1. Adefolalu, F.S, Ogbadoyi EO., Ndams, I.S and Mann, A. (2019). Evaluation of repellent effect of extracts of Hyptis suaveolens and Ocimum gratissimum leaf on diptera (culicidae).

Abstract

The use of plant for mosquito repellents can serve as a reliable means to curb the problems of mosquito transmitted diseases and the resistance from synthetic repellents. The repellent activity of adult mosquito to extracts of n-hexane, acetone, ethanolic and 70 % methanol of HyptissuaveolensandOcimumgratissimum leaf were tested using World Health Organization (WHO) standard methods. Repellence was tested by exposing twenty five adult mosquitoes to extracts for 0.5 to 24 h. The extracts of the non polar solvents were more effective as repellents. Repellence by extracts of n-hexane O. gratissimum H. suaveolensleaf was highest over a period of 2 to 4 h than that of the extract of n-hexane H. suaveolensleaf. The standard repellent diethyl toluamide (DEET) gave 100 % repellent effect for a period of 4 h while 0 % repellent was recorded for the 24 h period. The H. suaveolensand O. gratissimum leaf therefore have the potential to be used in formulating mosquito repellents that are of lower cost and with lesser risk properties which will further benefit the local economy.