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

Foreign beetle species recorded for the first time in Canada thanks to citizen science

With social networks abound, it is no wonder that there is an online space where almost anyone can upload a photo and report a sighting of an insect. Identified or not, such public records can turn out to be especially useful — as in the case of an Old World beetle species — which appears to have recently entered Canada, and was recently discovered with the help of the BugGuide online portal and its large citizen scientist community.

Having identified the non-native rove beetle species Ocypus nitens in Ontario, Canada, based on a single specimen, author Dr Adam Brunke, affiliated with the Canadian National Collection of Insects, Arachnids and Nematodes, Ottawa, sought additional data to confirm his discovery.

Eventually, he found them in the citizen-generated North American digital insect collection BugGuide, created and curated by an online community of naturalists, insect enthusiasts and entomologists. After he verified as many as 26 digital photographs to be records of the same species, he concluded that the rove beetle has expanded its distribution to two new locations — Ontario, its first in Canada, and the state of Vermont, USA. His study is published in the open access Biodiversity Data Journal.

The species O. nitens is a fairly large rove beetle measuring between 12 and 20 mm in length and visibly distinguished by the characteristic form of the head and relatively short forewings. Furthermore, the insect is quite easy to spot because it prefers living around humans, often being spotted in woodlots and backyards.

As a result of the hundreds of years of Transatlantic trade, many species have been transported accidentally among various produce to subsequently adapt and establish on the other side of the ocean. While the rove beetle species O. nitens was first reported from the Americas in 1944, it was not until the turn of the new millennium that it escaped the small area in New England, USA, which had so far been its only habitat on the continent. Then, its distributional range began to rapidly expand. It is unlikely that the presence of this rove beetle, especially in Ontario, has long remained undetected, because of thorough and multiple sampling initiatives undertaken by professionals and students in the past.

The effect of the newly recorded species on the native rove beetles is still unknown. On the other hand, there are observations that several related beetles have experienced a drop in their populations in comparison to the records from the beginning of the century.

“Citizen-generated distributional data continues to be a valuable ally in the detection of adventive insects and the study of their distributional dynamics,” concludes the author.

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Original source:

Brunke A (2016) First detection of the adventive large rove beetle Ocypus nitens (Schrank) in Canada and an update of its Nearctic distribution using data generated by the public. Biodiversity Data Journal 4: e11012. https://doi.org/10.3897/BDJ.4.e11012

Being systematic about the unknown: Grid-based schemes could improve butterfly monitoring

Butterfly monitoring schemes are at the heart of citizen science, with the general public and researchers collaborating to discover how butterfly populations change over time. To develop the concept further, a new paper in the journal Nature Conservation shows how systematically placed, grid-based transects can help schemes by reducing habitat bias.

Rapidly increasing in number and popularity, Butterfly Monitoring Schemes have proved to be a method generating important, high-resolution data. Reliant on enthusiastic volunteers, who record butterflies along freely chosen transects, the collected observations are then used to explore and understand trends in butterfly numbers and distributions.

However, there is a risk associated with free site selection: some habitats can become underrepresented and monitoring results therefore less general than intended.

Butterfly hot-spots, such as semi-natural grasslands, tend to be favoured over less well-known environments. This means that butterflies living in other ‘less popular’ habitats, such as forests and wetlands, are covered less thoroughly and population declines of these species risk going undetected.

A team of Swedish researchers have now investigated the potential of a new, complimentary grid-based design, where butterfly recorders are to walk systematically placed transects across the country.

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The results of testing the new method showed that butterflies were abundant in traditionally overlooked habitats such as coniferous forests, bogs, and clear-cuts. Additionally, the systematic transects also performed well in avoiding habitat bias.

“Butterfly Monitoring Schemes are likely to benefit from adding grid-based butterfly transects as a complement to free site choice designs,” explains Dr. Lars B. Pettersson from Lund University. “Free and systematic site selection should not be seen as mutually exclusive, instead they can be used together to ensure high quality and inclusiveness of data for better assessing of future biodiversity trends.”

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Additional information:

This work has been carried out within the EU project STEP (FP7 grant 244090-STEP-CP-FP) and the Swedish Butterfly Monitoring Scheme (Swedish EPA contract 2227-13-003). It is part of the strategic research area Biodiversity and Ecosystems in a Changing Climate, BECC.

