When the fine weather arrives, their inces-sant buzzing drives us mad. Throughout the world, a battle is waged against them… until man realises the utility of these tiny crea-tures.

To the great distress of many species living on our planet, mosquitoes have an insatiable thirst… for blood! And, like all haematophages (fleas, lice…) they are interested in blood alone. On every continent, these “serial biters” sow their terror. Sometimes just by causing a simple spot that will itch for several days, other times by transmitting dis-eases that are often fatal, such as those transmitted by the female Aedes mosquito or the female Anopheles mos-quito. In effect, only the female mosquito bites.

AQUATIC MOSQUITOS

Mosquitoes are most well known for their aerial acrobatics accompanied by that detestable buzzing caused by the beating of their wings, at the rate of 400 to 500 beats per second.
But we often forget that a mosquito spends the first half of its life under water… not as a mosquito of course, but in the larval state. An ideal means for it to begin life incognito. Flowerpots, puddles of water, air conditioning systems… any water-containing recipient will do, even though the larva needs to come up to the surface very often to stock up with air. But quickly, its thirst for blood betrays its true nature, and when the time comes, it will leave its “cocoon” to continue life as a winged mosquito.

MOSQUITOS LOVE SMELLY FEET

The mosquito is a finely tuned machine that chooses its prey with an astonishing precision. Attracted by certain colours and odours, the mosquito possesses a formidable sense of smell and exceptional eyesight that allow it to tar-get its victim. The numerous silky hairs on its head and its antennae serve as captors, enabling it to detect carbon di-oxide exhaled in respiration. So does this mean if you stop breathing the mosquito will not be attracted? No, because from 25 metres away, the approach is guided by vision. At-tracted by dark colours such as blue and black, the mos-quito activates the 500 facets that make up each eye and which give it a panoramic view of up to 220°. Finally, in the last few metres of its approach, the mosquito is in thermic mode: it detects the warm parts of the human body and can at last bite and feast itself. Sweat zones are therefore particularly attractive to mosquitoes, due to the lactic acid that the skin releases with sweat. Any physical effort, whatever it may be, can therefore lead to being bitten.

Other factors also attract these charming little creatures… vitamin B and cholesterol are two notable examples. But there is also a bacteria – Brevibacterium – that is common to cheese and smelly feet. Certain scientists like the Dutch professor Willem Takken have tested the effectiveness of strong odours (notably that of smelly feet) and of sweat in attracting mosquitoes. At the entrance to the tunnel are the mosquitoes, ready to attack. At the far end, in two com-partments, are objects with a more or less strong odour: socks, pieces of cheese, etc. By placing for example a smelly sock and a clean one, Professor Takken has been able to show quite clearly that the smelly one attracts mosquitoes. The Professor has repeated his experiments using the same test with a Dutch cheese, Limburger, and his own sweat…

WINGED VAMPIRES

The mosquito’s thirst for blood is insatiable. Dracula him-self is up against some serious competition. The mosqui-toes’ thirst is legendary: in the great Canadian north, close to 3000 bites per hour have been recorded in humans…
Biting victim after victim, the mosquitoes are capable of transmitting certain diseases. But what about the transmis-sion of HIV, the AIDS virus, by mosquito? Researchers are adamant: there is no risk of contracting HIV through a mosquito bite. First of all because it is estimated that there is only a one in ten million chance that the mosquito would pick up the virus while feeding on the blood of someone in-fected with HIV. And furthermore because the virus, once ingested by the mosquito, would have to resist its digestive process – but HIV is much too fragile. And lastly because for the virus to multiply, it would need to use the mos-quito’s cells, and these are not compatible with the devel-opment of AIDS.

MAN vs MOSQUITO, ENEMY BROTHERS

Whereas mosquitoes cannot transmit HIV, they are the formidable vectors of many other diseases around the world, such as malaria, which kills one human being every twenty seconds. So mosquitoes can do great harm, which prompts man to want to examine them more and more closely and notably to want to exterminate them.

But humans have also taken interest in the mosquito’s po-tential as a bacteriological weapon. In the 1950s, military scientists directed their attention to the subject. Though not very fruitful, these experiments confirmed that this idea could not become reality. In effect, although the mosquito is often a disease vector, it is unreliable as a bacteriologi-cal weapon.

NEW DISEASES, NEW RISKS

1999, the West Nile Virus phobia hits New York after sev-eral deaths are announced. Mosquitoes are among the first suspects.
The CIA takes over the affair, pronouncing several hy-potheses: a terrorist act (the mosquitoes could have been voluntarily infected with the virus in a laboratory); the pos-sibility of the accidental escape of the virus from the mili-tary base for bacteriological testing on Long Island; and fi-nally, the possibility that the mosquitoes were infected by a virus contained in the blood of tropical birds imported ille-gally into the United States.
Police and health services were mobilised to form a crisis unit to bring the situation rapidly under control: localising and destroying larvae, notably in vases in the tombstones of Bronx cemeteries, laying traps, etc.

In London too, the fear of the spread of new diseases transmitted by mosquitoes is enormous. The Underground in particular is under close surveillance. A mosquito, the Culex pipiens cavernicole, appears to appreciate the stag-nant puddles of water in the tunnels and unused corridors of the Underground. Scientists fear that this mutant mos-quito, after attacking rats and other creatures that crawl about these places, might transmit new diseases to hu-mans.

