Mosquitoes: Annoying but Amazing

李东

While the warm， sunny weather in Florida makes outdoor activities， such as picnics， swimming， parades， and sporting events， enjoyable， pesky mosquitoes may be lurking nearby eager to interfere with your fun. Mosquitoes are tiny little creatures that bite people， make them itch， and sometimes even transmit diseases. While mosquitoes are annoying and sometimes hazardous （有危險的）， they are also interesting little pests.

The “Little Fly”

Of all the insects， the mosquito is most similar to the fly. They both have wings， compound eyes， and three main body segments： a head， a thorax， and an abdomen. Basically， the mosquito is a skinny fly with longer legs and a tube for a mouth. In fact， the word “mosquito” is Spanish for “little fly”.

Don't let the name fool you， though. These “little flies” are highly advanced and specialized creatures. More than two thousand types of mosquitoes live in the world and they've been around for over thirty million years—far longer than humans. Over the millennia， mosquitoes have developed a wide range of abilities， which help them survive and make them difficult to outsmart.

Mosquitoes' greatest abilities are their acute sense， which they use to find food. Their main sensors specialize in detecting three things： chemicals， visual cues （color and motion）， and heat.

Mosquitoes can smell the chemicals that people and animals give off when they breathe and sweat. Mosquitoes can find these chemicals in the air from as far as one hundred feet away！ As they close in on their target， mosquitoes use their compound eyes to see motion and color. Then， at the closest range， they can sense the body heat of their intended victim. They can tell just where to go to find the best meal. Their three main sensors make them great hunters.

Once they find a source of food， they have a strange and famous way of eating—bloodsucking. They poke their tiny， sharp proboscises into people and animals and take tiny sips of blood. Don't worry about losing your blood， though. The amount a mosquito can drink is so small that you won't even notice it's gone.

Don't Scratch！

The most annoying thing about mosquito bites is that they itch. This itching is caused by anticoagulants， chemicals that the mosquito uses to prevent your blood from clotting. （The bug knows that if you blood dries quickly near the bite， it won't be able to drink any more.） You body reacts to the anticoagulants by swelling the area around the bite. The result is an itchy bump called a wheal. While the wheal is there， your immune system is busy cleaning away the anticoagulants.

Although people have an instinct to scratch mosquito bites， your doctor will tell you that this is not the best idea. Scratching can damage the skin or cause the bite to become infected. The best thing to do is to just wash a mosquito bite with soap and water and apply anti-itch medicine.

Mosquito bits are seldom dangerous but it is best to avoid being bitten whenever possible. Mosquitoes have been known to carry diseases that are harmful to humans and some people are allergic to mosquitoes and may become ill if bitten.

Beat the Bug

These persistent little pests are hard to beat， but there are several precautions which can help you avoid them. Since mosquitoes are most active during the morning and evening， you might try staying inside during those times of day. Put screens in your windows to keep them out of your house. If you do go out， wear extra clothing that covers your skin. This will make it harder for mosquitoes to bother you. Use mosquito repellents to confuse the insects' sense and make them pass you by.

You can also reduce the mosquito population. Mosquitoes lay their eggs in standing water， which is water that doesn't move or evaporate （蒸发）. Standing water might accumulate in buckets， barrels， and neglected swimming pools. You can help keep mosquitoes out of your neighborhood by getting rid of standing water.

Some scientists want to go even further to fight mosquitoes. At the veterinary Entomology's Mosquito and Fly Research Unit in Gainesville， Florida， scientists have found a new weapon called a baculovirus， a kind of tiny parasite （寄生蟲） found in dead mosquitoes in Florida. The scientists hope that this parasite could be used to kill the most harmful types of mosquitoes. Someday this amazing， annoying airborne pest may be controlled.

A） Choose the best answer.

1. What is the primary topic of the second paragraph？

A. A mosquito is a lot like a fly. B. The word mosquito means “little fly”.

C. A mosquito has a long tube for a mouth. D. Mosquitoes have three main body segments.

2. According to the article， what is the main reason you should avoid scratching mosquito bites？

A. You will cause a wheal. B. You might harm your skin.

C. You will make it itch more. D. You might cause it to spread.

B） Answer the questions.

3. How do mosquitoes find food？

4. According to the article， what are the author's ideas about preventing mosquito bites？