How a new laboratory method saves trees

The video contrasts two diagnostic methods of the Asian long-horned beetle Anoplophora glabripennis (ALB) that were conducted to find out, if the damage of the tree was caused by ALB or by a native beetle species (in this case the goat moth (Cossus cossus)). With the old method, the tree suspected of being infested with ALB had to be felled (destructive sampling) in order to extract the larvae for genetic analysis. With the novel diagnostic tool “frass analysis method” however, only the frass of the larvae is needed for the analysis (Becker et al. 2020). Thus, the biggest advantage of the new method is that trees no longer have to be felled for the analysis and can be spared, if the test result is negative (falsification of the suspicion). If the test result is positive and thus the suspicion is verified, the responsible authority orders measures that have to be carried out to eradicate the quarantine pest ALB. In the video, short images of the procedure of the “frass analysis method” are shown. First, DNA must be isolated from the larval frass sample. In a next step, species-specific primers are added to the sample to multiplicate potentially existing ALB DNA-fragments. All the other DNA fragments remain at low level in the sample. If there are ALB-specific DNA fragments in the sample and multiplication takes place, the curve on the output graph increases. To assure that the analysis works correctly, some control samples for comparison are run as well (i.a. positive controls that contain ALB DNA). Since the sample curve remains at a low level, it can be concluded that the test result is negative. Fortunately, the DNA is from a native species and no further action is needed. This molecular method is a suitable early warning system in the control of quarantine insect pests like ALB.
ALB is a quarantine pest in many countries, e.g. in the European Union. That means that this pest is of potential economic importance, and that it is not present or not widely distributed and is being officially controlled. The structural weakening of trees caused by larvae activity within woody tissue poses a danger to pedestrians and vehicles from falling branches (EPPO, 2021). ALB originates from Asia and can be spread by international trade mainly with wood packing material (Schröder, 2014). In Germany, ALB has been detected several times on native tree species. The first time in Neukirchen/Inn near Passau in 2004, where it was successfully eradicated (JKI, 2020).

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Credits:
Actors: Anabel Ritter, Bernhard C. Schäfer
Camera: Silke Steinmöller, Bernhard C. Schäfer, Bastian Hess, Anabel Ritter,
Editor: Bastian Hess
Idea: Anabel Ritter, Bernhard C. Schäfer, Silke Steinmöller, Bastian Hess, Stephan König, Ruth Schaarschmidt, Irene Fischbeck
Pictures: Thomas Schröder, Stephanie Feltgen, Tobias Wille, Björn Hoppe

[myrskylanmyrsky]

Great video! Loved the dramatic interplay between Rimsky-Korsakov (bad) and Vivaldi (good).