title: Enhanced repellency of binary mixtures of Zanthoxylum armatum seed oil, vanillin, and their aerosols to mosquitoes under laboratory and field conditions.
abstract: The repellency of Zanthoxylum armatum seed oil (ZA-SO), alone or in combination with vanillin (VA), its six major constituents, and another four major previously known Zanthoxylum piperitum fruit oil constituents, as well as aerosol products containing 5 or 10% ZA-SO and 5% VA, was evaluated against female Aedes aegypti in laboratory and field studies. Results were then compared with those of N,N-diethyl-3-methylbenzamide (DEET) as a standard. Hand in cage laboratory tests showed that 0.2, 0.1, and 0.05 mg/cm2 ZA-SO resulted in > 92% protection through 30-min postexposure and was not significantly different than 0.05 mg/cm2 DEET. Skin treated with linalool and limonene (from Z. armatum) provided > 80% repellency to female Ae. aegypti at 10-min exposure, whereas cuminaldehyde, citronellal, geranyl acetate, and cuminyl alcohol (from Zanthoxylum piperitum) provided > 90% protection during this same time period. Only cuminaldehyde and citronellal provided complete protection comparable to DEET at 10-min postexposure. After that time, repellency of all plant constituents to mosquitoes was considerably decreased (< approximately 65%). An increase in repellency and duration of effectiveness was produced by a binary 1:4 mixture of ZA-SO and VA (0.05:0.2 mg/cm2) that was significantly more effective than 0.05 mg/cm2 DEET through 90 min. In field tests, an aerosol formulation containing 5 or 10% ZA-SO plus 5% VA gave 100% repellency at 60-min postexposure. Although these formulations were equal to the level of protection afforded by 10% DEET, repellency to the binary ZA-SO aerosol formulations at 90 min was significantly less effective than DEET. However, mixtures formulated from ZA-SO and VA merit further study as potential repellents for protection of humans and domestic animals from biting and nuisance caused by mosquitoes.
authors.affiliation: World Class University, Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea.
authors.forename: Hyung Wook
authors.initials: HW
authors.lastname: Kwon
authors.forename: Soon-Il
authors.initials: SI
authors.lastname: Kim
authors.forename: Kyu-Sik
authors.initials: KS
authors.lastname: Chang
authors.forename: J Marshall
authors.initials: JM
authors.lastname: Clark
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Ahn
mesh_terms: D000330:Aedes / Q000187:drug effects*; D000336:Aerosols; D000818:Animals; D001070:Appetitive Behavior / Q000187:drug effects*; D001547:Benzaldehydes / Q000494:pharmacology*; D005260:Female; D007302:Insect Repellents / Q000032:analysis* / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry; D012639:Seeds / Q000737:chemistry; D032106:Zanthoxylum / Q000737:chemistry*
chemical_list: D000336:Aerosols; D001547:Benzaldehydes; D007302:Insect Repellents; D010936:Plant Extracts; C100058:vanillin