Acaricidal Effect of Foam Soap Containing Essential Oil of Ocimum gratissimum Leaves on Rhipicephalus lunulatus in the Western Highland of Cameroon

Abstract

Acaricidal effect of foam soap containing essential oil of Ocimum gratissimum leaves was tested on Rhipicephalus lunulatus in western highland of Cameroon. Five doses of essential oil (0.00; 0.04; 0.06; 0.08; 0.10 μl/g) with four replications for each dose were tested in vitro. Each replication consisted of 10 ticks in Petri dish with filter paper impregnated uniformly with the foam soap on the bottom. Four of those doses (0.00; 0.06; 0.08; 0.10 μl/g) in three replications were used in vivo. In this case, each replication was made up of 10 naturally ticks infested goats. Results of this study indicated that foam soap containing essential oil of O. gratissimum leaves is toxic to R. lunulatus. The in vitro mortality rate was observed to vary from 0 to 30.00% during the treatment with the controls as compare to 80.00% with the lowest dose (0.04 μl/g) on day 8 and 100.00% with the highest dose on day 6. Meanwhile, the in vivo mortality rate was observed to be 22.69% with control on day 8 after treatments whereas the highest dose killed 93.87% of the tick by this day 8. The LD50 of the foam soap containing essential oil was 0.061 μl/g for in vitro and 0.066 μl/g for in vivo on day 2. This indicates that this medicated soap is potentially highly efficient on this parasite.

Keywords: foam soap, essential oil, Ocimum gratissimum, Rhipicephalus lunulatus, Cameroon