Asian Predatory Wasp (Vespa velutina)

The vespa velutina, usually known as Asian predatory wasp, was detected near our zone in Gipuzkoa in 2010. But Iparralde’s beekeepers were suffering them, few months before.

Year after year, they keep expanding and they have already colonized the north of Spain. There are now at Galizia, Cantabria, Basque Country, Aragon, Catalonia… The experts doesn´t reject that in a near future the wasp will colonize the entire peninsula although this specie adapts better to a mild and wet weather, as in the north of Spain.

Since then, authorities, beekeepers and other organizations are fighting against this wasp, as it is an aggressive predator for the native honey bees.

The Asian predatory wasp comes from Asia and came into Europe in 2004. Apparently, they came on a container full off pottery or wood imported from China through Bordeaux harbor. The concern has been increasing since then.

In 2005, the French farmers raise the alarm when they saw how the Asian predatory wasp finished with de domestic bee in more than 38 departments.

It can get mixed up with the European hornet (Vespa crabro). It is native species. They have almost the same size, but the European hornet has the abdomen yellow and the trunk brown, like the legs. The Asian predatory wasp has the trunk black and the legs’ end are yellow. The abdomen is dark with a thin sash pale colored, and the distal part is yellow orange.

PROBLEMS

The arrival of the Asian Predatory Wasp is not a public health problem for humans as in described wasps’ attacks to humans, it has always been a human provocation.

The Asian Predatory Wasp is not more aggressive to the humans than other native hornets; and the risk of his bite is similar.

But it supposes a menace to the balance of our ecosystem, because is an invader specie that is seriously affecting to the population of common bees (Apis melifera). The Asian predatory wasp is a common bees’ predator. And the common bees are fundamentals to secure the pollination of the plants and fruit trees. It has negative effects too on local insects.

The wasps measure around 1’18 in and the queen, around 1’49 in.

They build the nest hanging on the trees, always higher than 10’9361yd height. Sometimes they can appear on the top of the buildings. They had ball size and are made of paper, with brown or cream colour. And when the nest reaches his maximum development they can measure 19’685 in width and 31’4961 in height. Each nest can contain over than 1.500 Asian predatory wasps.

They eat flowers and ripen fruits and they get the protein thought the insects that they capture. The Asian predatory wasp cuts the head and the stinger of the common bee and, later, it eats the bee or moves it to his nest. It is more aggressive than the native wasp.

BIOLOGICAL CYCLE

In February-March the queen wasps emerge from its place of hibernation and in April-May each queen starts the building of the nest and makes the first lay. Between March and May the queen wasps build small nests, about 1’9685 in, where they put its eggs.  They are primary nests and it is in the summer ending when each queen makes another nest, where he produces 200 new queens and between 1.500 and 3.000 laborer wasps. They are big size nests that are located at the top of the trees, and they are more difficult to locate and destroy.

When the laborer wasps are born they continue with the building of the nest and take care feeding the colony too.

On September the males and the new Queens are born. The Queen are impregnated and at the beginning of autumn, they leave the nest.

At the arrival of the winter, they look for a new place to hibernate.

In winter the founder mother-queen and the Asian wasps die and the abandoned nest is it not going to be used the next year.

DETECTION AND CONTROL

To control the Asian predatory wasps, these are what it is used:

- Commercial or homemade capture traps.

As bait, this is what it is use:  1 part of beer, 1 part of white wine and ¼ of blueberry syrup. You can add salt in summer to prevent fermentation.

- Nests destruction.

You can tell there is a nest in the vicinity wherever you capture an Asian wasp.

WHAT TO DO IN THE CASE OF WATCHING A NEST?

The citizens must inform where they have seen a nest, so the firefighters destroy it.

- Do not approach less than 16ft 4.85in from the wasps nest.

- Do not try to excite it and do not move the nest away.

- Get in contact with authorities (Municipal police, firefighters,…) telling the exact location of the nest.

CATCH CAMPAIGN

2014: 14 Asian Predatory Wasp

2015: 53 Asian Predatory Wasp