Asian hornets: why autumn is the deadliest season for Europe's honey bees

Across Europe, searches for "Asian hornet" spike every autumn, and 2026 is no exception. The insect, scientifically named Vespa velutina, is smaller than the native European hornet but hunts honey bees with unusual efficiency, and French regional outlets reported in early October 2026 that colonies were entering their most aggressive and most destructive phase of the year.

Why October is the critical month

Asian hornet colonies follow an annual cycle: a single fertilised queen founds a nest in spring, and the colony grows through summer before reaching its maximum size in early autumn. According to Wikipedia's summary of the species' biology, nests built high in trees can house several thousand individuals by the time colonies peak, egg-shaped structures of at least 50 centimetres long.

That peak coincides with the highest food demand of the year, as the colony needs to raise new queens that will leave the nest in late autumn to hibernate and found next year's colonies. This is why French beekeeping regions such as the Alpes-Maritimes reported unprecedented pressure on apiaries in late summer 2026, according to a report by France 3 Provence-Alpes-Côte d'Azur.

How the hornets kill bees

Asian hornets do not attack hives directly in large numbers. Instead, individual hornets establish a hunting position near a hive entrance and intercept foraging bees as they return home, a behaviour entomologists call "hawking." Wikipedia's entry notes that as soon as one hornet catches a bee, it flies off to process the prey and another hornet typically takes its place, maintaining constant pressure on the colony.

The species' impact is worsened by a biological mismatch: the Western honey bee (Apis mellifera), commonly kept in Europe, has not evolved an effective defence against this predator. By contrast, the Eastern honey bee (Apis cerana), native to the hornet's original range in Asia, can form a tight ball around an attacking hornet and raise the temperature inside the ball to a level that kills the hornet while the bees survive — a defence Western bees rarely manage as effectively, per the same Wikipedia summary of the species.

The practical effect at hive level is that bees become reluctant to leave the hive to forage, a phenomenon beekeepers describe as colonies losing "dynamism" under hornet pressure near the entrance.

From a single nest in France to a continental invasion

The Asian hornet is native to parts of Southeast Asia, including China, Vietnam, Thailand and neighbouring countries. It reached Europe accidentally, with the first colony recorded in 2004 in France, believed to have arrived in imported pottery from China, according to Wikipedia's account of the invasion history; by 2009, thousands of nests had been found around Bordeaux, per the same source.

From that single introduction, the species spread rapidly: Spain in 2010, Portugal in 2011, Belgium in 2011, Italy in 2012, Germany in 2014, the United Kingdom in 2016, the Netherlands in 2017, Luxembourg in 2020, Hungary in 2023 and Ireland in 2025, per the same source. Isolated detections have also been reported outside Europe, including near Savannah in the U.S. state of Georgia in 2023 and in Auckland, New Zealand, in 2025.

The United Kingdom's 2026 season in numbers

In Britain, where the hornet is a newer arrival, the government's National Bee Unit — part of the Animal and Plant Health Agency (APHA) — tracks sightings and nest discoveries. As of 3 September 2026, the unit had recorded 167 credible sightings and 53 confirmed nests nationwide for the year, according to figures reported by pest-control industry site JG Pest Control, which cited the official National Bee Unit rolling update.

Most UK nests remain concentrated in Kent, but confirmed finds in 2026 extended to Hampshire, Surrey, East Sussex, Norfolk, Dorset, Derbyshire and, for the first time that far north, Greater Manchester, where a secondary nest was found in Chadderton on 19 August 2026. The earliest nest of the season, an embryo nest, was recorded in Chesterfield, Derbyshire, on 26 April.

Responding on the ground

In long-established areas such as southern France, efforts have shifted from full eradication toward limiting damage to bee colonies. Destroying nests before autumn, when queen production peaks, remains the primary official method recommended to beekeeping associations.

Some beekeepers have also adopted physical barriers. In the Alpes-Maritimes, France 3 reported on the use of an "electric harp" — a frame of vertical wires carrying a low-voltage current that is installed in front of hive entrances. When a hornet touches two wires simultaneously while attacking a bee, it receives a shock described in the report as a "violent discharge," strong enough to kill the hornet but, according to the report, harmless to the honey bees and to humans.

• Nest destruction, particularly before the autumn queen-production peak, is the main official control method.
• Monitoring traps are used to track hornet activity near apiaries, though broad trapping can also catch native, non-target insects.
• Physical barriers such as electric-wire "harps" placed at hive entrances are being tested by individual beekeepers in affected regions.
• Public reporting of sightings and nests to national schemes (the UK's National Bee Unit, equivalent regional networks elsewhere) helps authorities track the species' spread.

Wider ecological concern

Beyond honey bee colonies kept for honey production and crop pollination, biologists caution that Vespa velutina can prey on other pollinating insects, meaning its ecological footprint extends past managed apiaries into broader pollinator communities, though the honey bee impact remains the most extensively documented effect of the species' spread across Europe.