簡介Introduction
在本活動中，你會學習吸引蚊子的一些因素，並運用所學來製作一個誘蚊器。你可把誘蚊器放在家居或學校以捕蚊，這有助預防由蚊傳播的疾病。你通過本活動有機會展示創意、團隊合作性、解難技巧和溝通技巧。
In this activity, you will learn what factors attract mosquitoes and apply the knowledge to build a mosquito trap. The trap can be placed in your home or in the school for killing mosquitoes, thus helping to prevent infectious diseases transmitted by mosquitoes. You will have a chance to demonstrate creativity, team work, problem-solving skills, and communication skills.
背景知識Background knowledge
1.
滅蚊對疾病預防的重要性：
- 蚊是傳播瘧疾、登革熱、日本腦炎和寨卡熱的媒介。蚊首先叮咬受感染者，並一併把病原體吸入體內。當蚊叮咬其他人，便會把病原體傳播到他們的體內。
- 為了減低蚊媒傳染病的傳播，我們應清除蚊的繁殖地，滅蚊，以及避免蚊叮。
The significance of mosquito control measures on disease prevention:
- Mosquitoes are the vectors for malaria, dengue fever, Japanese encephalitis and Zika fever. The mosquito first bites an infected person and takes up the pathogens. When it bites a healthy person, the pathogens are transmitted to that person.
- To reduce the spread of mosquito-borne diseases, we should remove the potential breeding grounds of mosquitoes, kill mosquitoes, and avoid mosquito bites.
2.
認識吸引蚊子的一些因素：
The major factors that attract mosquitoes:
a. 二氧化碳
我們呼出的氣體中含二氧化碳。蚊能探測環境中二氧化碳濃度的變化。當蚊探測到環境中二氧化碳濃度增加，會移向二氧化碳的來源。
b. 體熱
蚊能探測體熱，並移向温血動物。蚊還能找出宿主身體最温暖的地方來叮咬。體温愈高之處表示該處有較多血液流經體表。
c. 汗和體味
人的皮膚和汗液中有某些化合物（例如乳酸）會吸引蚊子。細菌分解汗液會產生體味，體味亦吸引蚊子。
d. 深色
黑色或深色的衣物與環境的對比較大，這使蚊可較容易辨認到穿着深色衣物的宿主。
a. Carbon dioxide
We emit carbon dioxide through exhaled air. Mosquitoes can detect changes in carbon dioxide level in their environment. When mosquitoes detect an increase in carbon dioxide level in the environment, they will move towards the source of carbon dioxide.
b. Body heat
Mosquitoes can detect heat and move towards warm-blooded animals. They can find the warmest area of the host to bite. The warmest area means that blood is pumping nearer to the body surface.
c. Sweat and odour
Mosquitoes are attracted to certain compounds (e.g. lactic acid) present on the human skin and in sweat. Body odour also attracts mosquitoes, which is resulted from the breakdown of sweat by bacteria.
d. Dark colours
Black or dark-coloured clothing helps mosquitoes to distinguish the host from the environment due to large colour contrast.
活動Task
老師會把同學分成三至五人的小組。與組員合作設計和製作一個誘蚊器。設計誘蚊器時，要注意以下各項︰
Your teacher will divide the class in groups of three to five. Collaborate with your group members to make a mosquito trap. Remember that the mosquito trap:
- 誘蚊器能釋出二氧化碳或其他物質以吸引蚊子；
- 誘蚊器能捕獲和殺滅蚊子。
- should emit carbon dioxide or other substances to attract mosquitoes.
- should be able to trap and kill the mosquitoes.
設計誘蚊器Design the mosquito trap
1.
老師會提供紅糖和酵母。試以紅糖、酵母和自備的物料設計一個誘蚊器。列出你的設計所需的物料。
Your teacher will give you some brown sugar and yeast. Design a mosquito trap using brown sugar, yeast and any materials that are easily available. List the materials and the quantity that your group will use.
2.
繪畫並標示你的設計。扼要地描述製作誘蚊器的步驟。
Draw and label your design. Briefly describe your steps in making the mosquito trap.
3.
寫出設計誘蚊器時，所參考的資料來源。
Write the source(s) of any reference you used when designing your mosquito trap.
製作及展示誘蚊器Make the mosquito trap and communicate results
1.
