Abstract

Malaria is a serious health problem in many African countries. The Anopheles gambiae mosquito which is the major vector for this disease has developed resistance against synthetic pyrethroids which are the main stay of insecticide treated bed nets. The development of insecticide resistance and side effects associated with synthetic pesticides has triggered intense research efforts towards natural products (for vector control) such as essential oils because of their efficacy and safety. In this study, larvicidal potential of essential oil from Zanthoxylum gilletii was evaluated against malaria vector mosquito, A. gambiae. The essential oil was extracted by hydro-distillation, and its chemical compositions determined by gas chromatography mass spectrometry. The oil was dominated by sesquiterpenes and monoterpenes which accounted for 38.30 and 34.00%, respectively. The oil showed good activity against A. gambiae and recorded LC₅₀ and LC₉₀ values of 57.73 and 140.24 ×10^-3 mg/ml, respectively. The results obtained show that the essential oil isolated from Z. gilletii is a promising mosquito larvicide.

Key words: Malaria, Zanthoxylum gilletii, essential oil, Anopheles gambiae, larvicidal activity