13,000: the number of individuals a single Asian hornet nest can produce in one season

Key Takeaways

The key figure: an Asian hornet nest can produce up to 13,000 individuals in a single season (April to December), according to the 2015 study by the National Museum of Natural History.

The mechanism: it all starts with a single queen emerging from hibernation in March. A few months later, the colony numbers up to 2,000 simultaneous adult individuals, and has produced a total of up to 13,000 hornets over the season.

The real impact of a single nest:

• More than 11 kg of insects consumed per season (bees, flies, wasps, pollinators)
• 500 to 1,000 future queens released in autumn, ready to found their own colonies the following year
• An impact radius of 700 m to 1 km around the nest

The strategic lesson: 1 queen captured in spring = 1 nest avoided = 13,000 fewer hornets = 500 to 1,000 future queens that will never see the light of day. This is the whole point of spring trapping, provided it is selective.

Where exactly does this figure come from?

Before diving into the consequences, let's establish the rigor of the figure.

A team composed of researchers from the Institute of Systematics, Evolution, Biodiversity (Museum/CNRS/EPHE/UPMC) and the Institute for Research on Insect Biology in Tours (CNRS/François Rabelais University) conducted the first in-depth study of the evolution of Vespa velutina colonies. Until then, this hornet was well known in Asia, but its biology in an invasive environment had never been precisely described.

Method

• 77 nests collected between 2007 and 2010 through a network of beekeepers, municipal agents, and pest controllers
• Dissection of each nest according to a standardized protocol
• Counting of eggs, larvae, pupae, and adults
• Weighing of nearly 2,800 females to distinguish workers and future queens

Published result: a Vespa velutina colony can produce up to 13,000 individuals between April and December, with a maximum of 2,000 adults in October. Nest size correlates with the number of individuals produced. The study was published in the Journal of Applied Entomology, Rome et al., 2015.

There you have it. This figure is neither an average nor an approximation: it's the maximum observed for the largest nests. But this maximum is not exceptional; it is regularly reached in the most colonized regions.

Understanding the Exponential Mechanism

How does one go from a solitary queen in March to 13,000 individuals in October? The answer lies in one word: exponential.

Here is the month-by-month breakdown.

March-April: the queen emerges

A single female, fertilized the previous autumn, emerges from hibernation. She seeks sugar (to regain strength), then a sheltered location to establish her primary nest — often in a shed, under an awning, or in a roller shutter box. The nest is then the size of an orange.

At this stage: 1 active individual (the queen). To understand the entire seasonal cycle of a colony in detail, consult our dedicated page on the seasonal cycle of an Asian hornet colony.

May-June: the first workers

The queen lays her first eggs. She herself feeds the larvae, which become the first workers. The first workers emerge in May and measure only between 14 and 16 mm. From then on, the queen stops foraging: she dedicates herself exclusively to laying eggs. The workers take over to feed the larvae and enlarge the nest.

At this stage: 20 to 50 individuals.

June-July: the big move

The colony needs more space. It abandons the primary nest and builds a secondary nest, usually very high in a tree (15 to 20 m). This spherical nest becomes visible in autumn after the leaves fall. Growth accelerates.

At this stage: several hundred individuals.

August-September: demographic explosion

This is the phase of exponential growth. Each worker feeds several larvae, which in turn become workers, who in turn feed... The colony produces continuously, day and night.

At this stage: 1,500 to 6,000 active individuals simultaneously.

October: peak and reproduction

The maximum number of adults is reached in October: about 2,000 simultaneous individuals. But this figure hides the reality: over the entire season, the colony has produced much more, because workers only live 30 to 40 days. They have succeeded each other in waves.

It is also at this time that the colony produces its males and future queens. Nearly 2,000 workers raise at least 500 future queens, but probably more than a thousand, and as many males.

November-December: collapse

The first frosts kill the workers and males. The nest dies. But the future queens, fertilized in the meantime, have already taken shelter to overwinter.

