FAQ

Frequently asked questions

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What happens with my report of a nest?

A step-by-step plan of what happens after reporting a possible yellow-legged hornet nest can be found here.

What is the status of my report?

After reporting, you will receive an email with the web link of your report. You can use this url to check the validation status of your report.

To do so, click on the web link in the received e-mail. The status is visible at the top right. These are the possible options:

  • Unknown: yet to be validated.
  • Accepted (automatically): Your sighting has been validated as Asian hornet by automatic image recognition, but not yet uploaded in Vespa-Watch database. Did you report a photo of a nest? Please contact vespawatch@inbo.be if this status does not change to ‘Accepted (with evidence)’ and activity ‘nest’.
  • Accepted (with evidence) and species Asian hornet: Confirmed as an Asian hornet nest and delivered to Vespa-Watch.
  • Accepted (plausible) and species Asian hornet: Confirmed as an Asian hornet nest and delivered to Vespa-Watch.
  • Cannot be validated (yet): Your report has been validated but essential info is missing (request for more info sent or posted as a comment to observation).
  • Report not available: Your report has been validated but there are serious doubts about the reliability of your report (request for more info sent or posted as a reaction to observation). You may have reported other things than animals or plants

Can I report a nest located in Brussels, Wallonia, or the Netherlands?

This Vespa-Watch platform only monitors nests in Flanders, so it does not cover nests located in Brussels, Wallonia, or the Netherlands. If you have a nest to report in:

Where do you organize eradication?

An overview of locations with organized eradication by Vespa-Watch can be found here.

Is eradication free?

Check the conditions for free eradication here.

Can I eradicate a nest myself?

We advise not to eradicate an Asian hornet’s nest yourself. A wasp will defend its nest if it feels threatened, so it is at its own risk to remove a nest. We always **recommend having this performed by a professional eradicator who have completed specialised training or the fire brigade which is at your own expense.

I have observed a wasp. What can I do ?

You can report an individual Asian hornet.These data are used for nest tracking. Release the wasp afterwards to avoid unnecessarily killing of native insects.

We advise against capturing or killing Asian hornet queens to prevent confusion with native species or accidental trapping in a trap. Therefore, you should not take any further action. However, you can remain vigilant for potential nests in and around your house. See the question “How does an Asian hornet nest look like?” to learn how to recognize them.

I see many hornets in/on my bush and suspect a nest, but don’t see the nest. What can I do?

Possibly, the hornets are attracted to the nectar of the flowers. In autumn, there are not many flowering plants present. As a result, Asian hornets sometimes flock to a single shrub such as ivy. As such, seeing a high number of hornets on ivy or another shrub does not mean there is a nest in the shrub. A hornet forages up to 2 km from its nest to gather food. So a nest is nearby. At the end of summer, a nest is very large (up to 1 meter in diameter) and has a paper shell. Tips for locating a nest can be found here.

If you find a nest, you may always report it. Any report of a nest is very valuable for monitoring the species.

I have seen a large wasp. Is this the Asian hornet?

No, because the European hornet is larger than the Asian hornet. The differences between these two species are further explained here. The European hornet is a native and beneficial species, and we recommend to let if live if there is no nuisance. In case of doubt about the species, always free every insect! This prevents native species that are important for our biodiversity from being mistakenly killed. Do you doubt about the species? You can identify it easily and quickly by using the app ObsIdentify.

There is a large wasp in my house. What should I do?

Report every possible sighting of an Asian hornet. These data are used for nest tracking. Release the wasp afterwards to avoid unnecessarily killing of native insects.

I have caught a wasp in a jar. What should I do?

Report every possible sighting of an Asian hornet. These data are used for nest tracking. Release the wasp afterwards to avoid unnecessarily killing of native insects.

Is it useful to capture queens with selective traps in spring?

We advise against capturing or killing Asian hornet queens to prevent confusion with native species or accidental trapping in a trap. Therefore, you should not take any further action. However, you can remain vigilant for potential primary nests in and around your house. These nests have a paper envelope and are about the size of a tennis or volleyball. If you find an embryonic nest, you can always report it to us. Preferably with a photo showing the wasp that built the nest, as different wasp species often build similar types of embryonic nests during this time of the year.

What is the difference between a wick bait station and a selective trap?

In a regular wasp trap or non-selective trap, insects drown. We discourage the use of this type of trap in all circumstances because it kills many innocent insects that are valuable for biodiversity.

A selective trap also aims to catch insects but has openings and exits of different sizes. This allows insects larger than the Asian hornet to normally not enter the trap. Smaller insects can normally always exit the trap.

