Insecticidal properties of cymbopogon citratus and lantana camara oil against mosquitoes.

Abstract

Several methods have been used either chemically or naturally to reduce mosquito population with the aim of preventing the transmission of diseases caused by mosquitoes. However, the mosquito control methods should not cause harm to the humans and environment. This can be achieved by utilizing bio-mosquito repellants or insecticides formulated from different plant oils or extracts which are also cheap. Therefore this study was conducted to evaluate the insecticidal activities of the combination of Cymbopogon citratus and Lantana camara against mosquitoes to be used as repellants or insecticides. The study was conducted at Zoology laboratory and Ethnobotany laboratory at Makerere University. Different buckets with water were placed in the dark places for mosquitoes to lay eggs, the larvae were collected and taken to the zoology lab where they were reared till when they develop to adult mosquitoes. Fresh leaves of L.camara and C.citratus were collected from Nakifuma sub-county in Mukono district for extraction of the oils. The oils were extracted using steam distillation method. L.camara did not kill mosquitoes but repelled most of them (31.1%). C.citratus killed mosquitoes (86.7%) but also repelled them (70%). The combination of L.camara and C.citratus oil (50:50) killed highest number of mosquitoes (100%) and also repelled most of them (80.3%) compared with the individuals. Therefore the combination of L.camara and C.citratus oil (50:50) can be used in formulating bio-insecticide with both repellant and insecticidal activities.