Aromatic plants can provide potential alternative solutions to synthetic molecular currently used in the control of poultry ectoparasites because they are a rich source of bioactive chemicals. The purpose of this study is therefore to analyze the chemical constituents of the essential oil of H. suaveolens and to evaluate the insecticidal effect on lice parasite in chicken and turkey.
A gas chromatographic analysis (CG-FID) coupled with mass spectrometry (CG-SM) was carried out on the essential oil of the leaves of H. suaveolens and its bio-insecticidal activity was deduced from an inhalation test on adults of Lipeurus caponis, Menopon gallinae and Goniodes gigas exposed to increasing concentrations of 0.04 ; 0.08 ; 0.12 and 0.16 ÂµL cm-3 essential oil.
The results of this study indicate a high proportion of sesquiterpenic monoterpenic hydrocarbons (38.08%) (27.98%) and monoterpenic oxides (18.68%) with 1,8-Cineole or eucalyptol (12.11%) as major compounds; fenchone (11.81%); Î²-Caryophyllene (10.33%) and sabinene (7.18%). Insecticidal efficacy tests of H. suaveolens have shown a very interesting insecticidal power against its insects. High mortality rates were observed in the early hours of the experiment in M. gallinea. While the highest concentration (0.16 ÂµL.cm-3) induced only 100% mortality of adults of G. gigas and L. caponis after 4 hours of exposure.
This high toxicity observed would be strongly related to monoterpenic compounds, in particular 1,8-Cineole, known to have inhibitory actions on acetylcholinesterase, mono-oxygenases, octopamine or insect cytochrome P450.
Keywords: Hyptis suaveolens, Chemotype, Essential Oil, lice, poultry.