Tag: DNA barcoding

A genus of European paper wasps revised for the first time using integrative taxonomy

The European and Mediterranean species of the paper wasp genus Polistes were recently revised by scientists at the SNSB-Zoologische Staatssammlung München (ZSM).

For the first time for this group scientists applied an integrative taxonomic approach which combines traditional morphological methods with modern DNA barcoding.

As a result, the researchers were able to identify a new species from Morocco. For this well-researched wasp group, this is an actual sensation.

The study is published in the open access journal ZooKeys.

The Munich researchers analysed more than 260 wasp specimens collected from across the study area with the help of DNA barcoding.

They managed to identify all species and determine their distribution. In addition, based on the genetic data, they were able to evaluate morphological characters for each species and created a completely new key for identification.

The wasps of the genus Polistes belong to the family Vespidae. The genus is represented by 17 species in Europe and the Mediterranean, with four species occurring in Germany. Within the genus, 13 species are social, with the queen overwintering and founding a new nest with up to 200 workers. Four species are parasitic and have no workers.

Although Polistes has been well-known in Central Europe for more than 200 years, knowledge of Mediterranean species has so far been scarce. Many species of the genus exhibit only subtle morphological differences and show high levels of colour variation, further complicating their identification.

An important result of this research is the separation of species of the Polistes gallicus species complex into three distinct species. Moreover, the genetic data led to the discovery of a new species, represented by a single specimen from the High Atlas Mountains in Morocco. This was an unexpected result for the researchers. The species was named Polistes maroccanus.

Another very surprising result was the discovery of high levels of genetic variation within Polistes dominula, a species commonly found in Central Europe, indicating the presence of up to three different and hitherto unrecognized species – a case requiring further investigation.

Integrative taxonomy is an approach that combines different scientific methods to reliably differentiate species. In particular, DNA barcoding has proven to be a useful technique for the identification of species and for the discovery of new species. The method allows to identify most species quickly and accurately, even those species that are difficult to identify using traditional methods based on morphological characters.

DNA barcoding uses a short gene fragment that differs in almost all species worldwide. The sequences are stored in an online database and can be used for identification. The method derives its name for being reminiscent of the barcodes similar to those found on products in supermarkets that allow quick and error-free identification at the checkout.

DNA barcoding is part of a global research initiative led by the Canadian scientist Paul Hebert from the University of Guelph. The ZSM is a project partner and involved in assembling DNA barcodes of the German animal species. In addition to ZSM researchers, scientists from Switzerland and the Netherlands contributed to the Polistes project.

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Original source:

Schmid-Egger C, van Achterberg K, Neumeyer R, Morinière J, Schmidt S (2017) Revision of the West Palaearctic Polistes Latreille, with the descriptions of two species – an integrative approach using morphology and DNA barcodes (Hymenoptera, Vespidae). ZooKeys 713: 53-112. https://doi.org/10.3897/zookeys.713.11335

Efficiency of insect biodiversity monitoring via Malaise trap samples and DNA barcoding

The massive decline of over 75% insect biomass reported from Germany between 1989 and 2013 by expert citizen scientists proves the urgent need for new methods and standards for fast and wide-scale biodiversity assessments. If we cannot understand species composition, as well as their diversity patterns and reasons behind them, we will fail not only to predict changes, but also to take timely and adequate measures before species go extinct.

An international team of scientists belonging to the largest and connected DNA barcoding initiatives (iBOL, GBOL, BFB), evaluated the use of DNA barcode analysis applied to large samples collected with Malaise traps as a method to rapidly assess the arthropod fauna at two sites in Germany between May and September.

One Malaise trap (tent-like structure designed to catch flying insects by attracting them to its walls and then funneling them into a collecting bottle) was set in Germany’s largest terrestrial protected natural reserve Nationalpark Bayerischer Wald in Bavaria. Located in southeast Germany, from a habitat perspective, the park is basically a natural forest. The second trap was set up in western Germany adjacent to the Middle River Rhine Valley, located some 485 kilometers away from the first location. Here, the vegetation is eradicated annually due to St. Martin’s fires, which occur every November. Their findings are published in the open access Biodiversity Data Journal.

DNA barcoding enables the identification of a collected specimen by comparing its BIN (Barcode Index Number) against the BOLD database. In contrast to evaluation using traditional morphological approaches, this method takes significantly less experience, time and effort, so that science can easily save up on decades of professional work.

