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Buzz off! Matthew DeGennaro Wants to protect you From mosquito bites.

You're sitting at a picnic table when you feel a tingle on your arm. A familiar itchy sensation starts spreading across your skin. You race to brush the culprit away, but you're too late: You've been bitten by a mosquito.

Mosquitoes thrive in warm weather. Most bites are just annoying, not dangerous. But some types of mosquitoes can spread diseases.

One such disease is called Zika. An outbreak of this virus began in French Polynesia in 2013. It causes flu-like symptoms in most people. But recently, it's been linked to more-serious health problems. Zika has spread to South America and the Caribbean. Officials want to keep it from spreading very far in the U.S.

Matthew DeGennaro is on the case. He's a mosquito researcher at Florida International University in Miami. He's one of many scientists working to protect people from mosquito bites.

Bloodsucking Bugs

More than 3,000 species of mosquitoes live around the world. To people, they're pests. But for fish, birds, and other insect-eaters, the bugs are food. Mosquitoes also pollinate plants as they fly from one to the next to feed on nectar.

Male mosquitoes survive on nectar alone, says DeGennaro. But females need a blood meal to reproduce. They're the ones that bite other animals.

DeGennaro works with a mosquito called Aedes aegypti (ay-EE-dees ah-JIP-tie). This species feeds off humans and can spread diseases like Zika. DeGennaro studies how the insects locate humans to bite.

"Mosquitoes find people by smelling them," says DeGennaro. From a distance, the insects can detect the carbon dioxide we breathe out. When they get closer, they smell body odor. Even closer, they sense heat from our skin. That's when they move in for a bite.

Fighting Back

The best way to stop mosquitoes from spreading diseases is to keep them from biting us, says DeGennaro. In mosquito-heavy areas, officials spray pesticides, chemicals that kill the insects. You can take steps to avoid getting bitten too (see Protect Yourself, right).

DeGennaro wants to learn precisely which chemicals from our bodies mosquitoes detect.

To do that, he changes certain genes, or units of inherited material, in mosquitoes in his lab. These genes control the insects' sense of smell.

DeGennaro then tests how well the altered insects find people. He places them in one side of a screened-off container and puts his arm in the other side. If the insects fly toward him, he knows they can still smell him. But if they don't, he knows the gene he changed is one that helps the insects find us.

Eventually, DeGennaro's research could lead to new repellents that ward off mosquitoes. He hopes that this, combined with other tactics, will keep the insects under control. "With some luck and hard work," he says, "we will find a way to make mosquitoes leave us alone."

Protect Yourself

Here are the best ways to avoid mosquito bites.

* Make sure your windows have screens to keep mosquitoes outside.

* Empty any standing water from outdoor pots and other containers. Mosquitoes breed here.

* Use bug spray with an insect-repelling ingredient like DEET. An adult should help apply it.

* Cover exposed skin with long-sleeved shirts, long pants, and hats.

Lesson Plan

BEFORE READING

1. Use a digital projector or whiteboard to show "Buzz Off!" on pages 8-9 of the digital issue to the class. Use the mask tool to hide the article's headline and captions. Ask:

* What insect is this? (a mosquito)

* Why do you think its abdomen is red? (The mosquito is feeding from a person, and its abdomen is filled with blood.)

2. Have students raise their hands if they have ever been bitten by a mosquito. (All students will probably raise their hands.)

3. Divide the class into small groups. Have the groups work together to answer the following questions:

* In what type of weather and during what time of day were you been bitten by a mosquito? (Most bites occur in warm weather at dawn or dusk.)

* What are the symptoms of mosquito bites? (red, itchy bumps)

* What are some ways you can prevent mosquito bites?(Some answers include using bug spray, keeping windows shut, and covering exposed skin.)

4. After about five minutes, have the groups share their answers with the class.

5. Explain that in addition to bothering people with their itchy bites, mosquitoes can sometimes spread diseases. For this reason scientists are researching better ways to protect people from being bitten.

AFTER READING

* Describe two ways that mosquitoes benefit other organisms. (Mosquitoes help pollinate plants and are a food source for insect-eating animals.)

* How do mosquitoes find people? (They detect the carbon dioxide that people exhale. They can also smell people's body odor and sense their body heat.)

* What is the goal of Matthew DeGennaro's research? (to determine which genes control mosquitoes' ability to detect people)

SKILLSSHEETS available at scholastic.com/superscience

Stages of Life (T5): Answer questions about a diagram showing the mosquito's life cycle.

What Do You Know? (online-only): Ask and answer questions about the text.

OBJECTIVE

Understand how scientists are studying mosquitoes to learn to prevent bites.

READING LEVELS

Print Edition:

Lexile 760

Guided Reading Level 0

Online Leveling Tool:

Lexile 570

Guided Reading Level J

STANDARDS

NGSS: LS3.A: Inheritance of traits

NSES: Reproduction and heredity: science as a human endeavor

Common Core: Reading Informational Text: 1.

Ask and answer questions to demonstrate an understanding of the text.

DIGITAL FEATURES: 'Zls scholastic.com /superscience

Video: Learn more about the bloodsucking insects.

Web Link: Read about mosquitoes and other pests: http:// pestworidforkids.org /pest-guide/mosquitoes

DIAGRAM SKILL

Name: -- Date: --

Stages of Life

In "Buzz Off!" (pp. 8-9), you read about a scientist who is researching ways to stop mosquitoes from spreading disease. The diagram below explains the four main stages of a mosquito's life cycle. The length of the life cycle can range from a few days to a month. Study the diagram, then answer the questions.

Mosquito Life Cycle

(1) After a blood meal, a female mosquito lays its eggs in standing water.

(2) Hundreds of eggs form a floating raft. Long wormlike larvae hatch

(3) Larvae live underwater, feeding on microorganisms and swimming to the surface to breathe. Larvae develop into pupae. from the eggs.

(4) Pupae rest underwater as they transform into adults. The adult mosquito emerges from the pupa's skin.

ILLUSTRATION BY KATE FRANCIS

1. What is a mosquito called when it first hatches from an egg?

--

2. What is the name of the resting stage in a mosquito's life when it transforms into an adult?

--

3. What does an adult mosquito do before it lays its eggs?

--

4. When temperatures are warmer, a mosquito's life cycle progresses more quickly. How might this affect the mosquito population in an area?

--

5. Mosquitoes need standing water to lay their eggs. What could you do to reduce the number of mosquitoes in your area?

--

ANSWERS

1. larva 2. pupa 3. The mosquito has a blood meal, or drinks blood from an animal. 4. A shorter life cycle would mean that more mosquitoes would hatch within a given time, and the population would increase. 5. Dispose of standing water. For example, around your house you could empty water from buckets, flower pots, kiddie pools, etc.
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Title Annotation:life science: cool science jobs
Author:Free, Kathryn
Publication:SuperScience
Geographic Code:1USA
Date:May 1, 2016
Words:1206
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