Bioactivity of essentials oils of Hyptis suaveolens (L.) on the reproductive parameters of the Rhipicephalus (Boophilus) microplus

Abstract

The chemical composition of three essential oils of Hyptis suaveolens was performed by gas chromatography coupled with mass spectrometry and their bioactivity was deduced from a multi-dose immersion test in increasing progression. The results show that the essential oils of H. suaveolens analysed are of two types: a sesquiterpene- dominant type (51.86%) very rich in β-caryophyllene (20.69%) and a monoterpene-dominant type (38.08%) which is distinguished from the first by a relatively high eucalyptol (1.8-Cineole) content (12.11%). Laboratory tests indicate a high toxicity of the β-caryophyllene chemotype on females of R. (B.) microplus. Only gorged females exposed to the two concentrations (1% and 2%) of this oil laid eggs with a laying delay of 168 hours. The egg laying inhibition rate recorded for these two concentrations is 65 and 98% respectively. The essential oil of H. suaveolens therefore represents a very interesting alternative to the use of synthetic antiparasitic.