Comparative repellency of 38 essential oils against mosquito bites.
The mosquito repellent activity of 38 essential oils from plants at three concentrations was screened against the mosquito Aedes aegypti under laboratory conditions using human subjects. On a volunteer's forearm, 0.1 mL of oil was applied per 30 cm2 of exposed skin. When the tested oils were applied at a 10% or 50% concentration, none of them prevented mosquito bites for as long as 2 h, but the undiluted oils of Cymbopogon nardus (citronella), Pogostemon cablin (patchuli), Syzygium aromaticum (clove) and Zanthoxylum limonella (Thai name: makaen) were the most effective and provided 2 h of complete repellency. From these initial results, three concentrations (10%, 50% and undiluted) of citronella, patchouli, clove and makaen were selected for repellency tests against Culex quinquefasciatus and Anopheles dirus. As expected, the undiluted oil showed the highest protection in each case. Clove oil gave the longest duration of 100% repellency (2-4 h) against all three species of mosquito.
Trongtokit
Yuwadee
Y
Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand. ytrongtokit@yahoo.com
Rongsriyam
Yupha
Y
Komalamisra
Narumon
N
Apiwathnasorn
Chamnarn
C
D000279:Administration, Cutaneous; D000330:Aedes; D000818:Animals; D000852:Anopheles; D003465:Culex; D009033:Culicidae; D035264:Flowers; D006801:Humans; D007299:Insect Bites and Stings / Q000517:prevention & control*; D007302:Insect Repellents / Q000008:administration & dosage / Q000627:therapeutic use*; D008517:Phytotherapy; D018515:Plant Leaves; D010938:Plant Oils / Q000008:administration & dosage / Q000627:therapeutic use*; D010946:Plants, Medicinal; D012639:Seeds; D016896:Treatment Outcome
D007302:Insect Repellents; D010938:Plant Oils