title: Toxicity and repellency of Hoslundia opposita Vahl (Lamiaceae) leaves' essential oil against rust-red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae).
abstract: The insecticidal properties of Hoslundia opposita Vahl (Lamiaceae) leaves' essential oil (EO) against Tribolium castaneum were investigated using contact toxicity and repellency bioassays. Mortality progressed with exposure period and ranged from 61.13% observed at 24 h after treatment (HAT) to 88.86% at 168 HAT. The LT50 (lethal time for 50% of treated adults) of H. opposita EO against T. castaneum was 10.42 h. Application of EO at 20-30 μL/30 cm(2) caused significantly (P < 0.05) higher percentage repellency than what was observed in control, 10 and 15 μL/30 cm(2) at 1 and 3 HAT, with significant repellency at 24 HAT regardless of dosage. Repellency class increased with EO dosage, with class V observed at 30 μL/30 cm(2), regardless of exposure duration. The RD50 (repellency dose for 50% of treated adults) of 15.88 and 13.37 μL/30 cm(2) for 1 and 2 HAT, respectively, was significantly higher than 0.09 μL/30 cm(2) at 24 HAT.
authors.affiliation: a Department of Crop and Environmental Protection , Ladoke Akintola University of Technology , P.M.B. 4000 , Ogbomoso , Nigeria.
authors.forename: Samuel Adelani
authors.initials: SA
authors.lastname: Babarinde
authors.forename: Adeyemi Oluseye
authors.initials: AO
authors.lastname: Akinyemi
authors.forename: Lamidi Ajao
authors.initials: LA
authors.lastname: Usman
authors.forename: Adeola Foluke
authors.initials: AF
authors.lastname: Odewole
authors.forename: Abraham Opeola
authors.initials: AO
authors.lastname: Sangodele
authors.forename: Oluwaseun Olasupo
authors.initials: OO
authors.lastname: Iyiola
authors.forename: Oluwatoyin Deborah
authors.initials: OD
authors.lastname: Olalere
mesh_terms: D000465:Algorithms; D000818:Animals; D007302:Insect Repellents / Q000494:pharmacology*; D007306:Insecticides / Q000494:pharmacology*; D019686:Lamiaceae / Q000737:chemistry*; D009549:Nigeria; D009822:Oils, Volatile / Q000494:pharmacology / Q000633:toxicity*; D018515:Plant Leaves / Q000737:chemistry; D014231:Tribolium / Q000187:drug effects*; D048889:Weevils / Q000187:drug effects
chemical_list: D007302:Insect Repellents; D007306:Insecticides; D009822:Oils, Volatile