At our latitudes, wasps are present almost exclusively during the summer season, usually from April to October, but become more evident from the end of July.
In the summer months the colony develops rapidly and the number of specimens increases exponentially.
In this period it is therefore easy to see them both outdoors and indoors, if they create their nest near the houses in attics, chimneys, bins and fixtures.
There are three main types of wasps in Italy, the Vespini – or vespule – the Polistini – vulgarly called “cartoon wasps” – and the Vespe Crabro – or bumblebees.
The wasp nest, called the honeycomb, is mainly made in the spring months; depending on the type of wasp that creates it, it has different characteristics.
The life cycle of wasps is annual: the fertilized queen founded the colony in late spring, after spending the winter in a sheltered place.
As the temperature increases, the colony grows, as does the number of workers, the sterile female wasps that materially build the nest. In summer, therefore, the nest reaches its maximum level of expansion.
At the end of the summer the males begin to appear, which have an exclusively reproductive function. At the same time the queen wasp stops secreting the hormone that makes the workers sterile, giving rise to new queen wasps.
Wasps are very territorial and become dangerous if you get too close to the nest.
When the wasp perceives a threat to the colony, it becomes aggressive and the probability of being stung, even by numerous individuals at the same time, is high.
Away from the nest they sting only if grasped or crushed, otherwise they move away without reacting.
Crushing a wasp is counterproductive, since this causes the release of a chemical signal that stimulates the aggressiveness of the other members of the colony.
Although bees and wasps are often confused, the two insects differ in many ways and behavior.
Wasps, unlike bees, do not pollinate, but are useful insects for their predatory activity, feeding on other insects.
Furthermore, unlike the bee that stings only once and then dies, a single wasp can sting several times.
When a wasp stings, it injects from its sting a small quantity of neurotoxic venom. In itself the amount of poison is too low to cause problems in an organism the size of a man, but some people may be more sensitive to the poison and this could cause allergic reactions and lead to anaphylactic shock.
Wasp nests should only be removed if they pose a real danger to people.
It is possible to use long-range spray treatments, but given the very high possibility of a sting or a series of stings, it is always better to rely on a professional who can intervene in complete safety.