title: Synergistic repellent and irritant effect of combined essential oils on Aedes aegypti (L.) mosquitoes.
abstract: This study was designed to compare the behavioral responses of Aedes aegypti to a single essential oil and to a mixture of two or three essential oils using an excito-repellency test chamber. Mixtures were prepared from essential oils extracted from Litsea cubeba (LC), Litsea salicifolia (LS), and Melaleuca leucadendron (ML). In general, the mixture of essential oils produced a much stronger escape response by Ae. aegypti, regardless of the test conditions. No significant difference in escape responses was seen when the mixture of oils was compared with a standard commercial product containing DEET. Greater contact irritancy was seen from mixed oils of LC and LS than with other mixed oils. Mixtures of LC and LS at 0.075% showed the highest synergistic action (65.5% escaped) compared to that with unmixed oil alone at the same concentration (LC/20% and LS=32.2%). In addition, mixtures of LC and LS at 0.075% demonstrated the highest non-contact repellency (62.7%) and showed a greater effect than the use of LC (20%) or LS (20.3%) alone. We conclude that mixtures of two essential oils show potential as active ingredients for mosquito repellents.
authors.affiliation: Department of Entomology, Faculty of Agriculture, Kasetsart University, Chatuchak, Bangkok 10900, Thailand.
authors.forename: Atirach
authors.initials: A
authors.lastname: Noosidum
authors.forename: Theeraphap
authors.initials: T
authors.lastname: Chareonviriyaphap
authors.forename: Angsumarn
authors.initials: A
authors.lastname: Chandrapatya
mesh_terms: D000330:Aedes / Q000187:drug effects*; D000818:Animals; D004357:Drug Synergism; D007302:Insect Repellents / Q000494:pharmacology*; D009822:Oils, Volatile / Q000494:pharmacology*
chemical_list: D007302:Insect Repellents; D009822:Oils, Volatile
keywords: Aedes aegypti; DEET; Excito-repellency; Litsea cubeba; Litsea salicifolia; Melaleuca leucadendron; essential oils; irritancy