Insecticidal activities of the ethanolic extract of citrus fruit seeds for the control of Culex mosquitoes

Abstract

Mosquitoes are among the significant vectors of public health concern. Culex mosquitoes have been implicated in spreading disease pathogens that inflicted both animal and man. The Hazards caused by using synthetic insecticide in controlling this vector cannot be overlooked. Thus, there is need to find alternative control method that is harmless and environment friendly. This research aimed to study the insecticidal activities of extract from four Citrus species seeds in the control of larval and adult stages of Culex mosquitoes. Different concentrations (1.0, 1.5, 2.0, 2.5, and 3.0%) of the extract was prepared using extraction solvent (ethanol) The highest percentage mortality of Culex larval was observed from application of 3.0% concentration of C. paradisi seeds extract within the period of exposure, 35.00%, 58.33%, 80.00%, and 100.00% larval mortality was recorded respectively. There is a significant difference (p < 0.05) comparing control and all the concentrations of Citrus seeds extract. Larvicidal potency of 3.0% seed extract concentration of C.sinensis, C.aurantium, C.aurantifolia, and C.paradisi are not statistically different (p > 0.05). The adulticidal potency of the seed oil varies with Citrus species. Citrussinesis seed oil gave higher percentage of adult Culex mortality in all the period of exposure. Statistically, the adulticidal potency of 2.5% concentration of all the Citrus seed oil are not different significantly (p > 0.05), expect the potency of C.aurantium seed extract. The lethal concentration requires for 50% (LC50) and 90% (LC90) of Citrus seeds oil extract varies with respect to period of exposure. Extract from Citrus seeds should be adopted for the control and management of insect vectors and it should be incorporated to integrated vector management (IVM) program.