經老師准許後，你和組員便可收集所需物料和製作誘蚊器。
After getting your teacher’s approval, you can collect your materials and make the mosquito trap.
2.
選擇一個地點放置誘蚊器。一星期後，點算誘蚊器所捕獲的蚊子數目。拍攝照片作記錄。
Select a venue to place the mosquito trap. After one week, count the number of mosquitoes trapped inside. Take photographs for record.
3.
在班上展示和介紹你的誘蚊器和結果。
Present on the design and mosquito count of your mosquito trap in class.
4.
老師會根據以下評核準則來評核你的表現。
| 評核準則 |
水平 |
| 優異 |
良好 |
平平 |
差劣 |
|
生物學知識的應用
|
4 | 3 | 2 | 1 |
|
解難能力
|
4 | 3 | 2 | 1 |
|
創新的設計
|
4 | 3 | 2 | 1 |
|
報告及演示
|
4 | 3 | 2 | 1 |
|
引用參考資料
|
4 | 3 | 2 | 1 |
|
整體水平
|
4 | 3 | 2 | 1 |
Your teacher will evaluate your work based on the following grading rubric.
| Assessment criteria |
Quality of work |
| Excellent |
Good |
Fair |
Poor |
Application of biological knowledge
- Characteristics of living organisms which attract mosquitoes
- Use of yeasts to produce carbon dioxide
|
4 | 3 | 2 | 1 |
Practical solution
- The mosquito trap can attract and trap mosquitoes effectively.
|
4 | 3 | 2 | 1 |
Innovative design
- Innovative use of extra materials and original design
|
4 | 3 | 2 | 1 |
Presentation
- Clear and well-organized oral presentation, proper use of scientific language
|
4 | 3 | 2 | 1 |
Reference acknowledgement
- Any references used are properly acknowledged.
|
4 | 3 | 2 | 1 |
|
Overall quality of work
|
4 | 3 | 2 | 1 |
5.
你可如何改善你的誘蚊器？
What modifications can you make to improve your mosquito trap?
問題Questions
1.
酵母用糖進行反應以釋出二氧化碳。寫出代表此反應的文字反應式。
Write a word equation to represent the overall reaction carried out by yeast to produce carbon dioxide using sugars.
2.
釋出二氧化碳的誘蚊器有甚麼優點和局限？
What are the advantage(s) and limitation(s) of the carbon-dioxide-emitting mosquito trap?
3.
解釋為甚麼在兩星期後誘蚊器會停止釋出二氧化碳。
Explain why the mosquito trap eventually stops emitting carbon dioxide after two weeks.
4.
雌激素亦會吸引蚊子。提出為甚麼懷孕婦女被蚊叮咬的機會較非懷孕婦女為高。
The female sex hormone oestrogen also attracts mosquitoes. Suggest why pregnant women have higher chances than non-pregnant women to get bitten by mosquitoes.
延展部分Extension
電子捕蚊燈能吸引並殺滅飛蟲。它配備光源（可見光和紫外光）以吸引昆蟲飛入電網。當昆蟲接觸到電網，電網的電流會使昆蟲死亡。然而，有研究發現這種捕蚊燈滅蚊的成效不顯著，因為紫外光不吸引蚊。
另一些種類的捕蚊燈能釋出二氧化碳，或以辛烯醇 (octenol) 等誘餌吸引蚊。人類的汗液和呼出的氣體都含辛烯醇。
學生可以搜尋關於不同種類捕蚊燈的資料，了解不同設計的運作原理、優點和缺點，然後嘗試改良自己的誘蚊器。
An electronic bug zapper, also called an electrical discharge insect control system, is a device which attracts and kills flying insects. A light source (both visible and ultraviolet light) attracts insects to an electrical grid. When the insects come into contact with the grid, the electron current that flows through the grid kills them. However, a study shows that this type of bug zapper is not effective in killing mosquitoes which are not attracted by ultraviolet light.
New types of bug zappers which emit carbon dioxide or use external bait, such as octenol, to better attract mosquitoes are now available. Octenol is a chemical found in human breath and sweat.
Research on different types of bug zappers and pay attention to their working principles, advantages and drawbacks. Armed with this knowledge, you can further improve your mosquito trap.
電子捕蚊燈An electronic bug zapper