MAY
1996

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

05-23-96

Everyone Hates Mosquitoes

If an “America's Most Hated” list of insects existed, mosquitoes would surely rank at the top. It's not that mosquitoes are big. In fact, they are small insects, rarely more than one-quarter inch in length. They're not even particularly ugly insects. It's just that mosquitoes have the nasty habit of feeding on blood — sometimes human blood. As a general rule, we humans are somewhat possessive of our blood and take a dim view of sharing it with a mosquito.

The bad image of mosquitoes is due to more than their bloodthirsty ways. The vampire-like feeding habits of mosquitoes have made them ideal carriers of disease organisms. Such organisms include viruses, bacteria, roundworms and protozoans. Mosquito-borne diseases are a major world health problem and are estimated to kill more than 2 million people each year.

Historically, diseases carried by mosquito vectors have done much more than just cause human illness and death. These diseases have had a major impact on the history of the world. One such disease is yellow fever.

Yellow fever is caused by a virus and was introduced into the New World from Africa along with its vector, the mosquito Aedes aegypti. Yellow fever has long been associated with seaports, including Havana, Boston, New York and New Orleans.

Yellow fever takes its name from the yellowing of the skin in those affected. The disease was also known as yellow jack because yellow quarantine flags were displayed in towns where affected people lived.

It is this disease that was largely responsible for the failure of the French to complete construction of the Panama Canal. However, the United States took over the project following the departure of the French. By controlling the mosquito populations through sanitation, the threat of yellow fever was significantly reduced and the United States succeeded in the project.

Malaria also is carried by mosquitoes. In the Bible, the disease is described as burning ague. Other ancient writings describe a common disease as showing alternating fevers and chills, a good description of malaria. Hippocrates described the disease and associated it with proximity to swamps and marshes, even though he probably did not suspect that the relationship was due to mosquitoes.

Some historians hold that malaria more than any other single factor was responsible for the downfall of the great civilizations of Greece and Rome. Prior to the 20th century, the Mississippi Valley of the United States was a malaria-infested area. Like ancient people before them the Native Americans of the area also suspected a link with the fever to the swamps and the mosquito.

Longfellow, in Hiawatha, writes about the association and concludes the mosquito might be responsible in some way because he sang his war song. Correct insect; incorrect sex. It's the female mosquito that bites and therefore transmits disease organisms. That's a relief, otherwise we'd have twice as many mosquitoes to worry about!

 

Writer: Tom Turpin
Editor: Andrea McCann