In vitro acaricidal effect of Syzygium aromaticum and Cymbopogon citratus essential oil on engorged female of cattle tick Rhipicephalus microplus in Benin

Abstract

Ticks are external parasites of livestock and vector of several pathogens in infected animals. They lower production performances, which result in severe economic losses for breeders. So far a number of synthetic acaricide are used for the control of Rhipicephalus microplus. However, as a consequence of their extensive use, this tick specie has developed a resistance to the major classes of acaricide.  In order to limit resistance and reduce the invasion of this tick, we have evaluated the potential acaricide action of Syzygium aromaticum of Cymbopogon citratus essential oils and their mixture of engorged females Rhipicephalus microplus . The Adults Immersion Test carried out showed sensitivity of ticks to the extract of Syzygium aromaticum and Cymbopogon citratus essential oil: 100% mortality of engorged female was obtained at the highest concentration, 10mg/ml, for the two essential oils. The mixture of Syzygium aromaticum and Cymbopogon citratus oil induced 100% death at a concentration of 1.25mg / ml. The lethal doses 50, 90 and 99% of individuals was calculated. The highest oviposition inhibition rate (90.3% for Syzygium aromaticum and 60.7% for Cymbopogon citratus) was obtained at a concentration of 10mg/ml. However, no oviposition was seen from a concentration of 1.25mg /ml of the oil mixture. The results relevant to hatching reduction rate were similar. Hence, Syzygium aromaticum and Cymbopogon citratus essential oil mixture could be used as an alternative solution  in the fight against ticks.