The native tick Amblyomma variegatum is still one of the veterinary importance cattle tick in West Africa. It hinders the improvement of animal production through its negative impact on the health and reproduction of infested animals. Given their negative consequences on production quality and environmental health, chemical products use in the ticks control are increasingly discouraged.
Therefore, this study aimed to assess the acaricidal activity of essential oils of Ageratum conyzoïdes, Cymbopogon citratus, Cymbopogon giganteus, Lippia multiflora and Ocimum gratissimum against specimens of Amblyomma variegatum from Burkina Faso. For this purpose, the larval immersion test (LIT) was carried out to investigate the larvicidal activity of these essential oils. Likewise, gas chromatography-mass spectrometry (GC-MS) was performed to determine the chemical composition of each essential oil.
As results, the chemical composition was predominantly oxygenated monoterpenes for A. conyzoïdes (48.71%), C. citratus (99.9%) and C. giganteus (73.63%), whereas hydrocarbon monoterpenes was most present in O. gratissimum (63.7%) and hydrocarbon sesquiterpenes in L. multiflora (71.719%). The larvicidal activity recorded, varied according to the plant species and the dose applied. At the dose of 12.5 mg/mL, all of the studied essential oil, except L. multiflora (7.54%), induced 100% of larval mortality.
We highlight in this study promising larvicidal effects of local essential oils against A. variegatum. These essential oils can be used as bio-acaricides, an effective, environmentally-friendly alternative to chemical products. However, further investigations are needed on the mechanisms of action of these essential oils for in vivo experimentation and practical application in the control of A. variegatum ticks.
Essential oils, A. variegatum, Acaricidal activity, Chemical composition