Repellent activities of essential oils and monoterpenes against Culex pipiens pallens.
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).
Choi
Won-Sik
WS
Department of Life Science, Soonchunhyang University, Asan, Chungnam 337-745, Republic of Korea.
Park
Byeoung-Soo
BS
Ku
Sae-Kwang
SK
Lee
Sung-Eun
SE
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
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