The Asian hornet (Vespa velutina) is almost impossible to stop. It is spreading inexorably across Europe. The insects prey on the local honey bee and also eat countless other insects. And they can even be dangerous to humans with their poison.
In Germany, the southwest is particularly affected. The State Environmental Agency in Baden-Württemberg has already reported 2,000 hornet nests this year, more than twice as many as last year. Beekeeper Achim Meinzer from the Karlsruhe Beekeepers Association accuses politicians of not doing enough to keep the Asian hornet in check.
“We will all pay if we don’t do more,” warns Meinzer. And Eckhard Richter from the Rhineland-Palatinate Beekeepers Association is also concerned. In an interview with WELT, he says: “It’s difficult to get a handle on it.” The hornets not only eat insects, but also attack fruit and vineyards, which can cause significant crop losses.
What makes fighting the Asian hornet so difficult is its special way of life. In spring, a queen builds a so-called primary nest near the ground - in nesting boxes, tool sheds or hedges. Such a nest has even been discovered under a manhole cover, says Richter. The workers grow up in this primary nest.
Now in late summer, the queen and her court set off to build a second, larger nest, the so-called secondary nest, high up in a treetop. Several hundred princesses grow up there. They are mated by drones during their nuptial flight, which turns them into new queens, which then look for winter quarters under the bark of a tree.
Not everyone survives until spring, but apparently enough survives to establish new colonies and continue the rapid advance.
The two nests are not too far apart. And therein lies the approach to effective combat. “If you have discovered a primary nest near the ground, you can specifically search for the secondary nest in the surrounding area,” says Richter. However, they are often difficult to see as long as the trees still have leaves.
With the destruction of the secondary nest, the next generation of hornets is destroyed. The Stuttgart Ministry of Agriculture has therefore offered 200 euros for finding and removing a nest including a queen and princesses. Martin Klatt, species protection officer at the Nature Conservation Association in Baden-Württemberg, clearly believes this sum is too low: “It’s not enough either way.”
The secondary nests at high altitudes can often only be reached with the help of a generally expensive aerial platform, says Klatt. In addition, there are, among other things, the costs for “stab-proof equipment”. Ordinary beekeeper suits do not offer sufficient protection against the aggressive animals.
Carolin Rein, who is responsible for combating hornets at the Baden-Württemberg State Institute for Bee Science, points out the possibility of accessing the nests without a hoist. So-called telescopic lances would be used, through which, for example, hot steam could be directed into the nests.
According to Rein, more than 1,450 founding nests have been removed so far this year, around 500 of which received financial support from the state of 60 euros per nest. In addition, 45 secondary nests have been removed so far, and another 120 have been reported and are awaiting removal.
Funding and public relations work are intended to help slow the spread of the animals and keep their density low, as Rein explains. The fact that more nests were reported than in previous years could already be a sign that the strategy is successful and that attention to the problem has increased.
Climate change may also help in the fight against the Asian hornet in the future. Although the hornets like warmth, they also need water. Hot and dry like this summer, Rein said, is bad for this species.
