The European hornet (Vespa crabro) is a hymenopteran present throughout Europe. Often confused with the Asian hornet (Vespa velutina), it is important to know its characteristics for proper management. This guide provides information on the risks and prevention methods for a peaceful coexistence with this native species.
Identification and Characteristics of the European Hornet
The European hornet measures between 20 and 35 mm long. The queen, larger, can reach 35 mm. It is characterized by a dark brown body striped with orange-yellow, with a reddish head. Unlike the Asian hornet, smaller and darker, the European hornet has wider yellow bands and a more robust head. The wingspan is approximately 4 to 7 cm.
Geographic Distribution and Population Density
The European hornet is widely distributed in Europe, except in the northernmost areas. Its population density varies by region and year, influencing the size of local populations. Higher concentrations are noted in rural areas rich in deciduous or mixed forests. Oak forests, for example, are a preferred habitat. In France, it is estimated that about 70% of nests are located near forests.
Factors such as the availability of food resources, temperature, and natural predation influence the size of colonies. For example, a particularly hot year can lead to a faster development of colonies, leading to an increase in the number of nests.
Studies have shown a fluctuation of 10 to 20% in the European hornet population between years, depending on climatic conditions and prey availability. This underlines the importance of monitoring populations for sustainable management of the species.
Life Cycle and Social Organization of the European Hornet
The life cycle begins in spring, with the founding queen. She builds a nest, often in a tree cavity or a human structure (attics, lofts), and lays her first eggs. The colony grows rapidly, from a few individuals in the spring to several hundred by the end of summer. A colony can house from 100 to 700 individuals at its peak. The social structure is well organized, around a queen, sterile workers, and males.
In autumn, only the fertilized queens survive the winter. The other individuals die, and the nest is usually abandoned. On average, a queen produces about 300 workers per year, with a productivity that can vary depending on resources and temperature.
Nest construction is done from chewed plant fibers mixed with saliva, creating a material similar to papier-mâché.
Dangers of European Hornet Stings and Risk Groups
The sting of a European hornet is painful due to the injected venom. Symptoms include intense pain, swelling, and redness at the sting site. In allergic individuals, a more serious reaction may occur, ranging from hives to anaphylactic shock. In extreme cases, an allergic reaction may require rapid medical intervention.
Risk groups: Children, the elderly, and people allergic to hymenopteran stings are at risk. Allergic individuals are advised to consult a doctor and carry emergency treatment in case of a sting. European hornet venom contains more allergenic components than that of some wasps or bees.
According to the Pasteur Institute, about 15% of the French population is allergic to hymenopteran venom. It is important to know your health condition and take the necessary precautions.
- Consult a doctor if you have a known allergy
- Carry emergency treatment (adrenaline) in case of allergy
- Monitor reactions after a sting, especially in children and the elderly
Environmental Impact of the European Hornet on Biodiversity
The European hornet, an insectivorous predator, plays a role in the balance of ecosystems. It feeds mainly on other insects, including flies, wasps and bees. Although this predation can affect some insect populations, its overall impact on biodiversity remains limited. It is important to consider the role of the European hornet in the natural regulation of insect populations.
Studies have shown that bee predation by European hornets is limited. Indeed, bees adopt strategies to avoid hornets, such as rapid returns to the hive and collective defense of the nest. In addition, the amount of prey captured by a European hornet over a period of time is limited, typically 2 to 5 insects per day.
There is competition with other predatory insects, such as spiders and insectivorous birds. This contributes to an ecological complexity that cannot be reduced to a simple positive or negative impact.
Myths and Realities: The Perception of European Hornet Aggressiveness
The European hornet is not inherently aggressive. It only attacks if it feels threatened, especially near its nest. It is important to keep your distance and avoid disturbing it. Sudden movements and vibrations can be perceived as a threat. The European hornet is primarily a hunter focused on its prey.
Stings occur mainly during careless handling of the nest or direct contact with the insect. Contrary to popular belief, the European hornet is not attracted to humans, but rather to food sources such as insects and ripe fruit. Respecting its living space is usually enough to avoid conflict.
Prevention Strategies and Nest Management
Prevention begins with reducing attracting factors. Waste management, the elimination of fallen ripe fruit, and sealing cracks in walls and roofs limit the possibilities of nest installation. It is advisable to regularly check attics and areas likely to house a nest.
- Maintain impeccable cleanliness around the house
- Repair cracks and openings in walls and roofs
- Cover bins tightly
- Pick up fallen fruit
Regular monitoring of at-risk areas allows for early detection. Professional intervention is essential for the safe management of nests.
Identification and Monitoring of European Hornet Nests
Nests are usually built in cavities (tree trunks, cracks, attics). They look like large balls of grayish paper. It is crucial not to approach or attempt to destroy them yourself. Accurate identification requires the expertise of a professional. A nest can house up to 700 individuals. Observation from a distance is the best way to ensure safety.
Visual identification can be difficult, and confirmation by an expert is often needed to differentiate the nest of a European hornet from that of other species. Photos can be helpful in facilitating identification, but an on-site examination by a professional is preferable to avoid confusion.
Professional Intervention and Management of European Hornet Nests
Professional intervention is necessary if the nest is close to a dwelling, if the number of hornets is significant, or if allergic individuals live nearby. Nest destruction should be entrusted to properly equipped and trained professionals. Their interventions reduce the risk of stings and ensure safe elimination. The use of specific insecticides is often necessary.
According to local regulations, firefighters or companies specializing in pest management can intervene. The cost of the intervention varies depending on the location, size of the nest and accessibility. It is recommended to obtain several quotes before any intervention.
Alternative Solutions to Destruction: Translocation and Non-Lethal Methods
In some cases, nest translocation is possible. This method involves moving the nest to a new, suitable location. However, this technique is complex and requires specific expertise. It is not always feasible and depends on factors such as nest size, season and site accessibility. Only qualified professionals can carry out a translocation.
Research continues to develop non-lethal methods for managing European hornets. Techniques such as targeted destruction of the queen or disruption of the colony are being studied. However, their effectiveness remains to be demonstrated on a large scale. These methods remain experimental and are not widely available.
Coexistence with European hornets is possible. A responsible approach, combining prevention, monitoring and professional intervention, makes it possible to reconcile the safety of populations and respect for the environment.