Vol. 3, Issue 6, Part A (2016)
Influence of urbanization on the sensitivity of female adults of the Anopheles gambiae complex to essential oils of some plants from the Littoral region of Cameroon
Author(s): Patrick Ntonga Akono, Calvin Tonga, Pierre Michel Jazet Dongmo, Sevilor Kekeunou, Nadine Lopedji Tedongmo and Leopold Gustave Lehman
Abstract: This study determines the influence of urbanization on vector susceptibility to essential oils of some plants from Cameroon. Essential oils were produced from pericarp of ripe fruits Citrus and fresh leaves of Cymbopogon citratus, using a Clevenger-type apparatus. Analysis was made by gas chromatography or gas chromatography coupled with mass spectrometry. Sensitivity tests based on the WHO standard protocol were carried out on Ndogbong (urban area) strains of An. coluzzii and Logbessou (poorly urbanized area) strains of An. gambiae. Essential oils from C. grandis, C. limon and C. sinensis were rich in hydrocarbon monoterpenes (91.2%, 91.43% and 94.92% respectively) with limonene as major compound. The oil from C. citratus was rich in oxygenated monoterpenes (75.8%), mostly geranial and neral. Sensitivity tests showed that these essential oils have remarkable adulticide properties vis-à-vis the Logbessou strain of An. gambiae. They induced 100% mortality at 50 ppm (C. citratus) and 100 ppm (C. sinensis and C. grandis). However for equal doses, the Ndogbong strain of An. coluzzii proved less sensitive; only essential oil from Cymbopogon citratus resulted in total mortality of this mosquito strain. Urban environment probably reduces the sensitivity of Anopheles mosquitoes to essential oils with low toxicity. However, the essential oil from Cymbopogon citratus kept its toxicity vis-à-vis mosquito strains of both areas (50ppm) and should thus be considered in the design of national control programs against vectors.
Comparison of sensitivities of An. gambiae
to essential oils at 50ppm, based on their lethal concentrations (LC50
How to cite this article:
Patrick Ntonga Akono, Calvin Tonga, Pierre Michel Jazet Dongmo, Sevilor Kekeunou, Nadine Lopedji Tedongmo and Leopold Gustave Lehman. Influence of urbanization on the sensitivity of female adults of the Anopheles gambiae complex to essential oils of some plants from the Littoral region of Cameroon. International Journal of Mosquito Research. 2016; 3(6): 45-53.