However, having analyzed DNA barcodes for 37,274 specimens equal to 5,301 different BINs (i.e., species hypotheses), the entomologists managed to assign unambiguous species names to 35% of the BINs, which pointed to the biggest problem with DNA barcoding for large-scale insect inventories today, namely insufficient coverage of DNA barcodes for Diptera (flies and gnats) and Hymenoptera (bees and wasps) and allied groups. As the coverage of the reference database for butterflies and beetles is good, the authors showcase how efficient the workflow for the semi-automated identification of large sample sizes to species and genus level could be.

In conclusion, the scientists note that DNA barcoding approaches applied to large-scale samplings collected with Malaise traps could help in providing crucial knowledge of the insect biodiversity and its dynamics. They also invite their fellow entomologists to take part and help filling the gaps in the reference library. The authors also welcome taxonomic experts to make use of the unidentified specimens they collected in the study, but also point out that taxonomic decisions based on BIN membership need to be made within a comparative context, “ideally including morphological data and also additional, independent genetic markers”. Otherwise, the grounds for the decision have to be clearly indicated.

The study is conducted as part of the collaborative Global Malaise Trap Program (GMTP), which involves more than 30 international partners. The aim is to provide an overview of arthropod diversity by coupling the large-scale deployment of Malaise traps with the use of specimen-based DNA barcoding to assess species diversity.

Sequence analyses were partially defrayed by funding from the government of Canada through Genome Canada and the Ontario Genomics Institute in support of the International Barcode of Life project. The German Barcode of Life project (GBOL) is generously supported by a grant from the German Federal Ministry of Education and Research (FKZ 01LI1101 and 01LI1501) and the Barcoding Fauna Bavarica project (BFB) was supported by a 10-year grant from the Bavarian Ministry of Education, Culture, Research and Art.

Original source:

Geiger M, Moriniere J, Hausmann A, Haszprunar G, Wägele W, Hebert P, Rulik B (2016) Testing the Global Malaise Trap Program – How well does the current barcode reference library identify flying insects in Germany? Biodiversity Data Journal 4: e10671. https://doi.org/10.3897/BDJ.4.e10671

Surprising exotic flies in the backyard: New gnat species from Museum Koenig’s garden

Little did scientists Kai Heller and Björn Rulik expect to discover a new species in Germany’s Alexander Koenig Museum‘s garden upon placing a malaise trap for testing purposes. Not only did an unknown and strikingly coloured gnat get caught, but it turned out to be a species, which showed to have much more in common with its relatives from New Zealand. Their study is published in the open access Biodiversity Data Journal (BDJ).

While the genus, which the new dark-winged fungus gnat species belongs to, likely originates from the Australasian region, it was so far represented by only three species in Europe. None of them, however, stands out with the contrasting colouration of the presently announced fourth one.

The new gnat, called Ctenosciara alexanderkoenigi after the German museum’s founder, is described based on a single specimen caught in the framework of the German Barcode of Life Project (GBOL). Over three days, the scientists observed the flying insects getting caught in a malaise trap, placed among the predominantly non-native plants in the Alexander Koenig Museum’s garden. This tent-like structure is designed to catch flying insects. Once they fly into its walls, they get funnelled into a collecting bottle.

Upon noticing the beautiful striking colour of the fly, the two specialists were convinced they had just discovered a new to science species. Most of these flies are bright brownish, and the only other orange European dark-winged fungus gnat – almost uniformly orange. In contrast, the new species stands out with a mixture of reddish, black and yellowish-white hues. Based on the DNA-barcode match with New Zealand specimens, the authors concluded that the species must have arrived from the Australasian region in Europe quite recently.

“It is a rare occurrence, that a species from the opposite end of the world is represented by a single specimen only and it is not yet clear, whether Ctenosciara alexanderkoenigi has a permanent population in Germany or if it was only introduced casually with plants or soil,” they explain. “Probably, the species was recently introduced from the Australasian Region. If it was a permanent member of the European fauna, a striking species like this would likely have been found earlier.”

In conclusion, the scientists note that modern technologies such as the high quality photo documentation, established as a standard by the BOLD project, DNA barcodes assigned with BINs, as well as facilitated by speedy publishing, have largely aided taxonomists to build on the biodiversity knowledge.

“We believe that the rapid description of Ctenosciara alexanderkoenigi, coupled with the BDJ reviewing system, might be a robust and ground-breaking way to accelerate and stabilise taxonomy in the future,” they finish their paper.

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Original source:

Heller K & Rulik B (2016) Ctenosciara alexanderkoenigi sp. n. (Diptera: Sciaridae), an exotic invader in Germany? Biodiversity Data Journal 4: e6460. doi: 10.3897/BDJ.4.e6460