A selective trap is:

  • Placed in the spring to capture queens before they can build a nest.
  • Placed in the fall near beehives to reduce the number of hunting hornets near the hives.

We discourage the use of selective traps:

  • To prevent confusion with native species or accidental trapping of them.
  • Because the effectiveness of this method has not been proven at the population level.
  • This method may potentially do more harm than good to our biodiversity.

If you still decide to use a selective trap, it is important to use it correctly and release other captured species in a timely manner. Place the trap out of direct sunlight and ensure that the insects do not drown in the lure. For example, by applying the lure to a sponge inside the trap.

Wick bait station allow all insects to be released unharmed. You can find instructions on how to make them here. We hang the wick bait stations near a suspected nest to monitor them. We regularly check if they are visited by hornets. After observing an Asian hornet on the wick bait station, we tag it to determine flight direction and time. When you map these on a chart, you can narrow down the search area for the nest.

I have observed a nest. What can I do?

When the nest is low to the ground, try to take a clear photo of the nest with the wasp clearly visible. Several species of wasps build similar nests low to the ground, then a photo of the wasp is needed for validation. Do always keep a distance of 5 m from a nest. Report the nest.

In case of emergency, it’s best to contact a private eradicator or the fire brigade.

How does an Asian hornet nest look like?

Spring

In spring, you can observe two types of nests.

On one hand, you may come across a nest high in the treetops. This is a remnant of a nest from previous year. However, there is no need for extermination because the nest is unoccupied and won’t be reused this year. It’s still useful to report these nests because we use your reports for species monitoring and research.

On the other hand, in spring, you can find embryonic nests in a sheltered location close to the ground (less than 4 meters high). These nests have a paper envelope and are about the size of a ping-pong ball. These embryonic nests are constructed in spring by a queen. Therefore, there is only one wasp present in these nests. You will also find several cells in these nests with larvae.

Summer

After the first larvae have hatched, there are not only queens but also workers present in the nest. From then on, the further expansion of the nest happens very quickly because the queen receives assistance from the workers. This is referred to as a primary nest.

By mid-summer, 70% of these primary nests relocate to a new location, high in a tree (more than 10 meters). In this case, we call it a secondary nest.

Autumn

As the leaves fall, nests of Asian hornet become more visible. You can now clearly see large paper nests hanging at the top of a tree. They have now reached a diameter of up to 1 m.

Winter

Nests are inactive, there are no hornets present inside. Eradiction is not necessary. Reporting them is still useful for research and monitoring.

Is a nest from the previous year reused?

No, a nest from previous year is not reused. Therefore, extermination is not necessary. However, it’s still useful to report these nests because we use your reports for species monitoring.

If a nest remains untreated, will there be more nests in the vicinity the following year?

If there was an untreated nest nearby last year, it is possible that queens are present in the area, attempting to build new nests. We advise against capturing or killing individual hornets, as they are often mistaken for native species. If you spot an active nest, you can always report it. This information is highly valuable for monitoring the species.

What is the difference between an active, inactive and eradicated nest? What can I do?

  • An active nest is one where hornets are flying around the nest. If it is a nest of the Asian hornet, report this nest. In case of acute danger, contact a private eradicator or the fire service immediately.
  • An inactive nest is a nest where there are no more hornets flying around the nest. Inactive nests are not reused; they create a new nest every year. As a result, this nest no longer poses a danger and it is therefore no longer useful to control it. If it is a nest of the Asian hornet, report this nest.
  • An eradicated nest is one in which one sprays poison against insects (insecticides) into the nest. The nest is left hanging so that returning hornets come into contact with the poison. A controlled nest should look inactive, with no more individuals flying around the nest.

I have a nest in my garden, can I carry out any pruning works?

If you have an active nest in your garden (e.g. on your garden shed, facade, in the hedge, …), it is recommended to stay 5 meters away from this nest. If you are pruning, this distance should be even farther away because the sound of a motor makes a nest very annoyed so they can attack more quickly. It is then best to stop these pruning activities and only continue when the nest has been eradicated.

When is it useful to actively search for nests?

It is useful to actively search for nests from June onwards. You can find information on how to locate nests here.

How can I locate Asian hornet nests?

You can find information on how to locate nests here.

I have observed a European hornet nest. What can I do?

The European hornet is a native and beneficial species. We recommend letting it live if there is no nuisance. In case of an immediate danger, it is best to contact a private exterminator to remove the nest.

Questions for professional eradicators

I’m interested in becoming an Asian hornet eradicator. Where can I get this training?

Inverde, VBI and BSBB are organising specialised training courses, given that exterminating an Asian hornet nest requires taking extra safety precautions.

How can I protect my hives?

Follow the advice from Honeybee Valley.