如何减少蚊子
How to Cut Down on Mosquitoes
刘立军 供稿
TRANSCRIPT
Almost everyone who spends time outdoors has experienced mosquitoes. These bloodsucking insects give itchy bites and can spread disease.
Mosquitoes can spread viruses like West Nile, Zika, dengue and malaria. A 2021 report from the World Health Organization estimated that in 2020 there were 241 million malaria cases and 627,000 malaria deaths worldwide.
But there are things people can do to cut down on mosquitoes. You can make it harder for them to reproduce. And you can protect yourself.
Jessica Damiano is a gardening expert. She writes about outdoor living for the Associated Press. In a recent story, Damiano said the best control is prevention. In that story, she gave suggestions on how to cut mosquito populations where you live.
It may seem difficult to avoid mosquitoes. Some areas of the world are densely populated with them. People who live near bodies of water may experience more mosquitoes. But there are several measures you can take to reduce their numbers.
Mosquitoes need less than a centimeter of water to lay eggs. A female can lay hundreds of eggs at a time. So, check your property for standing water. Water can easily collect in small containers ― a child’s toy, a trash can lid, or a cooking pot.
Get rid of standing water, even if the amount seems small. Make holes in the bottoms of containers that can hold unwanted water.
Other sources of water such as in ponds and bird baths can be treated with chemicals.
Damiano suggests a bacterium called Bacillus thuringiensis israelensis or Bti for short. The bacterium is a safe and effective way to kill mosquito larvae. Several kinds of Bti are available. Each target different insects. So be sure to buy the one to target mosquitoes.
Bti also comes in several forms, including ring-shaped products called “Mosquito Dunks.” These rings float in water and offer 30 days of protection. Experts at the U.S. Centers for Disease Control and Prevention say mosquito dunks “will not harm people, pets and other animals,” and other insects, including honeybees.
You can also make your own mosquito trap. Put a handful of straw, hay, or grass cuttings into a dark-colored container filled with water. Let it sit for one to two days. Then add one mosquito dunk.
If you have many mosquitoes, place several containers around the area. Decomposing organic matter will attract the insects. They will lay eggs on the treated water. Every 30 days, change the water and add new chemicals to stop future generations of mosquitoes.
Mosquitoes also like overgrown plants. Keep your yard organized. Do not let plants grow too tall.
Running a fan at high speed will reduce mosquito activity. It works by simply blowing the insects away. Also, every time we breathe out, carbon dioxide from our breath attracts mosquitos. A fan can help get rid of our carbon dioxide quickly.
Damiano suggests avoiding chemical poison sprays. These can threaten helpful insects. These chemicals, she warns, only control a small part of the adult mosquito population. Also, she said, insect poisons need to be used several times in a season to work effectively.
Damiano says that so-called “mosquito plants” sold as mosquito repellents contain oils or chemicals that repel mosquitoes. But the plants do not keep mosquitoes away unless those chemical compounds are released, usually by crushing the leaves. Just having such a plant around will not help.
Some studies claim that citronella and lemongrass oil may provide some protection. But Damiano thinks this has not yet been proven. They may simply hide human scent.
There are other things you can do to protect yourself. Put screens in your doors and windows or keep them closed. Wear long clothing. And cut down on time spent outdoors between the early evening and the early morning. Mosquitoes are most active during that time.
Are mosquitoes all bad?
On the hunt to kill mosquitoes, you may ask yourself if they serve some purpose. Mosquitoes are pollinators, meaning they help some plants reproduce. And they are food for some animals, especially birds and bats. Also, some fish and turtles eat mosquito larvae. But Damiano says that getting rid of mosquitoes where you live will not harm the environment.
And that’s the Health & Lifestyle report.
I’m Anna Matteo. And I’m Jill Robbins.
VOCABULARY
1. larvae n.（昆虫的）幼虫，幼体（larva的复数）
2. mosquito dunks 杀幼虫剂（一种能杀死蚊子幼虫的细菌）
3. repellent n. a substance that is used for keeping insects away from you 驱虫剂
4. repel v. (formal) to successfully fight somebody who is attacking you, your country, etc., and drive them away 击退；驱逐
5. citronella n. a type of grass from which an oil used in perfumes and soap is obtained 香茅（香茅油用于香水和肥皂）
6. lemongrass n. 柠檬香草
QUESTIONS
Read the statements. Then listen to the news and decide whether the statements are true (T) or false (F). Then correct the false statements.
1. Almost everyone who spends time indoors has experienced mosquitoes.
2. Mosquitoes can spread viruses like West Nile, Zika, dengue and malaria.
3. Jessica Damiano is a gardening expert.
4. Damiano said the best control of mosquitoes is prevention.
5. People who live near bodies of water may experience more mosquitoes.
6. Mosquitoes need more than a centimeter of water to lay eggs.
7. The Bti bacterium is not a safe and effective way to kill mosquito larvae.
8. Mosquitoes like decomposing organic matter and overgrown plants.
9. Running a fan at low speed will reduce mosquito activity.
10. Mosquitoes are most active between the late evening and the early morning.
11. Getting rid of mosquitoes where you live will harm the environment.
KEY
Read the statements. Then listen to the news and decide whether the statements are true (T) or false (F). Then correct the false statements.
(F) 1. Almost everyone who spends time indoors has experienced mosquitoes.（正确表达）Almost everyone who spends time outdoors has experienced mosquitoes.
(T) 2. Mosquitoes can spread viruses like West Nile, Zika, dengue and malaria.
(T) 3. Jessica Damiano is a gardening expert.
(T) 4. Damiano said the best control of mosquitoes is prevention.
(T) 5. People who live near bodies of water may experience more mosquitoes.
(F) 6. Mosquitoes need more than a centimeter of water to lay eggs.（正确表达）Mosquitoes need less than a centimeter of water to lay eggs.
(F) 7. The Bti bacterium is not a safe and effective way to kill mosquito larvae.（正确表达）The Bti bacterium is a safe and effective way to kill mosquito larvae.
(T) 8. Mosquitoes like decomposing organic matter and overgrown plants.
(F) 9. Running a fan at low speed will reduce mosquito activity.（正确表达）Running a fan at high speed will reduce mosquito activity.
(F) 10. Mosquitoes are most active between the late evening and the early morning.（正确表达）Mosquitoes are most active between the early evening and the early morning.
(F) 11. Getting rid of mosquitoes where you live will harm the environment.（正确表达）Getting rid of mosquitoes where you live will not harm the environment.
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