Home Sciences The killer wasp acts again in Spain with the arrival of heat

The killer wasp acts again in Spain with the arrival of heat


The Asian hornet (also called killer wasp), velutine vespathreatens the population and animals again with the arrival of heat. This invasive exotic species, which arrived in Spain 12 years ago, spread in the early years at an alarming rate. In fact, few places in Spain are completely free of this insect, whose bite can be fatal. However, another thing is that the entire country has a permanent presence of this species, which seems restricted to the north of the peninsula.

The number of deaths between 2019 and 2021 rose to seven in Spain. In 2019 there were three deaths in our country and in 2020, despite the confinement, another three. Galicia and Asturias add up to 100% of these deaths, since they are not in vain the autonomies most affected by this plague.

All of these deaths occurred when these people unintentionally got too close to Asian hornet nests. It is a very territorial species, which does not hesitate to defend its nest in case of being attacked.

It is estimated that this species causes up to 90% of all wasp stings in the areas where its presence is greatest. «Approximately 3% of the population suffers from allergic reactions widespread by the venom of wasps and bees, and the annual mortality rate is estimated at 0.08 per million inhabitants, which means that some three or four people could die each year from this cause», recently explained the president of the Hymenoptera Allergy Committee of the Spanish Society of Allergology and Immunology (SEAIC), Berta Ruiz.

How far has this wasp really come in Spain?

According to the portal avispasiatica.org, which updates the information on the presence of this species in Spain, the Asian wasp will have colonized the entire Peninsula, Ceuta, Melilla and the Balearic Islands by 2029. Only the Canary Islands would be left out of this invasion.

However, experts are divided on its true expansion in the Peninsula, because while some assure that all of it is already occupied by this insect, others point out that at the moment it remains confined to the north, possibly without reaching Zamora or, much less, Madrid. One thing is that isolated specimens are seen anywhere and at some time and another is that there are colonies firmly established throughout the territory.

Alfonso Balmori, a biologist from the Junta de Castilla y León, admits that a few years ago “the general opinion was that it would end up colonizing almost the entire Peninsula”, but that idea has been nuanced. “This species has quite strict climatic constraints to be able to expand its breeding area” with respect to the current distribution map.

Read:  Catalonia proposes to reduce its polluting emissions by "at least 15%" by 2025

“Although, of course, there are specimens of the species flying over a good part of the Peninsula, they do not settle down due to these climatic difficulties (especially the winter frosts in the northern plateau and the prolonged drought in the southern plateau)”, adds Balmori. “I don’t think this species can expand on the Peninsula much more than it already has,” he concludes.

The Madrid’s community, for its part, seems to endorse this thesis. The Department of the Environment indicates that “the presence of the Asian hornet has not been detected” there. “Furthermore, we highly doubt that there are areas of the plateau where these specimens are present, since, according to our information, they have not yet penetrated from the Cantabrian coast or from Galicia. Maybe you are already in the Bierzo area, but there is no news that it has entered the rest of León or Zamorafrom Galicia”, they add from the Madrid Community.

threat to bees

The killer wasp is also a real threat to bees, already affected by other enemies, such as pesticides or climate change. In fact, these wasps destroy entire hives.

According to the Center for Ecological Research and Forestry Applications (CREAF) “it is estimated that a single wasp can capture between 25 and 50 bees per day. They take advantage of their much larger size to instill fear and kill them with a jaw blow. They separate the body parts, join them in a ball and move them to the nest to feed their larvae. Once the workers have disappeared, they enter the hive and finish off the honey”.

In addition, this entity explains that “it is rapidly expanding throughout Spain thanks to its great capacity to reproduce and disperse new colony founders. With a single queen the nest is already developed, which may have up to 15,000 cells. If we consider that each foundress of a new nest can produce 500 new queens a yearit is understandable that the increase in their populations is so fast”.

The velutine vespa it expands through our country at a rate of 100 kilometers a year, from the north to the south, according to the portal avispasiatica.org. At the moment, the border of their advance guard would be located, according to said website, in the extreme south of Zamora and isolated areas of Extremadura. However, there are numerous sightings by citizens beyond these areas.

Two years ago, the Government of the islands The Balearic Islands announced that this autonomy was the first territory in Europe to eradicate the killer wasp, that despite being far from its area of ​​expansion, it had already established itself in Mallorca. However, avispasiatica.org believes that the Balearic Government “threw the bells on the fly” with too much haste and considers that it would be necessary to act with more “prudence”.

Read:  Humanity must protect 44% of the planet if it wants to save wildlife

“Caution, because there may be Asian wasps in Mallorca, either in the Serra de Tramuntana or in other inaccessible areas. And caution due to the experience we have in other territories where it seemed controlled and rebounded quickly, ”they point out.

How is the killer wasp?

The Asian hornet measures between 17 and 32 millimeters in length, is characterized by having a completely black thorax and black abdominal segments with a yellow trim. Only the fourth segment of the abdomen is completely yellow or orange. The head is black with a yellow or orange face, and the legs are brown with yellow tips.

They can build huge, spherical nests, with the entrance hole on the side, and in which the cells are not visible from the bottom. They are usually located in the upper areas of the trees (mainly on alders, chestnut trees, walnut trees, apple trees, cherry trees or eucalyptus trees), and sometimes even in protected areas of buildings, stairs, barns, etc.

Currently, there are several investigations underway aimed at fighting this species, some of them especially hopeful, based on biological control. But as long as there are no effective systems, trapping and nest neutralization are the only forms of control.

What to do if it bites us?

The stings are very painful, but no more dangerous than those of native wasps. Most of the people attacked present local symptoms, such as pain, redness and swelling in the area where the poison penetrates, which disappear in several days.

The affected area should be cleaned with soap and water, and ice or cold water applied. In the first moments, you can try to denature the components of the poison using heat on the sting.

In allergic people, symptoms such as generalized itching, rise in body temperature, drop in blood pressure, respiratory problems, cardiovascular problems, nervous symptoms, glottis edema, etc. may appear.

In cases of multiple bites, the poison inoculation can be very high and also cause general symptoms, such as fainting, intense headache, fever, etc. In these cases, the damage caused can be important, even if there is no previous allergy.

If general symptoms are observed after an attack, without losing your calm but urgently, you should call 112 or go to a medical center to receive the appropriate treatment, as these symptoms are very serious and can lead to anaphylactic shock. .


Environment section contact: crisisclimatica@prensaiberica.es

Previous articleQueen Letizia’s jewel dress for the gala dinner with Qatari royalty
Next articleA new cosmological model suggests the existence of a parallel universe