Science investigatory project
title: the effectiveness of citronella as an active ingredient in mosquito repellant soap
give 1 page of introduction and background
give the statement of the problem, formulation of the hypothesis, significance of the study, scope and delimination of the study, and definition of terms

 Oil of citronella comes from the lemongrass plant as an extract. As well as for perfume, it  has been found to be an effective repellant to mosquitoes and some other insects like lice. Research has confirmed its' mosquitoe repellant properties. It can also be effective in repelling Aedes aegypti or the dengue fever mosquito.).For maximum effectiveness it needs to be re-applied to the skin every 30-60 minutes. The US EPA confirms that oil of citronella has negligible or nil toxicity in use as a topical insect repellant, and no adverse effects when studied over a 60 year period. if label instructions are followed it is considered safe to people, including children. Citronella is native to tropical regions of Central and South America. The annual world production of oil of citronella is about 4000 tonnes.
The problem could be formulated to determine if oil of citronella ie effective as an insect repellant. The hypothesis would be that when oil of citronella is applied to the human skin, it can effectively repel mosquitoes. Studies have shown that oil of citronella repels mosquitoes and other insects rather than killing them. It was found from studies that it masks scents attractive to insects. As a result, the insects find it hard to find their target to feed on its' blood. Citronella oil is an essential oil extracted from the leaves and stems of  different species of Cymbopogon (lemonrass). 
The significance of these studies is to show that oil of citronella is mostly benign to the skin and also provides an effective repellant to insects including mosquitoes for a 30-60 minute period, thus providing relief to people such as geologists who work in mosquito infested areas like the Canadian Barren Grounds. The scope of these studies was to test for the repellancy of this natural product on key insects such as mosquitoes and lice. The delimination of the study was to mainly apply the oil to human skin and then introduce the mosquitoes and note their reaction to the oil. The term is mainly the definition of the oil above.