Are you terrified by the Calabrian? You could avoid them dressing up with white or green: At least so suggests a study conducted by researchers from the University of Lódz in Poland. The compound eye of the hornet (Vespa Crabro) is able to distinguish shapes and colors And the research conducted by the Polish University shows that the degree of aggression is modulated also on the basis of coloring of the potential enemy. Despite being the largest Vespa in Europe, contrary to what is believed, the Calabrone is Less aggressive than other wasps and does not punish unless it comes disturbed Near the nest that tries to defend at any cost. To reduce the risk of puncture, we can also use some mosquito nets and the Higher Institute of Health recommends using opaque clothes and Eliminate garbage and sugary residues that attract them.
How a hornet is done and what attracts him at home
The Calabrone (Vespa Crabro), belonging to the family Vespidaeis the largest Vespa present in Europe: the queen measures about 35 mm, while males and workers have lengths between 20 and 25 mm. Very little if compared with the size of the Asian giant hornet (Vespa Mandarina), fortunately not yet present in Europe, whose queen can reach a length of 5 cm.
It is omnivorous, prey to other insects, feeds on invertebrates carcasses, but is also attracted to sugary substances contained in the fruits or in the nectar of flowers. Enter the house precisely because attracted by food residues or from very ripe fruit or because it is to Search for dark places And sheltered to build the nest.
Why does the hornet stings?
The hornet is less aggressive than other Vespids, but attacks if perceives a danger to the nest: It is a defense reaction. The nest, and therefore the colony, is the most precious good and must be defended at any cost. The hornets build large nests of consistency similar to paper, kneading cellulose with saliva. They are rather resistant by structure and are positioned in very repaired places, such as cavities of trees or holes in the walls.
Credits: Wikirigaou, CC By –a 3.0, via Wikimedia Commons
In the first attack against the intruder, the Calabrone issued by the poison bag placed near the stinger, not only the poison, but also A pheromone that immediately recalls other individuals: Basically call reinforcements! For this reason, the reaction to sting “the enemy” becomes mass. I am able to sting Only females And their smooth and retractable sting is not stuck in the victim’s skin. For this reason, Each hornet can sting several times. The puncture is painful, but no longer dangerous than that of other wasps unless you are allergic to the injected poison. The most common reaction is an intense, burning pain, swelling and redness in the affected area. In most cases, the situation is resolved in a few hours or a few days. In case of doubts, it is always good contact your doctor.
How to defend themselves and remove them: from the colors of clothes to classical methods
Polish research explains the relationship between the color of clothes and the risk of puncture. Of the researchers of the University of Lódz in Poland, over three years, they have located between August and September, in different areas of the city, crates containing Calabrone nests. Outside each box, identical balloons were positioned for size but of different colors (white, blue, green, brown etc ..).
The hornets were voluntarily disturbed, in order to induce them to go out to defend the colony. The view of the balloon led a defense reaction, but while dark balloons (black and brown) or bright colors such as orange have generated greater aggression, The color balloons white or green have not determined the attack Or they have induced a weak response from the hornets.
But there are some General precautions that we can adopt to reduce the risk of being points when you are outdoors, as recommended by the Higher Institute of Health:
- The hornet attacks if you feel in danger, so it is better to move slowly and avoid approaching nests
- prefer long sleeves and long trousers in the countryside, avoiding to stay barefoot;
- Go away from rubbish and sugary food residues, which could call the hornets;
- Avoid the use of very fragrant body products;
Even at home it is good to use mosquito nets And Remove garbage and food and fruit residues that attract the Vespids.
The fundamental role of the Calabones
Calabroni play the ecological role of “natural insecticides “ with the ability to attack and therefore regular various populations of insects that can be locally harmful for crops.
Also feeding on nectar contribute to the pollination and dispersion of seeds of some plants. These are social insects: in the spring the queens already fertilized in the autumn of the previous year, they leave the refuge where they have spent the winter and create new colonies by laying the first eggs from which sterile workers’ was born that begin to expand the nest. Between August and September The colony reaches maximum development, then at the beginning of autumn, in the last brood the queen produces males and females destined to be fertilized before going in diapause (a spontaneous arrest of the development of insects) with the arrival of the new winter.