Total balance sheet for the season: up to 13,000 individuals produced, including 500 to 1,000+ future queens, each of whom will start their own colony the following year.

What This Number Concretely Means

13,000 individuals. To truly understand what that represents, let's translate it into real-world terms.

In prey consumed

A single nest consumes over 11 kilograms of insects each year to feed its larvae. This represents, according to estimates, several tens of thousands of insects: domestic bees, solitary bees, butterflies, hoverflies, native wasps, flies. This figure comes from the National Assembly parliamentary report citing MNHN data.

For a nearby hive, it's catastrophic. In Asia, Vespa velutina can destroy up to 30% of an Asian honeybee colony. In Europe, where domestic bees have no defense against this predator, losses can be much higher in heavily attacked apiaries.

In territorial spread

A colony that produces 500 to 1,000 queens in autumn potentially means 500 to 1,000 new nests the following year. In reality, many queens do not survive the winter, and many others fail to establish their colony. But even with a success rate of 5%, one mature nest generates 25 to 50 new nests the following year.

This is how the invasion front progresses by an average of 78 km per year since the Asian hornet's arrival in France in 2004.

In local impact

Imagine your neighborhood. A nest 500 m from your home means:

• 13,000 hornets circulating within a 700 m to 1 km radius around the nest
• Several hundred possible daily visits to your garden
• Risks of hovering flight in front of neighboring hives
• Intensive hunting of pollinators on the neighborhood's flower beds

And all this, from a single queen that could have been intercepted in the spring.

The Crucial Lesson: Spring's Leverage

This is where this figure becomes politically and strategically decisive.

If a single nest produces 13,000 individuals, and if a single queen can give birth to a nest... then every queen captured in spring is a high-impact event.

Simple math:

• 1 queen captured in March-April
• = 1 nest avoided in summer
• = up to 13,000 fewer Asian hornets
• = approximately 11 kg of beneficial insects saved
• = 500 to 1,000 future queens that will never see the light of day

This is why spring trapping, even if it is sometimes criticized in certain configurations, remains scientifically justified when it is targeted and selective. An intercepted queen has an enormous leverage effect. To learn more, read our dedicated page on spring trapping of Asian hornets.

Important clarification: not all traps are created equal. A non-selective trap (homemade cut-up bottles, for example) also captures bees, butterflies, and other pollinators. Studies by MNHN and INRAE show that over 99% of insects captured in these artisanal traps are not the intended target. This is counterproductive.

A selective trap — designed to allow beneficial insects to escape through calibrated openings — radically changes the equation. It is the only format today scientifically defensible for spring trapping.

And after spring?

Spring trapping is only one link in the strategy. It must be complemented by:

Reporting visible nests

If you see an active nest (or now, in autumn, after the leaves have fallen), report it on dedicated platforms  or to your local town hall. This contributes to national mapping and enables targeted professional destruction.

Protection of apiaries

For beekeepers, electric harps placed in front of hives during the predation season (July to October) significantly reduce attacks, without capturing non-target species.

Community action

Communes that structure an anti-hornet plan — distributing traps to residents, coordinated reporting, regular communication — see their reported and destroyed nests decrease sustainably over 2 to 3 seasons.

One Queen, One Protected Neighborhood

13,000.

When you see an Asian hornet in your garden in April, it's not just an annoying insect. It's potentially the start of a colony of 13,000 individuals that will consume 11 kg of local pollinators and release 500 to 1,000 queens in the autumn.

It's this exponential mechanism that makes the Asian hornet so formidable. And it's this same mechanism that makes every spring action disproportionately effective.

One queen. One well-placed trap. One neighborhood protected for the entire season.

That's the beauty—and the difficulty—of fighting invasive species: small actions, at the right time, have enormous effects.

Buzz you soon, Buzette.

Want to intercept a queen before she founds a nest of 13,000 individuals? Discover Hornet EcoTrap, the selective trap made in France that acts at the most effective time of the biological cycle, without harming bees or other pollinators.

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