Equipped with poisonous venoms, a single sting from one of them can prove fatal to anybody allergic to wasp stings.
Regardless, multiple stings can also be enough to kill anybody who is not allergic to wasp stings.
Even if the stings do not kill, they can cause kidney and other organ failure, skin rashes, nausea, and vomiting.
The number of deaths caused by stings since this invasive species from South East Asia was first discovered in Europe are not readily available.
Also known as Vespa velutina, the insect is believed to have first arrived in Europe in a container of pottery at the port of Bordeaux in 2004.
An Asian hornet (Vespa velutina), also known as a yellow-legged hornet or Asian predatory wasp, is of concern as an invasive species in continental European countries including France or Spain.
First settling and spreading among the forests of Aquitaine, of which Bordeaux is the main city, it quickly spread to neighbouring regions via France’s network of rivers and other watercourses — before arriving in countries all around Europe, including Italy, Germany, Holland, Belgium, Spain, and Portugal.
It thrived on rising temperatures across the continent caused by global warming.
Added to that, their football-shaped nests — which are usually found in trees — are far bigger than those of native European hornets.
European hornets number a few hundred in each nest, compared to the several thousand that can be found in an Asian hornet’s nest.
Their principal target is honeybees.
They kill them by hovering over the beehive, and as soon as they see a bee returning to the hive, a hornet will swoop down, grab it, and decapitate it — before chopping off its limbs and then taking them back to feed them to their own children back at their nest.
Such attacks lead to bees staying inside their hive, too scared to venture out in case they fall victim to the same death.
It means the bees stop building up the food stored in their own nest, and they — in effect — starve to death.
The Asian hornet is of major concern in France and Spain. Experts suggest they are less likely to establish themselves in Ireland given the cooler and damper conditions here.
The number of hornet nests found in France went from just one in 2004, to 2,000 in the Bordeaux area in just two years, the French National Institute for Agricultural Research noted in 2009.
That was also the year when hundreds of hornets attacked a woman out walking with her baby in southwestern France.
While the baby was unharmed, the hornets attacked a person who came to the woman’s aid before they then attacked a number of onlookers with multiple stings. That incident came the same week that a primary school cleaner was attacked when she found and disturbed a nest on school grounds.
Since then, hardly a year has passed without a report about the hornets attacking people.
Last September, for example, a 77-year-old hiker died when the group she was with were attacked by hornets in Brittany.
They were on a hiking trail in Côtes-d’Armor when they spotted a hornets nest lying on the foot of a tree.
Hornets from the nest swarmed around the eight hikers, and repeatedly stung five of them.
A woman suffered a heart attack and died at the scene, while one of her companions ended up in an intensive care unit.
That attack came just a week after a resident in the town was also attacked by the same hornets, when he walked on the same path.
A month before the Asian hornet attacks in Brittany, a 42-year-old man died in the centre of the country when he and a friend disturbed a nest of European hornets and they stung him multiple times in his head.
Native to France, the European insects may be less likely to attack people than Asian hornets, but they too can be lethal.
Deaths have also occurred in Spain, where it is estimated — based on Spanish Society for Allergology and Clinical Immunology statistics — around three or four people die every year from stings.
Whether the deaths are all from Asian hornets is not clear.
Between the years 1999 to 2018, some 78 deaths were officially registered in Spain where the external cause of death related to contact with hornets, wasps, and bees.
This equated to an average number of 3.9 deaths per year during the 20-year period studied, reaching a high of nine deaths in 2018, according to a study by the Academy of Veterinary Sciences of Galicia.
However, the authors of Human Fatalities Caused by Hornet, Wasp and Bee Stings in Spain noted: “From a strictly medical point of view, there is no reason for the social alarm generated by the appearance of the Asian hornet in Spain.”
Nevertheless, the best advice if you see a hornet’s nest is to give it a wide berth from the moment you set eyes on it.
They are particularly sensitive to vibrations, and as a result, it is recommended that you stay at least three or four metres away from a nest the minute you spot it.
While this sensitivity may well act as an early warning system to alert them about potential dangers, scientists are already developing ways of destroying them by looking at the frequencies of the vibrations hornets make with their wings inside their nests.
They vibrate their wings for a variety of reasons, including regulating the temperature inside the nest and communicating with each other.
However, as the sound frequency of their vibrations is different to both honeybees and European hornets, it makes it easier to detect and destroy.