27.02.2019 | Reinhard Lässig | News WSL
The Asian long-horned beetle, a particularly dangerous insect according to the Ordinance on Plant Protection, which was detected in Brünisried in Canton Fribourg in 2011 and in Marly in 2014, was successfully eradicated after several years of control.
The Asian long-horned beetle is an insect originating from East Asia that infests healthy deciduous trees. It can inflict severe damage on them, including the death of the trees. For this reason, the beetle is classified as particularly dangerous in the Federal Ordinance on Plant Protection. The cantons are obliged to combat this insect in accordance with the federal eradication strategy.
The largest infestation of this insect species in Switzerland was discovered in Marly in 2014. In close cooperation with the municipality of Marly, the Federal Office for the Environment (FOEN) and the Swiss Federal Institute for Forest, Snow and Landscape Research WSL, the canton of Fribourg took strict measures, such as felling numerous trees and carrying out intensive checks on remaining trees. These checks were undertaken by tree climbers and specially trained sniffer dogs.
Successful fight against the Asian long-horned beetle
The measures proved to be extremely efficient, as there have been no further signs of infestation since 2014. For an infestation to be considered eradicated, intensive checks must be carried out over a period of four years in accordance with the federal government's instructions, without there being any indication of a new presence of the beetle.
Another infested area of lesser extent was discovered in Brünisried FR in 2011 and classified as extinct at the end of 2017. As it turned out in 2014, this infestation was related to the one in Marly, as infested wood had been transported from Marly in 2011 or earlier to Brünisried before the infestations were known.
The controls will now be completed at both locations, and the infestation site in Marly is considered officially eradicated since the end of 2018. The preventive measures (ban on wood transports, compulsory chipping, planting restrictions, etc.) introduced by a cantonal ordinance will be lifted immediately. There is currently no known infestation area of the Asian long-horned beetle in the canton of Fribourg.
The external costs borne by the State of Fribourg amount to CHF 2 390 100 for Marly and CHF 234 380 for Brünisried, i.e. a total of CHF 2 624 480. Thanks to the amendment of the Federal Forestry Act and because protective forest was located in the control area, the Confederation was able to contribute to the costs. The net cost after deduction of federal subsidies is CHF 1 658 754.
One of the success factors was the good cooperation between the canton, the population and the partner institutions mentioned above. In dealing with this extraordinary situation, numerous findings have been gained which can also be of use in other infested areas in Switzerland as well as abroad and which have been incorporated into the FOEN's forest protection implementation aid.
To thank the inhabitants of Marly for their good cooperation, the canton offers to the owners of plots in the "core zone" (where the trees have been felled) who so wish, a fruit tree planted free of charge. The persons concerned will receive further information in a letter, in the municipal newspaper and on the municipal website.
The tasks of the Swiss Federal Research Station WSL include to clearly identify the beetles at all stages of their development and to provide expert advice and support throughout the entire monitoring period. WSL also provided its partners at the federal government, cantons, municipalities and participating freelance experts with prepared demonstration and test material for public relations and sniffer dog work and conducted training courses. In addition, age investigations of the beetle infestation and genetic analyses were carried out. Thus the connection between the infestation in Marly and the find in Brünisried was confirmed.