title: Insecticidal activity of selected monoterpenoids and rosemary oil to Agriotes obscurus (Coleoptera: Elateridae).
abstract: Acute toxicities of three naturally occurring monoterpenoid essential oil constituents and the essential oil of rosemary were tested against late instars of Agriotes obscurus (L.) (Coleoptera: Elateridae). Both contact and volatile toxicities of thymol, citronellal, eugenol, and rosemary oil were determined. Also, phytotoxicity of these compounds was evaluated on corn germination and seedling development. Thymol had the greatest contact toxicity (LD50 = 196.0 microg/larva), whereas citronellal and eugenol were less toxic (LD50 = 404.9 and 516.5 microg/larva, respectively). Rosemary oil did not show any significant contact toxicity, even at 1,600 microg/larva. In terms of volatile toxicity, citronellal was the most toxic to wireworm larvae (LC50 = 6.3 microg/cm3) followed by rosemary oil (LC50 = 15.9 microg/cm3), thymol (LC50 = 17.1 microg/cm3), and eugenol (LC50 = 20.9 microg/cm3). Thymol, eugenol, and citronellal significantly inhibited corn seed germination and development, whereas rosemary oil had only minimal phytotoxic effects.
authors.affiliation: Faculty of Land and Food Systems, University of British Columbia, 2357 Main Mall, Vancouver, BC, Canada V6T 1Z4.
authors.forename: Ranil
authors.initials: R
authors.lastname: Waliwitiya
authors.forename: Murray B
authors.initials: MB
authors.lastname: Isman
authors.forename: Robert S
authors.initials: RS
authors.lastname: Vernon
authors.forename: Andrew
authors.initials: A
authors.lastname: Riseman
mesh_terms: D000818:Animals; D001517:Coleoptera; D007306:Insecticides; D039821:Monoterpenes / Q000633:toxicity; D009822:Oils, Volatile / Q000633:toxicity; D051381:Rats; D027542:Rosmarinus / Q000633:toxicity; D013943:Thymol; D003313:Zea mays / Q000187:drug effects
chemical_list: D007306:Insecticides; D039821:Monoterpenes; D009822:Oils, Volatile; D013943:Thymol; C053775:rosemary oil