the new enemy of the honey bee – or just a misunderstanding?

Rolf Witt is upset – and that has to do with a small insect: the Asian hornet. However, his displeasure is not directed at the animal itself, but at the reactions it triggers in many people. “In my opinion, exaggerated, irrelevant claims are made about the hornet and there is too much panic,” says the biologist. He alludes to warnings from beekeepers’ associations that the hornet is the honey bee’s new enemy, a dangerous invasive species that is destroying their bee colonies. “The Asian hornet is not the species that bothers our honey bees,” Witt clarifies, “it’s more the lack of flowers, the environmental toxins and so on.”
But how did this misunderstanding come about?
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Why climate change is helping the hornet
The Vespa velutina, the Latin name for the Asian hornet, actually comes from Southeast Asia. It finds its way to Europe unnoticed, presumably with the help of imported goods from Asia in shipping containers. It was first discovered in 2004 near the French city of Bordeaux. Within a short time, it manages to spread across large parts of France and eventually reaches other countries such as Belgium, Spain, the Netherlands and Italy.
In Germany, the hornet species was first detected in 2014 in the Baden-Württemberg town of Waghäusel, about 22 kilometers as the crow flies from Heidelberg. From there it spreads to neighboring federal states such as Hesse and Bavaria; meanwhile even an island population lives in Hamburg. There are no exact figures on how large the stocks are in this country, partly because the hornet builds its nests high up in the trees, hidden in the dense foliage, where they are difficult to find.
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Only when the trees lose their leaves do the nests of the Asian hornets appear.
© Source: DLR-WO/FBI Mayen/dpa
Climate change plays into the hands of the Asian hornet as it spreads. Because it is getting warmer and the winters are getting milder even in the Global North, the hornet is finding more habitats. Studies like that of Museu National d’Histoire Naturelle in Paris predict that the insects could even advance to Scandinavian countries in the near future. Witt is convinced: “Even without climate change, the species would occur at least in parts of southern Germany.”
Asian hornet is outlawed in Europe
The fact that the Asian hornet has spread so quickly and extensively in Europe has meant that it has been on the Union list since 2016. There, the European Union names all animal and plant species that can affect habitats, species or ecosystems with their spread and thus damage biological diversity.
And with this inclusion on the Union list, Otto Boecking believes that the “dilemma”, as he calls it, has taken its course. Because if a species is classified as invasive, states are obliged to combat it at an early stage of distribution. If comprehensive control is no longer possible, the ordinance provides for management measures.
“If you are going to fight the Asian hornet, then please use common sense and understanding,” demands the scientist from the Laves Institute for Apiculture in Celle. This means, for example, not setting traps. Because the bycatch of other, sometimes rare, species is so large that it causes much greater damage, explains Boecking. Data from France would have shown anyway that the elimination measures have no impact on the spread of the hornet.
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Sometimes annoying, but useful: why wasps are so important
When they see a wasp, many people panic or get annoyed. Insects have the reputation of being useless and aggressive parasites. They are an important part of the ecosystem – and suffer from their bad image.
In France, the Asian hornet is being massively combated. According to Boecking, the country invests several million euros every year to get rid of the insects. If the hornet species spreads as forecast, similar expenses could also come to Germany. “The question is whether you take measures and use money that is then not available for other nature conservation measures, and in the end it has no effect at all,” the bee expert points out.
Hornet is an omnivore
Hornet expert Witt considers the general fight against the Asian hornet to be an approach “in which basic ecological understanding is missing”. For example, it is “completely pointless” to laboriously remove orphaned nests from the trees in the winter months. Especially since the hornet does not pose an increased risk to humans. “It’s not harmless,” says Witt, “but neither is a honey bee.” Anyone who doesn’t react allergically to insect bites feels the sting of the Asian hornet just as painful as that of the European hornet.
What is the difference between the Asian and the European hornet?
Visually, both hornet species are difficult to distinguish from each other, even if there are color differences. The body of the Asian hornet is predominantly black and its legs are yellow, giving it the name “yellow-legged hornet”. Their abdomen and head shield are orange to yellowish. The European hornet, which is slightly larger, has a reddish-brown base coloration of the head, chest, and legs. Their abdomen is black and yellow. There are also differences in their nests: The Asian hornet builds larger nests (up to 100 centimeters) with more combs (four to ten), writes the Bavarian LWG Institute for Beekeeping and Apiculture. In addition, the hornet species prefers high trees for its nest building and flies sideways into its nest. The European hornet, on the other hand, prefers to build its nests (up to 60 centimeters in size with five to eight combs) in sheltered caves and with an entrance hole on the underside. The biggest difference between the two species, however, is their protected status: while the Asian hornet is widespread in Europe, the European hornet is now considered an endangered species, according to Nabu.
And according to the experts, the hornet will not kill honey bees either. “Yes, the Asian hornet can pose a certain threat,” says Boecking, “but we also know that strong colonies can deal with it.” Weakened colonies, on the other hand, have a harder time defending themselves against the hornet. “The hornet is opportunistic — that is, it takes what’s available most.” As a result, the Asian hornet eats more bees in urban areas where there are more beehives, and less in areas where there are few honey bees. “You can’t say it feeds exclusively on honey bees,” Boecking clarifies. “That’s downright nonsense.” Flies and mosquitoes, beetles and wasps are also on their menu.
Another reason why the Asian hornet hunts honey bees is that they are easy prey. The honey bees slowly approach their hives like helicopters. This makes it easier for the hornet, which is a talented flyer, to catch them in flight in time. “I always say: She can still do a somersault backwards and snatch a honey bee in the process,” says Witt. He admits that the Asian hornet can cause minor losses, especially in weak bee colonies, but the European hornet also eats honey bees – and they are not classified as an invasive species, but are protected by law.
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Honey bees sit on a brood comb from a beehive: the bees are a favorite food for the Asian hornet.
© Source: Robert Michael/dpa
If the Asian hornet were not classified as an invasive species and control was not mandatory, beekeepers would not actually have to kill the animals to protect their honey bee colonies. Instead, they could use “deterrent measures,” as Witt calls it. There are various options here: For example, perforated sheets could be mounted in front of the entrance to the beehive. The holes in it are so big that the bees can barely fit through, while the hornets are too big for it. Or with twigs and bushes in front of the flying board on the beehive, the hornet’s hunt can be hindered. “Beekeepers are asked to develop appropriate specific methods and take measures,” says Witt.
However, one thing is clear: no matter what measures are taken against the hornet species, it can no longer be completely driven away. “You have to live with the fact that it’s there,” says bee expert Boecking frankly. “She came to stay.”