DNA barcoding as a screening tool for cryptic diversity: an example from Caryocolum, with description of a new species (Lepidoptera, Gelechiidae)

Abstract

We explore the potential value of DNA barcode divergence for species delimitation in the genus Caryocolum Gregor & Povolný, 1954 (Lepidoptera, Gelechiidae), based on data from 44 European species (including 4 subspecies). Low intraspecific divergence of the DNA barcodes of the mtCOI (cytochrome c oxidase 1) gene and/or distinct barcode gaps to the nearest neighbor support species status for all examined nominal taxa. However, in 8 taxa we observed deep splits with a maximum intraspecific barcode divergence beyond a threshold of 3%, thus indicating possible cryptic diversity. The taxonomy of these taxa has to be re-assessed in the future. We investigated one such deep split in Caryocolum amaurella (Hering, 1924) and found it in congruence with yet unrecognized diagnostic morphological characters and specific host-plants. The integrative species delineation leads to the description of Caryocolum crypticum sp. n. from northern Italy, Switzerland and Greece. The new species and the hitherto intermixed closest relative C. amaurella are described in detail and adults and genitalia of both species are illustrated and a lectotype of C. amaurella is designated; a diagnostic comparison of the closely related C. iranicum Huemer, 1989, is added.

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

“…Lepidoptera, the most intensively studied order, is represented by more than 100 000 BINs on BOLD. Work on this group has demonstrated the efficacy of DNA barcoding in identifying known species (Wilson et al 2013;Dinca et al 2015) and in revealing cryptic species complexes (Burns et al 2008;Huemer et al 2014a). It has also shown that there is very limited geographic variation in barcode sequences in populations of most species, so increased geographic scale does not reduce the success of species identification (Lukhtanov et al 2009;Huemer et al 2014b, Candek andKuntner 2015).…”

Revision of the genus Megacraspedus Zeller, 1839, a challenging taxonomic tightrope of species delimitation (Lepidoptera, Gelechiidae)

“…Like other genera, only a single species of Megacraspedus , M.dolosellus , was considered in the aforementioned study, reflecting the general lack of molecular data and analysis at the generic level. The implementation of DNA barcoding has helped to reduce such shortcomings in the Gelechiidae for a few genera so far (Huemer and Hebert 2011, Huemer et al 2014) but restriction to the mitochondrial COI gene limits the value for phylogenetic analysis. Molecular studies at a generic level, based on a larger number of nuclear genes, are completely lacking, not least because of the limitation and quality of available voucher material and the general lack of resources.…”

“…Studies in Gelechiidae genera using DNA barcodes are exceptional and give a somewhat different picture. An analysis of 44 species of Caryocolum (Huemer et al 2014) resulted in a maximum intraspecific divergence from 0% in several species to 6.3%, and in six species the mean divergence was greater than 3%. However, most of these cases represent allopatric cryptic diversity (Huemer pers.…”

“…Organization of sufficient vouchers and type material proved particularly challenging for our revisionary plans but many primary types were studied for the first time since their initial description. In contrast to most of the foregoing revisions of European/Palearctic Gelechiidae we took advantage of molecular methods, in particular DNA barcoding, combined with extensive studies of external and internal adult morphology (Huemer and Hebert 2011, Huemer et al 2014). This resulted in the discovery of an unexpected layer of hitherto undescribed diversity in Megacraspedus , encompassing approximately half of the presently described fauna.…”

Aenictus hoelldobleri sp. n., a new species of the Aenictus ceylonicus group (Hymenoptera, Formicidae) from China, with a key to the Chinese members of the group

“…To avoid unnecessary synonyms it may be more appropriate to refrain from new descriptions of Aenictus species until male-worker combinations are better understood, for example by applying barcoding approaches (see e.g. Huemer et al 2014). Not describing new species causes, however, a different problem.…”