Asian hornets: a silent threat we need to understand better

In recent years, Belgium – like many European countries – has been facing the arrival and rapid spread of the Asian hornet (Vespa velutina). Native to South-East Asia, this insect was accidentally introduced to Europe in the early 2000s. It has spread rapidly, largely due to its incredible ability to adapt. Today, it is well established in all regions of Belgium.

What is the Asian hornet?

The Asian hornet is a large black insect, with yellow tips on its legs and an orange band on its abdomen. It should not be confused with the European hornet, which is bulkier and more orange in colour. It is no more aggressive towards humans than an ordinary wasp, unless one gets too close to its nest. However, the proliferation of nests and their low height increase the risk of accidents, particularly for gardeners.

Why is its presence a problem?

The Asian hornet causes:

• A threat to bees: The Asian hornet is a formidable predator of both domestic and wild bees. It can decimate a hive in a matter of days, posing a serious threat to pollination and local honey production. A single colony of hornets can consume thousands of bees in a single season.
• An imbalance for ecosystems: By preying on numerous insect species (159 species according to recent data), the Asian hornet disrupts local food chains. Its rapid proliferation leaves little room for predators or natural competitors. An average Asian hornet nest consumes 11.3 kg of insects per year, whilst a large nest can consume 22.6 kg! This leads to fewer adult (reproductive) insects, which threatens local biodiversity, including in the Brussels region.
• A risk to humans: Although the Asian hornet is not particularly aggressive, it can sting in swarms when its nest is approached. These stings can be very painful and dangerous for people with allergies, potentially leading to emergency hospitalisation.

What can be done?

The fight against the Asian hornet must be collective, coordinated and environmentally friendly. The City of Brussels has launched initiatives to limit the presence and spread of the Asian hornet within its territory.

In early spring, the queens of Asian hornets emerge from hibernation to establish new colonies. This is the time when it is possible to trap these queens before they build a primary nest. So-called ‘selective’ traps can be used, often in the form of bottles or baited devices.

Now is the time for trapping, and anyone with a garden can get involved. You can find all the information on the website https://www.brussels.be/spring-trapping-asian-hornet

It is also useful to report nests: You can join one of the “Vespa Hunters” groups on Facebook, organised by local council area. For BXL 1000, the group is Vespa Hunter 1000: https://www.facebook.com/groups/1952854801737819?locale=fr_FR