The Asian hornet has spread strongly in Switzerland in the last year. The hornet originates from Southeast Asia and first arrived in Europe via transport routes in 2004. In 2017, it was observed in Switzerland for the first time. According to the Bee Health Service (BGD), the native honey bee is one of the Asian hornet's favorite prey. It accounts for up to 85 percent of their diet.

Strong spread

As the "Schweizerische Bienenzeitung" writes, the population of the Asian hornet spread strongly in Switzerland in 2022. In total, it was sighted at 24 sites in eight cantons. Numerous sightings have already been reported in 2023 as well. The "Bienenzeitung" cites the mild winter as the reason for the strong increase, which led to a particularly large number of young queens surviving and being able to establish nests in the spring.

Attention and professional control necessary

Under the leadership of the BGD, a task force was established in 2022 to detect and eliminate Asian hornet nests. The task force also trains the cantonal authorities to be able to detect the nests independently in the future. The Bee Newspaper describes a successful example of the detection and removal of a nest. It shows that in order to successfully combat the Asian hornet, there needs to be good cooperation between beekeepers, the cantonal authorities, the task force and also pest control companies that can professionally combat and dispose of the Asian hornet nests.

Since July 1, 2023, the general population can report sightings of Asian hornets on the Swiss Asian Hornet Reporting Platform. Observers can upload the location where they were found there, as well as a picture or video of the hornet. Traps should not be set, however, as live specimens are needed to find the nests. The Family Gardeners Association also calls on people to be vigilant and call for professional control. This uses sulfur dioxide as a pesticide, as can be seen from the recommendations for action that a working group around the FOEN and bee health service has produced.

Do not import illegal plants

The spread of the Asian hornet is another example of an invasive pest that poses a threat to native species. The Japanese beetle or cherry vinegar fly have also become a threat to native agriculture in recent years. But it's not just insects that pose problems for farmers. More and more invasive plants are also spreading in Switzerland and displacing the native flora, such as the "native professional weed", which is similar to chamomile. Up-to-date information and lists of these so-called neophytes are provided by infoflora.

Introduced plants can also transmit serious diseases. For example, the Federal Office for Agriculture warns against the bacterium Xylella fastidiosa (Xf), which is the most dangerous bacterium for plants worldwide. It has led to the emergency felling of thousands of olive trees in southern Europe. This is because one host plant is the olive tree. Therefore, when tourists return to Switzerland, they should avoid bringing in foreign plants, if possible, and certainly not plants on the quarantine list.

Plant protection products remain important

Globalization and the associated flow of goods increase the likelihood that certain invasive species will travel in luggage, containers or transport crates. This cannot be prevented. Therefore, in addition to the control measures described above, new biocides or plant protection products are always needed. This is illustrated by the example of the Japanese beetle, for which pesticides are used in addition to traps and collection.