Trapping Asian hornets in March 2026: Guide and strategy

Contents

• The awakening of the founding queens in March: why the climate emergency demands action

• Comparing solutions: free communal traps vs. selective professional devices

• A successful trapping campaign: strategic recommendations and system limitations

• Conclusion

The first rays of sunshine in March 2026 are the signal. Not just for your crocuses and bees. It's also the moment when the founding queens of the Asian hornet emerge from hibernation, hungry and ready to found a new colony. And each queen not captured at this stage means a potential nest of 6,000 individuals this summer.

Things to remember

• In the face of the March 2026 thaw, this article scientifically deciphers why the first few days of sunshine are crucial for capturing queens.

• We compare municipal systems with professional solutions to guarantee selective and effective trapping without harming local biodiversity.

• Why the climate emergency demands action

• Free communal traps vs. selective professional devices

For the past 1 or 2 years, local authorities have been obliged to structure their control measures. As a result, free traps are being distributed everywhere, and trapping campaigns are being organized at municipal and inter-municipal levels. Is this good news? Yes, but it's not enough to guarantee effective trapping that respects biodiversity. You need to understand the right timing, choose the right device, and above all not trap just anything.

At Pest Patrol, we've been working with individuals and communities on these issues for several years. Here, we'll give you what we really know: the science behind the calendar, the practical differences between the traps available, and the mistakes that can do more harm than good.

The awakening of the founding queens in March: why the climate emergency demands action

Each year, the life cycle of Vespa velutina follows the same pattern. In autumn, colonies produce sexed queens. These mate, leave the nest, then seek shelter to spend the winter: woodpiles, attics, tree bark, sometimes even storage boxes in a garage. The rest of the colony dies. Only the founding queens survive.

And that's where March comes in. As soon as temperatures regularly rise above 12-13°C, these queens emerge from their winter diapause. They have an immediate need for sugar to replenish their energy reserves. They visit the first flowers, the sap, anything that can provide them with carbohydrates quickly. This is their moment of maximum vulnerability: they are alone, with no workers to protect them, and focused on finding food.

The problem is that the calendar is changing. Data from the Muséum national d'Histoire naturelle show that hibernation emergence dates are shifting. Observations of active queens as early as the end of February have been documented in the south-west for several years. Today, with the mild winters we're experiencing, even in the Île-de-France and Brittany regions, awakening may come earlier than previously thought. A study published in Journal of Pest Science (Rome et al., 2021) confirms that the phenology of the Vespa velutina is directly correlated with accumulated positive temperatures at the end of winter.

Why is it so important to capture them at this stage? The figures speak for themselves. A founding queen captured in March means a primary nest that will never see the light of day. A primary nest not destroyed means a secondary nest in summer, sometimes more than 20 meters high in a tree, almost impossible to treat without a cherry picker and professional intervention. The MNHN estimates that a single mature Asian hornet colony can consume up to 11 kg of insects per season, including a significant proportion of honeybees. The cascade effect on local biodiversity and apiaries is easy to understand.

Vespa velutina was already classified as an invasive alien species, but the destruction of nests and the organization of spring trapping were left to the goodwill of local authorities. It's a real lever. It remains to be seen whether the resources deployed are commensurate with the problem, and whether the devices distributed are truly selective. Trapping the founding queens of the Asian hornet is not just a matter of placing a jar of beer at the bottom of the garden. Trap selectivity is a major issue. We'll come back to this in a moment.

Comparing solutions: free communal traps vs. selective professional devices

Over the past few months, many communes and intercommunal organizations have been organizing free trap distributions. You may have seen the news in your local newspaper or on your commune's social networks. The intention is good: to place as many traps as possible in the area to intercept the queens in spring. But not all traps are created equal. Far from it.

The typical communal trap is often a bottle model or a simple funnel trap. Low unit cost (sometimes less than €2), mass production, easy distribution at a public meeting or to the commune. The principle: an attractive liquid at the bottom, the queen enters attracted by the smell, and can't get out again. On paper, it works. In practice, these traps also catch flies, moths, wasps and solitary bees. In short, anything attracted by sugar. A study conducted by ITSAP (Institut de l'abeille) showed that some non-selective traps caught up to 90 % of non-target insects. It's a silent carnage.

A selective trap for the Asian hornet: what does this mean in practical terms? Several things:

• Inlet diameter. Holes calibrated at 9 mm let Asian hornets through (thorax approx. 8-9 mm), but block the larger European hornets. Smaller insects (bees, flies) can enter, hence the importance of the following point.

• Exhaust outlets. The best devices feature low openings of 5.5 to 6 mm, which allow small insects to escape, but not the Asian Hornet. This is the number-one criterion for choosing a trap worthy of the name.

