Combinatorial Effect of Azadirachta Indica Seed Oil and Citrus Limon Peel Oil on Larvae and Adult of Mosquitoes

Abstract

Emergence of resistant mosquitoes to Insecticide-treated nets and Indoor residual spraying is a threat to global malaria eradication program.The aim of the study is to investigate the combinatorial effect of Azadirachta indica seed oil and Citrus limon peel oil against mosquito larvae and adults. Fruits of Neem plant and peels of Unripe Lemon were obtained. The peels and seeds were separately washed, dried and blended into fine powder. Oil was extracted from each powder using absolute alcohol and separated using Soxhlet extractor. Each of the oils was diluted with absolute ethanol to obtain 20%, 30%, 40%, 50% and 60% concentrations. Equal quantities of the oils were mixed together and diluted with absolute ethanol to obtain fortified concentrations of 20%, 30%, 40%, 50% and 60%. Five millilitres of each dilution was sprayed on adult mosquitoes and active larvae in a container of 100 millilitres of water and mortality rate calculated at 15 minutes interval for an hour. Complete mortality of adult mosquito (100% mortality) was recorded at 60 minutes when 50% of lemon peel oil was administered while the same mortality rate was recorded with 60% concentration of Azadirachta indica seed oil at 60 minutes whereas the same optimum mortality was documented with 50% concentration of the combined oil extract. The lemon oil extract produced a promising mortality effect on mosquito larvae and adult mosquitoes hence could be explored for use as an alternative insecticide. Also, the findings revealed no synergistic or antagonistic effect between the two oil extracts.