FAQ

Frequently asked questions

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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:

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. You can report a nest on vespawatch.be via deze link.

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

I have observed a wasp. Whan can I do ?

Currently, reports of individual Asian hornets are being monitored through waarnemingen.be. You can do this without registration via this link.

You can also report your observation using the ObsIdentify app. Here (Dutch) you can find more information and a link to the app. Go to de App Store or GooglePlay and download the updated ObsIdentify-app. In this webinar (Dutch) or this blog (French), you will find step-by-step instructions on how to use the app.

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.

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 via this page 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.

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 via this page. Any report of a nest is very valuable for monitoring the species.

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 via this page because we use your reports for species monitoring.

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.

What happens with my report of a nest?

After reporting, you will receive a list of recognized Asian hornet eradicators in Flanders. We validate your report, which may take a few days. We will notify you if it is indeed an Asian hornet nest.

Do you perform eradication?

No, we are a reporting center for monitoring the Asian hornet, but we do not coordinate eradication ourselves. After reporting, you will always receive a list of recognized Asian hornet eradicators in Flanders, who are specialized in eradicating Asian hornet nests. In the case of emergency, immediately contact a private eradicator or the fire brigade.

Is eradication free ?

No, nest eradication is not free. The government does no longer reimburse eradication costs.

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.

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.

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

Try to identify the species of wasp using the ObsIdentify app by Natuurpunt. If it’s not an Asian hornet, you can release the wasp. More information about different wasp species and how to recognize them can be found here. 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.

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

Try to identify the species of the wasp using the ObsIdentify app by Natuurpunt. If it’s not an Asian hornet, you can release the wasp. More information about different wasp species and how to recognize them can be found here. 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.

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

Specialized training for the removal of Asian hornet nests is offered by Inverde and VBI.

From 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.

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.