Connecting students to their world through natural history science


1. How did you choose your topic?

We realized that nowadays, the control and preventive campaign against Zika virus epidemic is an urgent matter due to its unpredictability and severity. (This caused an emerging debate on whether Olympic games should be taking placed in Brazil or not where the Zika reached pandemic level). Zika virus is primarily transmitted to people through the bite of an infected mosquito named Aedes aegypti, the same mosquito that spreads dengue and yellow fever, and has turned into an alarming epidemic recently. In the first five months of this year, there were five cases of infection which resulted in death. Zika virus does not have clearly characteristic feating, thus, is difficult to diagnose. Unborn children whose mother contracted zika are at high risk of developing micro cephaly syndrome. Microcephaly causes intellectual disability, physical impairnment, language delays, epilepsy, or even dwarf syndrome.

Until now, scientists haven’t found any effective vaccine against Zika, hence preventing Zika is still difficult. Therefore, in our opinion, the best way to control and prevention against Zika disease for the time being is to prevent getting bitten by mosquito – the subject of the epidemic transmission. Consequently our chosen topic research on lemon-grass (Cymbopogon citratus) –A common savory planted in Vietnam. Based on the folklore experience, this species is being used to repel mosquitos, insects and reptiles.

2. How did you conduct your research?

Research question: Can essential oil from lemongrass (Cymbopogon citratus) repel mosquitos?

Presume: Lemongrass essential oil can be used for repelling mosquitos

Set up:

  • An empty glassmade box having a cover lid
  • 40 adult mosquitos
  • A small essential oil bottle
  • 4 volunteers
  • A time clicker


  1. Release mosquitos in the glass-box and putting the lid on.
  2. Spray the essential oil of lemongrass into a small space in the right hand for testing allergy. Four volunteers who are free of allergy (essential oils) will be selected for further experiment.
  3. Each volunteer will put the his/her hand (without lemon grass essential oil sprayed) into the glass-box within 30 seconds, then count the number of mosquitos perch (bite) on hand then posting these numbers onto the work-sheet.
  4. Spray the lemongrass essential oil onto the right hand of each volunteer, then requesting them to put their right hand into the glass-box within 30 seconds for counting numbers of mosquitos perch (bite) on hand then posting these numbers onto the work-sheet.

3. How did you select your entry category and create your project?

  • We tried to display it in 2 ways: presentation and exhibition
  • By presentation: we prepared presentation documents by powerpoint to persuade the judges as well as prepared products for display and moreover, to make video-tape on the expansion of project with outputs in the future.
  • By exhibition: we gathered relevant information to form an exhibition-board about the scientific research with questions, variant tests, methodology to carry out research, figures obtained and accomplished outcomes.

4. How does your project relate to GNHD annual theme?

  1. We aim to illustrate the antagonism, one of the most important but offer overlooked relationship in nature. In particular, the susceptibility inhibition relationship can be illustrated by the research on the effectiveness of mosquitoes repellent by lemon grass essential oil.
  2. In the progress of evolution and natural selection, some plants have evolved high adaptability, especially grass species, in some of these species have aromas (essential oils) in parts not only to attract pollinators but also to defend against their natural enemies, insects which are harmful to them. Lemongrass species is a vivid example proving capability to constraint the growth and development of mosquitoes. This process has been discovered and people used lemon grass to repel mosquitoes. It becomes an effective method to prevent and control Zika disease as well as other infectious diseases caused by mosquitoes. In the natural world, the relationship between the living organisms interact, and between human nature so well, very closely with each other.


- Team 3 Written Material English