73-476 AMERICAN ECONOMIC HISTORY: Mosquitoes
Common name for about 3000 species of two-winged insects consituting the
family Culicidae of the order Diptera. They are found from the Tropics to the
Artic and Antartic circles in nearly every part of the Globe. The mosquito is naturally
herbivorous but the female of several species acquires a taste for blood, and preys
upon animals and man. The salivary fluid of the insect contains a variety of
chemical agents including anticoagulants to prevent blood clotting, immunosuppressants
to keep swelling down in the victim, and vasodilators to open up the blood
vessels. The itching many people feel is an allergic reaction to the
saliva. Mosquitoes are known to be attracted by carbon dioxide and body heat
and also may be attracted by lactic acid and other body chemicals.
About 400 species of mosquitoes can
spread disease to humans. In particular, several bacterial and parasitic
diseases are spread by mosquitoes including malaria, yellow fever, dengue fever,
dengue hemorrhagic fever, encephalitis, and filariasis worm.
According to the World Health Organization at least 700 million people each year
are infected with disease by mosquitoes and that approximately 1 in 17 people
currently living will be killed by mosquito borne disease.
Their usual breeding grounds are swamps and
stagnant water.