An invasive hornet species that preys on honeybees has been confirmed in Poland for the first time, with scientists discovering a large, active nest in a valley near Kraków. The finding raises concerns that the Asian yellow-legged hornet, which has spread across Western Europe and damaged beekeeping operations, could begin establishing itself in Poland.
The nest was discovered on 14 October in the Kluczwoda Valley near Wielka Wieś, approximately 15 kilometres northwest of Kraków, following an investigation involving scientists, beekeepers and environmental protection officials.
The insect, scientifically known as Vespa velutina, is commonly called the Asian hornet or yellow-legged hornet. It is an invasive species originally from Southeast Asia that has progressively spread across Europe.
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According to a detailed field investigation published by specialist beekeeping publication Pasieka24, the nest was located in a poplar tree approximately 10–15 metres above ground.
Researchers estimated its diameter at 60–80 centimetres and observed substantial hornet activity, indicating an established colony.
The discovery represents the first documented nest of the species in Poland, although the insects’ geographical origin and the extent of their presence remain unknown.
Only one nest has so far been confirmed, and scientists have not established that the species is permanently established in Poland.
From an online photograph to Poland’s first nest
The investigation began with photographs rather than an official wildlife survey.
On 26 September, a user of the wildlife identification platform iNaturalist uploaded a photograph of an unidentified insect.
Other users suggested that the insect resembled Vespa velutina, an identification subsequently supported by specialists.
The observation initially attracted limited attention.
Further evidence appeared on 11 October, when beekeeper Grzegorz Małek posted photographs from his apiary in Wielka Wieś on a Polish beekeeping forum.
The following day, the photographs were shared more widely, prompting scientists and experienced beekeepers to investigate.
Among those involved were Dr Łukasz Nicewicz of the University of Silesia, Dr Paweł Migdał of Wrocław University of Environmental and Life Sciences, researchers associated with the Jagiellonian University and specialist beekeepers familiar with the species.
Entomologist Dr Waldemar Żyła independently examined the photographs and confirmed the insects’ identification as Vespa velutina.
On 14 October, two teams began field investigations near Kraków.
At an apiary in Wielka Wieś, researchers observed numerous hornets, captured specimens for examination and followed the direction of their flights to identify where they might be nesting.
The search led to the Kluczwoda Valley, where researcher Wojciech Solarz located the nest high in a poplar tree.
The team found the colony remained active, with substantial numbers of hornets responding to disturbances near the tree.
Representatives of the Regional Directorate for Environmental Protection in Kraków also participated in the field investigation.
Why the Asian hornet is a threat to honeybees
The species is of particular concern to beekeepers because it hunts other insects, especially honeybees.
Unlike predators that only occasionally capture bees, Asian yellow-legged hornets can repeatedly hunt around beehive entrances, intercepting worker bees as they return from collecting nectar and pollen.
Dr Nicewicz explained in comments reported by the Polish Press Agency that the presence of predatory hornets can substantially reduce bee activity around hives.
When foraging bees are repeatedly caught, colonies can lose large numbers of workers. The remaining bees may also become reluctant to leave their hives.
That can reduce the amount of food collected and weaken the colony, potentially threatening its survival.
The hornet also hunts other insects, meaning its ecological impact is not restricted to managed honeybee colonies.
Poland’s General Directorate for Environmental Protection identifies the hornet as an invasive alien species capable of harming beekeeping and competing with native insects.
The principal concern is therefore agricultural and ecological, rather than the hornet presenting an exceptional new danger to humans.
Like native hornets, it can sting when disturbed or defending its nest, but its presence should not be confused with an extraordinary threat to the general public.
Individual hornets also detected in Kraków
Researchers have identified a second location where the insects have been observed.
At an apiary operated on the campus of AGH University of Kraków, a hornet was captured on 1 October and subsequently provided to investigators.
The university apiary is approximately 11 kilometres from the Wielka Wieś site.
Scientists investigated the campus on 14 October but did not locate another nest.
The distance between the two locations raises the possibility of additional colonies, but does not prove that one exists near the university.
According to the Pasieka24 field account, the researchers left monitoring equipment at the site to help establish whether hornets continue appearing.
Captured specimens are also expected to undergo genetic analysis.
Dr Nicewicz told PAP that researchers want to determine whether the insects reached southern Poland through the gradual expansion of populations elsewhere in Europe or were accidentally transported from another region.
The hornet has previously been recorded in countries including Germany and the Czech Republic.
The scientists have not established which route brought the insects to Poland.
Specialists from France expected to remove the nest
The immediate priority is to deal with the confirmed nest before the colony can produce additional queens capable of surviving winter.
Autumn is particularly important in the hornet’s reproductive cycle because fertilised young queens may disperse and find sheltered places to overwinter.
Those that survive can potentially establish new colonies the following spring.
The nest discovered near Wielka Wieś was already well developed, raising concern that some future queens may have begun dispersing.
However, researchers cannot yet determine how many have left or whether any will successfully establish new colonies.
The field team did not remove the nest on 14 October because its height and location required specialist equipment and appropriate safety procedures.
According to PAP’s reporting published on 16 October, a specialist team from France is expected to travel to Poland during the following week to carry out the removal.
French specialists have extensive experience dealing with the species following its spread through their country.
As of 16 October, removal had not been independently confirmed.
The operation could reduce the risk of further dispersal from the identified colony, although it cannot establish whether additional nests or overwintering queens are already present.
An invasive species spreading across Europe
The Asian yellow-legged hornet was first documented in France in the early 2000s, with 2004 commonly cited as the year of its initial detection.
It has since spread to numerous European countries, becoming an established problem for beekeepers in parts of Western Europe.
Its expansion has been assisted by its ability to establish colonies in different habitats, including woodlands, agricultural areas and urban environments.
Fertilised queens can also be accidentally transported over long distances in goods, wood products and other materials.
The species is distinct from the much larger Asian giant hornet, sometimes sensationally referred to as the murder hornet.
The yellow-legged hornet is generally smaller than Poland’s native European hornet and can be recognised by its predominantly dark body, orange-yellow markings towards the end of its abdomen and distinctly yellow lower legs.
However, identification can be difficult without a clear photograph or specialist examination, particularly when insects are observed briefly.
Its appearance in Poland had been anticipated by scientists tracking the hornet’s spread through neighbouring European countries.
The finding near Kraków is nevertheless significant because it documents an active colony rather than simply an isolated insect arriving from elsewhere.
What happens next?
The discovery presents Polish environmental authorities and researchers with two immediate challenges: removing the known nest and determining whether other colonies are already present.
Further monitoring is expected around Kraków and neighbouring areas, while genetic testing may provide clues about how the insects arrived.
Under Poland’s invasive-species reporting system, suspected new occurrences can be reported to local municipal authorities, which coordinate the information with the relevant environmental protection bodies.
The Regional Directorate for Environmental Protection in Kraków provides guidance on reporting invasive species.
Residents who encounter a suspected Asian yellow-legged hornet should record the location and, where it can be done safely, obtain a photograph for identification.
They should not approach suspected nests or attempt to destroy them themselves.
For now, the discovery marks a significant new stage in the species’ spread across Europe, but the scale of its presence in Poland remains uncertain.
Whether the hornet becomes an established problem for Polish beekeepers will depend partly on how widely it has already dispersed and how effectively further colonies can be detected and managed.
