Abstract:

Background and objectives: This study reported on larvicidal effects on lemongrass and garlic essential oils against Anopheles gambiae s.s which are mostly causative agent of malaria. Mosquitoes are well known vectors for spread of vector-borne diseases affecting human being, mostly malaria and lymphatic filariasis, the use of synthetic insecticides is one of the major methods of vector control. However, synthetic insecticides are linked with a number of problems call for search and development of environmentally safe and low cost insecticides using innate sources. This study was done to evaluate the larvicidal effectiveness of lemongrass and garlic essential oils against anopheles gambiae sensu stricto.

Methods: The essential oils were collected from local market at market in Mwanza. These oils were used for larvicidal activity using WHO standardized procedures and guidelines for larvicidal test method under laboratory conditions using third instar mosquito larvae of Anopheles gambie s.s. under exposure of 24hrs, 48hrs and 72hrs lethal concentrations causing 50% and 95% mortality, LC50 and LC95 were determined by probit analysis using statistical program for social scientist version 17.0 (SPSS 17.0).

Result: Lemongrass and garlic essential oils were dose dependant and their p-value did not show any statistical significant difference. Overall mortality induced in time based observation showed that, mortality was time dependant with highest mortality in 72hrs but had no significant differences between observation hours.

Recommendation and conclusion: These result suggest that investigated essential oils had shown potential as larvicides against anopheles gambiae s.s and it could be useful lead in search for other plant derived larvicides products.