment on sub-Antarctic Marion Island

Abstract

Invasive alien species constitute a substantial conservation challenge in the terrestrial sub-Antarctic. Management plans, for many of the islands in the region, call for the prevention, early detection, and management of such alien species. However, such management may be confounded by diYculties of identiWcation of immatures, especially of holometabolous insects. Here we show how a DNA barcoding approach has helped to overcome such a problem associated with the likely establishment of an alien moth species on Marion Island. The discovery of unidentiWable immatures of a noctuid moth species, 5 km from the research station, suggested that a new moth species had colonized the island. EVorts to identify the larvae by conventional means or by rearing to the adult stage failed. However, sequencing of 617 bp of the mitochondrial cytochrome oxidase subunit I gene, and comparison of the sequence data with sequences on GENBANK and the barcoding of life database enabled us to identify the species as Agrotis ipsilon (Hufnagel), a species of which adults had previously been found regularly at the research station. Discovery of immatures of this species, some distance from the research station, suggests that a population may have established. It is recommended that steps to be taken to eradicate the species from Marion Island.

DNA barcodes for bio-surveillance: regulated and economically important arthropod plant pests

“…Since DNA barcoding reliably identifies both immatures and adults (Shin et al 2013), and can differentiate introduced and native pests (Chown et al 2008), it has been used to help manage species complexes in agricultural systems (Li et al 2011;Frewin et al 2014). Such applications are important because insecticide resistance can vary between closely related species, and even between genotypes of the same species (van Toor et al 2008).…”

Are genetic databases sufficiently populated to detect non-indigenous species?

“…The latter often requires examination of mature specimens of a particular sex, or flowering or fruiting specimens for some plant species (Radford et al 1968;Cross et al 2010), which may or may not be present in initial collections of individuals from a new habitat. In contrast, molecular methods allow identification of NIS at any life stage, based on successful DNA extraction from a single individual, egg, or seed-possibly facilitating early detection of NIS before an introduced population becomes fully established in an area (Armstrong and Bell 2005;Chown et al 2008;Briski et al 2011;Zhan and MacIsaac 2015). Early identification of NIS, followed by immediate eradication before reproductive or flowering phases, may prevent distribution of eggs, seeds or pollen, circumventing the establishment of the next generation, admixture of genetic material among distinct NIS populations or hybridization with closely related species (Kolbe et al 2007;Ayres et al 2008;Cross et al 2010).…”

Impacts of biological invasions: what's what and the way forward

“…Early detection can be improved by innovative tools, such as monitoring for environmental DNA [50]. Molecular approaches are increasingly used to monitor invasions in vulnerable environments [51]. Early detection allows for cost-effective removal.…”