Number of nests Asian hornet in Flanders more than tripled
© Stefaan Beel
The number of reported nests of Asian horners in Flanders has tripled. This is evident on Friday from figures from the Vespa-Watch Reporting Center. Due to the mild winter and the warm spring, experts fear that the nuisance caused by the invasive exot this year can reach a peak.
In 2024 in Flanders in March and April – up to and including the eighteenth of the month – a total of 200 nests of the Asian hornet were reported to Vespa -Watch. In the same period this year there are already 636. In other words: there are already more than three times as many.
That strong increase is in line with the number of spotted queens via the Obsidentify app. On Thursday it turned out that the number of spotted horners throughout Belgium has almost doubled from 4,490 to 7,873 this year. Obsidentify is an initiative of Natuurvereniging Natuurpunt, among others, and has around 1 million users throughout the country, not just in Flanders.
The high number of nests in Flanders so early in the year is remarkable because not every queen who flies out after hibernation also effectively builds a nest. It is estimated that more than 90 percent die. It is therefore possible to underestimate the population.
« It is still unclear how strong the increase will be for this year, » says Jasmijn Hillaert, researcher for the Flemish Institute for Nature and Forest Research (Inbo). If the weather changes, the number of nests can still decrease. « Sunny and dry weather are ideal conditions for paper wasps, including the Asian hornet. That can result in more and larger nests. Last year, spring was exceptionally poor, which caused nature to get going slower. »
The horners are not only with more, but also stronger. According to Vespa-Watch, the caught specimens weigh considerably more, which increases that they will effectively build a nest. Each Nest produces an estimated 250 to 500 new queens.
In 2016, for the first time a nest of the Asian hornet appeared in our country. Since then, the exotic has been on the rise over the entire territory. In 2023, the Flemish government stated that the species has become too numerous to completely eradicate.
Asian hornets are basically not more aggressive than a normal wasp. If they feel threatened, they can attack in group, which can be dangerous. The rise of the invasive exotic is mainly disastrous for the honeybee, one of their favorite prey.
