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Marengo, the house for bees

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“The queens of Marengo in the world” is the slogan dedicated to bees and chosen by the Union of European Journalists and Communicators (Ujce) for the epilogue to the “Steli di Pace” award set up at the Marengo auditorium to celebrate the Unesco International Science Day for Peace and Development. Pollination by bees is crucial to protecting biodiversity: honey provides data on pesticide contamination. The Desaix park at Villa Delavo holds eight hives: the idea suggested by the councillor Maurizio Sciaudone (Province of Alexandria) continues the unarmed struggle undertaken to promote peace on the site already damaged by the militias.

“The democracy of bees” by Giuseppe Zicari –

A colony of bees forms what we can call a super-organism because there is a complex social organization. They are fascinating insects for their social behavior that is generated by a brain consisting of less than a million nerve cells (they stand in a pinhead). For comparison, the human brain contains about billions of neurons and at least 10 times more supporting cells (called glial cells). Bees can store and remember the time when food is available. In experimental conditions, bees rewarded at a particular hour on one nutritionist and at a different time in another learn to fly at the right time and at the right place. Voluntary removal without return of sick bees (altruistic suicide or social immunity) was also recorded.

As for their communication skills, they are able to communicate the location of flowers and water in the darkness of the hive using dances and vibrations. To communicate the interesting and distant places they use what has been called the dance of the abdomen: the bee on re-entry performs a movement of the shape of the number eight. During the straight stretch the abdomen vibrates with a pendulum movement (12-15 vibrations per second). It makes circles in which the longer the phase of movement of the abdomen, that is, the more the distance from the pollen or nectar source. The straight race can be considered a ritualized version of the flight that the other workers will have to do to go from the hive to the target. The angle to the Sun of the straight stretch allows to communicate the direction; bees perceive the position of the Sun even in the presence of clouds, through the polarized light that filters. The duration of the wagging walk (carried out in the dark and in perpendicular honeycombs) is proportional to the duration of the flight outside. A duration of one second of the oscillating movement of the abdomen represents an average of one thousand meters of flight. The angle of the walk in relation to the vertical line of the honeycomb represents the angle of the trip to the outside in relation to the direction of the Sun. There is a relationship between the intensity and duration of the dance and the richness of the site.

Among the interesting behaviors of the bees there is the swarming, that is the phenomenon during which a part of the worker bees remains in the hive and raises a new queen, while the others (at least 10,000 bees) fly away together with the old queen to create a new colony. The swarming bees initially gather in a cluster less than thirty meters from the hive, where they will stay at most for a few days. From this swarm hanging from a branch, several hundred bees will leave in search of a new home exploring even 70 km2. The fascinating mechanism of this process is the democratic selection of the best site for everyone. It is implemented as it were a collective real estate valuation of the site (eg cavity of a tree) that must have minimum characteristics such as to be able to convince the majority of the colony. The swarm has only a few days to make the choice and occupy a new nest. The time available to them is regulated by the stocks of honey they took from the old house before leaving (about 50% of the body weight of the swarming bees is formed by the honey ingested). The decision-making mechanism compares several options presented by different exploratory worker bees. Each one tries to convince the other bees and the option will be chosen that first will have passed a consent threshold. The bees engaged in exploration and dance can be between 2.8% and 5.4% of the total number, that is between 300 and 500 if the swarm is composed of 10,000 insects; it is the number of bees that actively promotes the debate. In a few hours or days a group decision is made on which the survival of all depends. Initially, each explorer bee will perform the dance indicating the direction of the potential nest discovered; however, if you observe all the dancing bees (or most of them) just before the swarming, you notice that they indicate the same direction. Some interesting observations have allowed to note that the number of bees that must be in favor of the site is at least 75 worker bees. That is, it is sufficient that at least 75 explorers have visited the site and have considered it suitable promoting it with dance so that the swarm moves in that direction (more or less 1% of the swarm). It is a kind of quorum. Before departure, bees warm their muscles for flight and emit a characteristic noise. The choice of the best site has been made and they are preparing for the collective flight that will take them to the occupation of a new home. In this dimension, bees can be seen as a single, few-pound collective intelligence. One possible lesson from this behavior is that promoting open and fair competition between different factions can be a good solution to the problem of having to choose from a scattered set of information available among a group of individuals. The dancers convince other women to visit the site, these returning, if they have positively evaluated the new site, will dance in turn to promote the same proposal. The more experienced bees will make a democratic choice, there is no leader and do not delegate important decisions to those who will not suffer the consequences. Interestingly, the group is organized in such a way that the deliberations of individuals in direct confrontation result in a widely shared collective reasoning, so as to reduce the likelihood of making bad choices. This method has exceeded the selection made in over 20 million years, that is, in the estimated lifetime of the bees. For a few decades, bees have faced a new and major obstacle, stemming from technological innovation in the military sector: pesticides. In particular, some insecticides, at very low concentrations (parts per billion in nectar or pollen), so small as to be difficult to determine, are able to compromise the behaviour of bees. They are so low doses that they are not able to kill the bee and, however, are also concentrations 10 or more times lower than those that can be recorded in the nectar. These concentrations are much lower than those to which bees can be exposed by feeding nectar from fields treated with some insecticides. At these very low doses there is a impairment of communication ability, the dance of the abdomen can no longer perform its function. In addition, bees reduce the ability to orient, lose olfactory memory and fly less. Individual exposed bees do not die, but in a few weeks or months the colony may collapse.

The ubiquitous and large-scale use of pesticides harms bees, but also impairs the ability of ecosystems to render services essential to the survival of the human species. No ecosystem is spared. We continue to underestimate the gravity of this voluntary pollution that enriches less than 10 large companies. This story highlights the struggle of a few against many, where temporarily few are winners, but at the end of the game all will be losers.
The French philosopher Montesquieu (1689-1755) wrote a concept on which we should reflect: “What is not useful to the swarm is not useful to the bee”.