• Color and shape. Research by the CNRS (Laboratoire Évolution et Diversité Biologique, Toulouse, France) suggests that dark traps are more attractive than light traps. Vespa velutina than transparent traps. Some manufacturers take this into account, others do not.

• The anti-drowning grid. Some professional traps place a grid over the liquid to keep the catch alive. The idea: check regularly and release non-target species. It requires monitoring, but it's the most respectful method.

The criteria for choosing a trap don't stop at design. Bait plays a decisive role. We'll come back to this in the next section, but keep in mind that dark beer alone, often recommended in municipal flyers, is not the most selective option. Mixtures based on cirier juice (aged apple juice) and white wine have been documented as less attractive to bees.

A professional selective trap costs between €15 and €35. A communal trap distributed free of charge means €0 for you, but often €1 to €3 for the public purse. The question is: is it better to use 200 basic traps in a commune, or 50 well-placed and well-monitored selective traps? The answer from most of the entomologists I have consulted clearly leans towards the second option. The volume of queen captures is not proportional to the number of traps set. It's the quality of the mesh, the positioning (close to known nesting areas, near apiaries, on the edge of woodland) and the regularity of monitoring that make the difference.

Some local authorities are beginning to understand this. In Nantes, Bordeaux and several communities in the Basque country, free distribution is now accompanied by short training courses on positioning and monitoring traps. This is real progress. If your commune offers this kind of support, go for it.

A successful trapping campaign: strategic recommendations and system limitations

You've got your trap. Good. Now you need to make it effective without turning your garden into an insect graveyard. Here's what we recommend at Pest Patrol, based on MNHN and FDGDON (Fédération des Groupements de Défense contre les Organismes Nuisibles) protocols.

Asian hornet bait is the key. Forget pure grenadine syrup or diluted honey: you'll attract all the bees in the neighborhood. Today's most recommended mix: one-third dark beer, one-third white wine (white wine partially repels bees), one-third blackcurrant or grenadine syrup. Some add a base of cirier juice (fermented apple). ITSAP has tested several combinations, and this one offers the best ratio of hornet attractant to bee repellent. Change the bait every 10 to 15 days at most, otherwise it will ferment too much and lose its effectiveness.

When to install, when to remove? The optimum window for spring trapping is between early March and late April, sometimes mid-May depending on the region. After this period, the surviving queens have already established their primary nest and are no longer searching for food in the same way. Continuing to trap in summer with the same set-up is counter-productive: you'll be catching mostly workers (who are permanently replaced by the colony) and non-target insects. Remove your traps in late April or early May.

Where to place the trap? Between 1.50 m and 2 m high, sheltered from the wind, ideally facing south or southeast to catch the morning heat. The most strategic areas: near an old nest spotted the previous year (queens often hibernate within a radius of 200 to 300 meters), near an apiary, on the edge of a hedge or forest border. Avoid placing it in the middle of a flower bed, as this will maximize the capture of non-target species.

Let's talk frankly about the limits of trapping. To date, no scientific study has demonstrated that spring trapping significantly reduces the number of nests in a given area. The Muller and Hérard report (2023) published by the MNHN is clear on this point: the density of founding queens is such that even intensive trapping only captures a fraction of the population. Out of 100 queens emerging from hibernation, only 1 to 2 % normally succeed in founding a viable colony. Competition between queens, climatic hazards and natural predation eliminate the vast majority of them, trap or no trap.

Does that mean trapping is useless? No. Trapping has real local benefits, particularly around apiaries, where it reduces direct predation pressure. It also makes it possible to monitor the progress of the species over a territory (it's a monitoring tool). And psychologically, for beekeepers who see their colonies decimated, every queen captured counts. But we mustn't expect miracles on a large scale. Protecting biodiversity also involves other levers: systematically destroying nests spotted in autumn, preserving habitats for natural predators, and research into biological control methods (promising work on a parasitic micro-fungus...), Beauveria bassiana, are underway at INRAE).

A crucial point that is often overlooked: report your captures. Take a photo, note the date and location, and transmit the information to the Asian Hornet platform (iNaturalist / Vespawatch). This data feeds monitoring models and helps scientists to calibrate control strategies. Your trap at the bottom of the garden is also a data collector for research.

Conclusion

Trapping Asian hornets in March remains one of the most accessible actions for private individuals who want to take concrete action. Take advantage of communal distributions if they exist in your area, but don't stop there: invest in a selective trap, use suitable bait, position it intelligently and, above all, remove it in good time.

Don't wait for your neighbor to do it. The queens are already out there. If you have any doubts about the identification of a captured insect, the choice of a device or the management of a spotted nest, contact a professional. That's what Pest Patrol is here for.

Frequently asked questions