Insecticidal properties of essential plant oils against the mosquito Culex pipiens molestus (Diptera: Culicidae).
The insecticidal activities of essential oil extracts from leaves and flowers of aromatic plants against fourth-instar larvae of the mosquito Culex pipiens molestus Forskal were determined. Extracts of Myrtus communis L were found to be the most toxic, followed by those of Origanum syriacum L, Mentha microcorphylla Koch, Pistacia lentiscus L and Lavandula stoechas L with LC50 values of 16, 36, 39, 70 and 89 mg litre-1, respectively. Over 20 major components were identified in extracts from each plant species. Eight pure components (1,8-cineole, menthone, linalool, terpineol, carvacrol, thymol, (1S)-(-)-alpha-pinene and (1R)-(+)-alpha-pinene) were tested against the larvae. Thymol, carvacrol, (1R)-(+)-alpha-pinene and (1S)-(-)-alpha-pinene were the most toxic (LC50 = 36-49 mg litre-1), while menthone, 1,8-cineole, linalool and terpineol (LC50 = 156-194 mg litre-1) were less toxic.
Traboulsi
Abdallah F
AF
Faculty of Agricultural Sciences, Lebanese University, Beirut, Lebanon. abdallah@cyberia.net.lb
Taoubi
K
K
el-Haj
Samih
S
Bessiere
J M
JM
Rammal
Salma
S
D000080462:Acyclic Monoterpenes; D027926:Anacardiaceae / Q000737:chemistry; D000818:Animals; D000081008:Bicyclic Monoterpenes; D003465:Culex / Q000187:drug effects*; D000081005:Cyclohexane Monoterpenes; D003511:Cyclohexanols / Q000633:toxicity; D053138:Cyclohexenes; D000081007:Cymenes; D004347:Drug Interactions; D000077591:Eucalyptol; D008401:Gas Chromatography-Mass Spectrometry; D007306:Insecticides / Q000633:toxicity*; D019686:Lamiaceae / Q000737:chemistry; D007814:Larva / Q000187:drug effects; D019684:Magnoliopsida / Q000737:chemistry; D008610:Menthol / Q000633:toxicity; D039821:Monoterpenes / Q000633:toxicity; D027822:Myrtaceae / Q000737:chemistry; D010936:Plant Extracts / Q000633:toxicity*; D018515:Plant Leaves / Q000737:chemistry; D010938:Plant Oils / Q000633:toxicity*; D018547:Plant Stems / Q000737:chemistry; D013237:Stereoisomerism; D013729:Terpenes / Q000633:toxicity; D013943:Thymol / Q000633:toxicity
D000080462:Acyclic Monoterpenes; D000081008:Bicyclic Monoterpenes; D000081005:Cyclohexane Monoterpenes; D003511:Cyclohexanols; D053138:Cyclohexenes; D000081007:Cymenes; D007306:Insecticides; D039821:Monoterpenes; D010936:Plant Extracts; D010938:Plant Oils; D013729:Terpenes; D008610:Menthol; C016775:alpha-terpineol; D013943:Thymol; C073316:carvacrol; C019466:menthone; C018584:linalool; C005451:alpha-pinene; D000077591:Eucalyptol