title: Repellent activities of essential oils and monoterpenes against Culex pipiens pallens.
abstract: Essential oils of Eulcalyptus globulus, Lavender officinalis, Rosemarinus officinalis, and Thymus vulgaris were examined for their repellent activities against Culex pipiens pallens. All 4 essential oils effectively repelled adult mosquitoes on hairless mice. Essential oil of T. vulgaris (thyme) had potent repellent activity within the tested materials, with a protection rate of 91% at a concentration of 0.05% topical treatment. Thyme essential oil significantly extended the duration of protection until 3 bites by mosquitoes. With gas chromatography-mass spectrometry analysis, thyme essential oil was a rich source of 5 monoterpenes, including in descending order thymol, p-cymene, carvacrol, linalool, and alpha-terpinene. These 5 monoterpenes also were assessed to determine their repellent activities to the mosquitoes. alpha-Terpinene had a potent repellent activity with a protection rate of 97% at a concentration of 0.05% topical treatment. Additionally, carvacrol and thymol showed an equivalent level of repellency. A spray-type solution containing 2% alpha-terpinene was tested for its repellent activity against Cx. pipiens. This solution showed stronger repellent activity than the currently used repellent N,N-diethyl-m-methylbenzamide (deet).
authors.affiliation: Department of Life Science, Soonchunhyang University, Asan, Chungnam 337-745, Republic of Korea.
authors.forename: Won-Sik
authors.initials: WS
authors.lastname: Choi
authors.forename: Byeoung-Soo
authors.initials: BS
authors.lastname: Park
authors.forename: Sae-Kwang
authors.initials: SK
authors.lastname: Ku
authors.forename: Sung-Eun
authors.initials: SE
authors.lastname: Lee
mesh_terms: D000080462:Acyclic Monoterpenes; D000818:Animals; D003465:Culex; D000081005:Cyclohexane Monoterpenes; D000081007:Cymenes; D000431:Ethanol; D005052:Eucalyptus; D005260:Female; D007299:Insect Bites and Stings / Q000517:prevention & control; D007302:Insect Repellents; D027523:Lavandula; D008297:Male; D051379:Mice; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; D011092:Polyethylene Glycols; D011109:Polymethacrylic Acids; D011205:Povidone; D027542:Rosmarinus; D013729:Terpenes; D013943:Thymol; D046930:Thymus Plant
chemical_list: D000080462:Acyclic Monoterpenes; D000081005:Cyclohexane Monoterpenes; D000081007:Cymenes; D007302:Insect Repellents; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; D011109:Polymethacrylic Acids; D013729:Terpenes; C007210:4-cymene; C038300:methylmethacrylate-methacrylic acid copolymer; D013943:Thymol; D000431:Ethanol; D011092:Polyethylene Glycols; C018669:gamma-terpinene; C053775:rosemary oil; C073316:carvacrol; C018584:linalool; D011205:Povidone; C045718:lavender oil