Undergraduate student takes to Twitter to expose illegal release of alien fish in Japan

Posing a significant threat to the native biodiversity in Japan, specifically that of threatened aquatic insects, some alien fishes, such as the bluegill, have become the reason for strict prohibitions. All activities potentially capable of introducing the species into the wild are currently punishable by either a fine of up to 3 million yen for a person (100 million yen for corporations), or a prison sentence of up to 3 years.

Recently, ten years after the law has been adopted, illegal release of bluegill fish has been reported for the first time with the help of a post on Twitter from Akinori Teramura, undergraduate student at the Tokyo University of Marine Science and Technology and second author of the present study. The case is reported and discussed by him and two scientists, affiliated with Kanagawa Prefectural Museum of Natural History, Japan, in the open-access journal ZooKeys.

In June 2015, Akinori Teramura tweeted two photographs of the invasive bluegill fish, both adults and juveniles, along with two young goldfish, which do not belong to the local fauna, either. In his post he identified the species and shared his surprise at the irresponsibility of the people who had released the fish. When lead author Dr Yusuke Miyazaki saw the tweet, he signalled his colleagues with the idea to publish the information as a scientific report.

The student found them in an outdoor public pool in Yokohama city, Japan, while it was being cleaned before being opened ahead of the summer. Usually, these facilities are closed to the public during the colder seasons and it is then when native aquatic insect species, such as dragonflies and diving beetles, find spawning and nursery habitats in them. Curiously enough, though, the pool had been isolated from natural waters since its construction.

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Therefore, the researchers conclude that the alien fishes have most likely been released from an aquarium from a local shop or an aquarist who no longer wanted them. However, the authors note that according to the law, keeping bluegill fish in a home aquarium is illegal as well.

“Our report demonstrates an example of web data mining in the discipline of Citizen Science,” say the authors. “Web data mining has been rapidly developing over recent years, and its potential continues to expand.”

“Community awareness of this issue needs to be improved, and widespread reporting of cases such as this one will help,” they conclude.

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Original source:

 

Miyazaki Y, Teramura A, Senou H (2016) Biodiversity data mining from Argus-eyed citizens: the first illegal introduction record of Lepomis macrochirus macrochirus Rafinesque, 1819 in Japan based on Twitter information. ZooKeys 569: 123-133. doi: 10.3897/zookeys.569.7577

Flickr and a citizen science website help in recording a sawfly species range expansion

Social network Flickr and citizen science website BugGuide have helped scientists to expand the known range of a rarely collected parasitic woodwasp, native to the eastern United States. Partially thanks to the two online photograph platforms, now the species’ distribution now stretches hundreds of miles west of previous records. Previously known from only 50 specimens mainly from the Northeast, now the species was discovered in the Ozark Mountains by researchers from the University of Arkansas. Their study is published it in the open access journal Biodiversity Data Journal.

Spurred on by the find, Michael Skvarla, a Ph.D. candidate at the university, contacted retired sawfly expert David Smith who alerted him to a hundred unpublished specimens housed in the United States National Entomology Collection at the Smithsonian, many of which were collected as bycatch in surveys that targeted invasive species like emerald ash borer andAsian longhorned beetle. Additional specimens from Iowa, Minnesota, and Manitoba, which also represent significant western range expansions, were found after users posted photos of the species on the social network Flickr and the citizen science website BugGuide.

“We used two resources – photos on social media and bycatch from large trapping surveys – which are often underutilized and I was really happy we could work both of them into the paper,” said Skvarla, the lead author. “This work highlights their utility, as well as the importance of maintaining biological collections like the U.S. National Collection and continuing to collect in undersampled regions like the Ozark Mountains.”

Parasitic woodwasps attack the immature stages of longhorned beetles, jewel beetles, and other woodwasps which bore into wood and have long fascinated entomologists because of this parasitoid nature, which is unique among woodwasps, and rarity in collections. The Arkansas specimens, which belong to the species Orussus minutus and motivated the initial research into the group, were collected as part of a larger survey of the insect fauna around the Buffalo National River.

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Original Source:

Skvarla, M.J., Tripodi, A., Szalanski, A., Dowling, A.P.G. 2015. New records of Orussus minutusMiddlekauff, 1983 (Hymenoptera: Orussidae) represent a significant western range expansion. Biodiversity Data Journal, 3: e35793. doi: 10.3897/BDJ.3.e5793