Asian Hornet Surge in Belgium Prompts Urgent Warning

A professional pest controller in Flemish Brabant has raised the alarm over a dramatic increase in Asian hornet nests, warning residents that the invasive species is spreading at an alarming rate and urging them to look down rather than up when searching for nests. Kurt Bellon, a 23-year veteran pest controller at Antimal in Malderen, destroyed six nests in a single day this week, with some reaching the size of a volleyball.

“I did six in one day yesterday,” Bellon told Het Laatste Nieuws. “I think it will be at least as bad as last year, maybe worse.”

The Growing Threat

The Asian hornet (Vespa velutina), also known as the yellow-legged hornet, is an invasive species that first arrived in Europe via international trade, detected in southern France in 2004. It reached Belgium in 2016 and has been spreading exponentially ever since. According to Nicolas Pardon, a hornet specialist at the Flemish Agency for Nature and Forest (ANB), the population grows by a factor of three to four every season.

Citizen science data confirms this trajectory. In 2024, volunteers recorded 1,628 traps and 3,984 caught queens. By 2025, those numbers had surged to 4,067 traps and 15,880 caught queens — a fourfold increase, as reported by VRT NWS.

Bellon’s experience mirrors this trend. In 2022 he destroyed six nests; in 2023 that number rose to 21, according to earlier VRT reporting. Now, in just three days this July, he has been crisscrossing the streets of Malderen and Steenhuffel — both in the Londerzeel municipality — destroying nest after nest.

Where to Look: Down, Not Up

A key message from Bellon is that residents should change how they search for nests. While many instinctively look up into trees, the greatest danger during the first part of the season lies close to the ground.

“Those nests can really be anywhere,” Bellon warned. “In a paper container that hasn’t been moved for weeks, under a cover sheet, in an overturned wheelbarrow, in a compost bin, a chicken coop, a dovecote, or a garden shed.”

Asian hornets build two types of nests. Primary nests are constructed in spring by the queen in sheltered, low-lying locations. Later in the season, the colony moves to a larger secondary nest, often high in trees at 12 to 30 meters, where they become nearly invisible through the foliage. By the time leaves fall in late October and these nests become visible, new queens may have already departed to establish next year’s colonies.

Ecological and Public Safety Concerns

The Asian hornet poses a serious threat to honeybees and other pollinators. They station themselves outside beehives, capturing foraging bees mid-flight, and can decimate local bee populations. This threatens honey production, crop pollination, and broader biodiversity.

While experts note that Asian hornets are generally not aggressive toward humans unless their nest is disturbed, Bellon’s personal experience illustrates the real danger. “I’ve been stung several times myself,” he said. “I was once attacked and stung in my eyebrow and eyelid. They also sprayed venom toward my eye.” Having been stung over 215 times in his career, Bellon stresses that people with allergies face particular risk of anaphylactic shock.

Policy Challenges and the Fight Ahead

A significant obstacle to control efforts is the lack of coordinated action between Belgium’s regions. Bellon noted that Wallonia does not actively destroy Asian hornet nests. Since the hornets enter Belgium from France through Wallonia, this creates a continuous source of re-infestation for Flanders.

Both regions have shifted strategy from eradication to damage control, as Agroberichten Buitenland reported in March 2026. Wallonia allocated €1 million for a new action plan in 2026, while Flanders is investing in innovative solutions including AI-powered selective traps and digital nest-detection technology.

The Instituut voor Natuur- en Bosonderzoek (INBO) emphasizes that eradication is no longer realistic. The focus is now on limiting impact on protected nature, reducing nuisance at beehives, and intervening where public safety is at risk.

What Residents Should Do

Bellon urges residents not to approach or attempt to seal off suspected nest entrances. “Don’t stuff a towel or rag in there and especially don’t seal the hole,” he warned. “The animals might then look for another way out, sometimes into the house.” Instead, residents should keep their distance, take a photo if safe to do so, and contact a certified professional destroyer.

With the Asian hornet population showing no signs of slowing its exponential growth, the message from those on the front lines is clear: vigilance, early reporting, and professional destruction are the best tools available to slow the spread of this formidable invasive species.