Building-Up of a DNA Barcode Library for True Bugs (Insecta: Hemiptera: Heteroptera) of Germany Reveals Taxonomic Uncertainties and Surprises

Abstract

During the last few years, DNA barcoding has become an efficient method for the identification of species. In the case of insects, most published DNA barcoding studies focus on species of the Ephemeroptera, Trichoptera, Hymenoptera and especially Lepidoptera. In this study we test the efficiency of DNA barcoding for true bugs (Hemiptera: Heteroptera), an ecological and economical highly important as well as morphologically diverse insect taxon. As part of our study we analyzed DNA barcodes for 1742 specimens of 457 species, comprising 39 families of the Heteroptera. We found low nucleotide distances with a minimum pairwise K2P distance <2.2% within 21 species pairs (39 species). For ten of these species pairs (18 species), minimum pairwise distances were zero. In contrast to this, deep intraspecific sequence divergences with maximum pairwise distances >2.2% were detected for 16 traditionally recognized and valid species. With a successful identification rate of 91.5% (418 species) our study emphasizes the use of DNA barcodes for the identification of true bugs and represents an important step in building-up a comprehensive barcode library for true bugs in Germany and Central Europe as well. Our study also highlights the urgent necessity of taxonomic revisions for various taxa of the Heteroptera, with a special focus on various species of the Miridae. In this context we found evidence for on-going hybridization events within various taxonomically challenging genera (e.g. Nabis Latreille, 1802 (Nabidae), Lygus Hahn, 1833 (Miridae), Phytocoris Fallén, 1814 (Miridae)) as well as the putative existence of cryptic species (e.g. Aneurus avenius (Duffour, 1833) (Aradidae) or Orius niger (Wolff, 1811) (Anthocoridae)).

How to tackle the molecular species inventory for an industrialized nation—lessons from the first phase of the German Barcode of Life initiative GBOL (2012–2015)

“…Several scientific publications have resulted from the first phase of GBOL and the Barcoding Fauna Bavarica project, including, for example, the demonstration of extreme levels (up to 16.7% p-distance) of cryptic diversity in the centipede Stenotaenia linearis (Wesener et al 2015) or a widespread freshwater nematode morphospecies (Ristau et al 2013). Analyzing more than 400 species of true bugs, other colleagues showed that DNA barcodes are highly effective in distinguishing over 90% of Heteroptera species (Raupach et al 2014), and a similar high level of identification success was observed in neuropterids and Lepidoptera (Hausmann et al 2011a(Hausmann et al , 2011b. The release of the first comprehensive and largest DNA barcode reference library for Coleoptera included over 3500 species (53% of the German fauna), and again more than 90% of the specimens could be unambiguously identified via their DNA barcode (Hendrich et al 2015).…”

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

“…The use of barcode data to identify species (Rakauskas and Basilova 2013) as opposed to BINs requires the species in question be represented in the barcode reference library (Ekrem et al 2007). Because the barcode reference library now includes records for many agricultural and forestry pests (Ashfaq et al 2014;Foottit et al 2014;Raupach et al 2014), newly encountered specimens of these species can be identified through barcode analysis. As well, the extension of DNA barcoding protocols onto next-generation sequencing (NGS) platforms (Shokralla et al 2014) is enabling metabarcoding studies that permit large-scale assessments of species composition (Taberlet et al 2012), an approach of high importance in monitoring plant pests.…”

“…DNA barcoding has a strong track record in delivering species-level identifications for the five insect orders with the most pest species-Coleoptera (Woodcock et al 2013;Rougerie et al 2015), Diptera (Nagy et al 2013;Smit et al 2013), Hemiptera (Park et al 2011b;Raupach et al 2014), Lepidoptera (Janzen et al 2005;Ashfaq et al 2013), and Thysanoptera (Rebijith et al 2014;Iftikhar et al 2016). For example, 92.2% of 3514 species of European beetles were assigned to a distinct BIN that coincided with a known morphological species, while most of the other species were assigned to two or three BINs, suggesting they represent cryptic species complexes (Hendrich et al 2015).…”

Testing the Global Malaise Trap Program – How well does the current barcode reference library identify flying insects in Germany?

“…Based on a combination of genetic distance (2.2% ab initio ) and subsequent refinement using Markov clustering, it has proven extremely valuable in identifying specimens collected in large-scale biodiversity inventories (Aagaard et al 2016, Telfer et al 2015, Wirta et al 2015) and as an additional character for comparing traditional taxonomy concepts in, e.g. bees (Schmidt et al 2015), beetles (Oba et al 2015, Hendrich et al 2014), bugs (Raupach et al 2014), butterflies and moths (Hausmann et al 2013, Huemer et al 2014), fishes (Knebelsberger et al 2014a, Knebelsberger et al 2014b), Hemiptera (Gwiazdowski et al 2015), Neuroptera (Morinière et al 2014), and reptiles and amphibians (Hawlitschek et al 2015). Comparisons of the performance of the BIN system with other approaches for species delimitation (Kekkonen and Hebert 2014, Collins and Cruickshank 2014) indicated that it is superior in term of computational performance, but also that it might not work equally well in all animal groups, as for example illustrated in Tanytarsus nonbiting midges (Lin et al 2015).…”