The potential of lemongrass oil Cympopogon citratus L. as repellent to mosquito Aedes aegypti L.

The mosquito is one of insect vector causing the serious disease of the human. One of the serious disease is Dengue Hemorrhagic Fever (DHF) because the morbidity associated with death of human. The vector of the disease is mosquito Aedes aegypti. The control method using chemical insecticide has been known as many negative effects for human as well as environment. To solving the problem the safety control method is needed. One of possible way is using bio-insecticide. Lemongrass is one of bio-insecticide was reported has repellent effect. The Repellent is the material that has an ability to protect human from mosquitoes bite. Repellent contains active ingredients that can interrupt mosquitoes ability to find their host. The pest repellent plant (PRP) as well as lemongrass have been utilizing as biopesticides for sustainable pest management.  On the other hand lemongrass also was utilized as biopesticide for some fungi (Tzortzakis and Economakis, 2017). However the repellent ability test of lemongrass for mosquito in Bali is luck information, therefore the ability test of lemongrass as a repellent is necessary.  The repellent activity test of essential oil of lemongrass was conducted from September 2013 until December 2013. The purpose of the experiment is in order to know the repellent ability of lemongrass oil to protect human from mosquitoes bite Aedes aegypti. Repellent contains active ingredients that can interrupt mosquito ability to find their host. The forearm of human volunteers was used as the repellent test. The several concentrations of lemongrass oil were designed to the treatment of the test. Ethanol was utilized as a solvent of the solution. The concentration of lemongrass oil were 0 % (only ethanol), 1 %, 2.5 %,  5 %, and 10 %. The different concentrations of lemongrass oil were applied thinly to skin on the forearm of the three volunteers. After application, hand of volunteer was placed in to rearing box of mosquito. The period of application is 30 min after application of  lemongrass oil, the observation was observed   from the first  landing or bite of mosquitoes  on  2 min until 30 min after application. In all concentrations of lemongrass have repellent ability, however in low concentration only keep the repellent activity sort time only 6 min after application. The 5 % of concentration of lemongrass oil have repellent ability more long time until 26 min after application, the data was collected base on the landing or bite of mosquito. On the other hand the 10 % of concentration of lemongrass sowing the 0 of mosquito landing on the skin of volunteers until 30 min after application.