Mosquitoes also carry parasites responsible for terrible diseases such as elephantiasis (which remains a special case), an illness characterised by hard voluminous oe-dema, giving an appearance resembling an elephant.

Today the fatal disease most often carried by the mosquito remains malaria. Certain scientists estimate that with the tendency for global warming there could be a risk of the disease progressing towards certain zones of the Northern Hemisphere where medical services are sparse and which are being colonised little by little by the mosquito vectors.

PREPARATIONS FOR BATTLE…

In Singapore, faced with the propagation of new viruses and haemorrhagic fevers transmitted principally by the Aedes mosquito, the authorities have reacted by creating anti-mosquito brigades. Composed of police officers, the brigades track down the egg-laying sites that represent flowerpots, air conditioning systems (with water recovery) and other water points.

Any person who creates conditions favourable to the pro-liferation of mosquitoes is put on file by this great surveil-lance network and must pay a fine amounting to up to 1200 Euros.
Beyond the repression, this solution is also an excellent means of mapping the risk zones for mosquitoes. Its effec-tiveness is proven by the fact that the infested zones have been halved since the brigades were created.

In Quebec, even though mosquitoes carry no diseases, they still constitute a daily nuisance. The battle against the “maringouins” as they are called there takes diverse forms, from the most fantastical (anti-mosquito waves broadcast by the local radio) to the most scientific (extermination of the larvae by a bacteria, the Bacillus thuringiensis, the spreading of insecticide by aeroplane, helicopter or ground teams) not forgetting the most experimental (cannibal lar-vae, anti-mosquito fish, hormones, fungi).
Even if the absolute weapon does not exist, certain tech-niques have shown their effectiveness with encouraging test results: a fall in the mosquito count from 350 to 5 per minute in a treated zone.
In any case, the battle has a price, and the inhabitants of certain regions are nowadays required to pay an anti-mosquito tax.

As far as pharmaceutical remedies are concerned, the people of Burkina Faso also have their solutions against mosquitoes, the principal vector of malaria. Some have specialised in collecting and selling odorous plants that re-pel mosquitoes and cure the symptoms of malaria. Verita-ble “traditional therapy centres” have been set up. The cost of this traditional remedy is low, and as a result, shortages are starting to be felt.
All in all, one of the oldest, most effective and least oner-ous solutions remains the mosquito net…

THE MYSTIQUE OF THE MOSQUITO

Legends, rituals and ceremonies, cults and venerations… the mosquito travels through the ages and across conti-nents.

Japan : the mosquito show

Situated somewhere between legend and reality, the man-mosquito relationship is very special in Japan. During the Shogun era, a king proclaimed, in the name of tolerance, that the killing of mosquitoes was forbidden. At the Tosho-dai temple, the monks taught the giving of blood. The monks accepted mosquito bites fatalistically, repelling them only with fans.
Often personified by an invincible Sumo, the mosquito is also a central character in many stories of the traditional Japanese theatre, Kyogen.

Benin : the mosquito god

In Benin, the overabundance of mosquitoes has given rise to many legends that try to explain this often-murderous invasion. According to the historian Felix Iroko of the Uni-versity of Cotonou, the overabundance of mosquitoes is still explained in many villages by the wrath of the gods. Accordingly, invoking the gods and praying to them are seen as a means to persuade them to send the mosqui-toes away. So the people make masks to call on the god Babaalaba to chase the mosquitoes out of the region. Used in Gelede dances, these masks are sacred.

India : respect!!!

In India, the Jain community preaches non-violence. For the sake of the reincarnation chain, which dominates the Hindu religion, Jainists refuse categorically to exterminate mosquitoes. Respect for life applies also to these tiny crea-tures. Before drinking, they filter water to be sure not to swallow a mosquito or its larva; they check that there are no mosquitoes on a seat or cushion before sitting down, to avoid squashing one.
Representing 5 % of the Indian population, Jainists today use incense to repel mosquitoes, even though at one time tradition required certain masters to offer their bodies to bloodthirsty mosquitoes during an entire night.

Italy : world champion

The Italians have found the answer to a very simple ques-tion: how can you make mosquito-hunting fun? Quite sim-ply by creating the one and only world championship of mosquito fighting. The aim of the game is simple: to kill the most mosquitoes with your bare hands in ten minutes (the charming little insects are attracted by a lamp). The person who kills the most is proclaimed world champion, and may symbolically lay them to rest in a tiny coffin. The record to beat is 23 mosquitoes in ten minutes.

MOSQUITO AS NURSE, MOSQUITO AS GUINEA PIG

In the future, why not take advantage of the mosquito’s natural urge to bite us by turning it into a flying syringe? Certain scientists are currently studying this very subject.
In effect, it is envisaged that one day, mosquitoes could become frontline agents in the battle against malaria, by having them carry a biological agent against the parasite, which they would inoculate into humans by biting.
In the meantime, mosquitoes are giving their bodies to sci-ence and sometimes constitute excellent auxiliary diagnos-tic agents for identifying notably the viral or bacterial origin of diseases. The rapid multiplication of microbial colonies in their digestive tubes enables a more efficient identifica-tion of diseases.