Mosquitoes carry more than a hundred potentially fatal diseases including malaria, yellow fever,
dengue fever, encephalitis, filariasis and elephantiasis. Even today, they kill one person every twelve seconds.
Amazingly, nobody had any idea that mosquitoes were dangerous until the end of the nineteenth
century. In 1877, the British doctor Sir Patrick Manson – known as ‘Mosquito’ Manson – proved that elephantiasis was caused by mosquito bites.
Seventeen years later, in 1894, it occurred to him that malaria might also be caused by mosquitoes.
He encouraged his pupil Ronald Ross, then a young doctor based in India, to test the hypothesis.
Ross was the first person to show how female mosquitoes transmit the Plasmodium parasite
through their saliva. He tested his theory using birds. Manson went one better. To show that the theory worked for humans, he infected his own son – using mosquitoes carried in the diplomatic bag from Rome. (Fortunately, after an immediate dose of quinine, the boy recovered.)
Ross won the Nobel Prize for Medicine in 1902. Manson was elected a Fellow of the Royal
Society, knighted and founded the London School of Tropical Medicine.
There are 2,500 known species of mosquito, 400 of them are members of the Anopheles family,
and, of these, 40 species are able to transmit malaria.
The females use the blood they suck to mature their eggs, which are laid on water. The eggs hatch
into aquatic larvae or ‘wrigglers’. Unlike most insects, the pupae of mosquitoes, known as ‘tumblers’, are active and swim about.
Male mosquitoes hum at a higher pitch than females: they can be sexually enticed by the note of a
B-natural tuning fork.
Female mosquitoes are attracted to their hosts by moisture, milk, carbon dioxide, body heat and
movement. Sweaty people and pregnant women have a higher chance of being bitten.
Mosquito means ‘small fly’ in Spanish and Portuguese.