title: Fumigant toxicity of volatile natural products from Korean spices and medicinal plants towards the rice weevil, Sitophilus oryzae (L).
abstract: The fumigant toxicity of various volatile constituents of essential oils extracted from sixteen Korean spices and medicinal plants towards the rice weevil, Sitophilus oryzae L (Coleoptera: Curculionidae), was determined. The most potent toxicity was found in the essential oil from Mentha arvensis L. var piperascens (LC50 = 45.5 microliters litre-1 air). GC-MS analysis of essential oil from M arvensis showed it to be rich in menthol (63.2%), menthone (13.1%) and limonene (1.5%), followed in abundance by beta-pinene (0.7%), alpha-pinene (0.6%) and linalool (0.2%). Treatment of S oryzae with each of these terpenes showed menthone to be most active (LC50 = 12.7 microliters litre-1 air) followed by linalool (LC50 = 39.2 microliters litre-1 air) and alpha-pinene (LC50 = 54.9 microliters litre-1 air). Studies on inhibition of acetylcholinesterase activity of S oryzae showed menthone to have a nine-fold lower inhibitory effect than menthol, despite menthone being 8.1-fold more toxic than menthol to the rice weevil. Different modes of toxicity of these monoterpenes towards S oryzae are discussed.
authors.affiliation: Plant Protection Research Unit, WRRC, USDA-ARS, 800 Buchanan St, Albany, CA 94710, USA. sel@pw.usda.gov
authors.forename: S E
authors.initials: SE
authors.lastname: Lee
authors.forename: B H
authors.initials: BH
authors.lastname: Lee
authors.forename: W S
authors.initials: WS
authors.lastname: Choi
authors.forename: B S
authors.initials: BS
authors.lastname: Park
authors.forename: J G
authors.initials: JG
authors.lastname: Kim
authors.forename: B C
authors.initials: BC
authors.lastname: Campbell
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D001517:Coleoptera; D004336:Drug Antagonism; D005651:Fumigation; D007300:Insect Control; D007305:Insecticide Resistance; D007306:Insecticides / Q000633:toxicity; D007723:Korea; D019686:Lamiaceae / Q000737:chemistry*; D008610:Menthol / Q000737:chemistry; D009822:Oils, Volatile; D010946:Plants, Medicinal / Q000737:chemistry; D012639:Seeds / Q000469:parasitology; D017365:Spices; D013729:Terpenes / Q000737:chemistry
chemical_list: D007306:Insecticides; D009822:Oils, Volatile; D013729:Terpenes; D008610:Menthol; C019466:menthone; D000110:Acetylcholinesterase