title: Efficacy of Plectranthus glandulosus (Lamiaceae) and Callistemon rigidus (Myrtaceae) Leaf Extract Fractions to Callosobruchus maculatus (Coleoptera: Bruchidae).
abstract: As part of on-going efforts to use eco-friendly alternatives to chemical pesticides, methanol crude extracts of Plectranthus glandulosus and Callistemon rigidus leaves were sequentially fractionated in hexane, chloroform, ethyl acetate, and methanol to establish the most active fraction(s) against Callosobruchus maculatus in cowpea. Cowpea seeds (25 g) were treated with 0.5, 1, 2, and 4 g/kg of extract to evaluate the contact toxicity and F1 progeny production of the beetles in the laboratory. Mortality was recorded 1, 3, and 7 d postexposure. P. glandulosus hexane fraction was more toxic than the other fractions recording 100% mortality at 4 g/kg, within 7 d with LC50 of 0.39 g/kg. Hexane fraction of C. rigidus showed superior toxicity, causing 100% mortality at 4 g/kg within only 1 d of exposure with LC50 of 1.02 g/kg. All the fractions greatly reduced progeny emergence, with C. rigidus hexane fraction being the best progeny inhibitor. Fractions of P. glandulosus and C. rigidus leaves had sufficient efficacy to be a component of storage pest management package for C. maculatus.
authors.affiliation: Department of Biological Sciences, Faculty of Science, University of Ngaoundere, PO Box 454, Ngaoundere, Cameroon dangayisipi@yahoo.fr.
authors.forename: Simon Pierre Yinyang
authors.initials: SP
authors.lastname: Danga
authors.affiliation: Department of Biological Sciences, Faculty of Science, University of Ngaoundere, PO Box 454, Ngaoundere, Cameroon.
authors.forename: Elias Nchiwan
authors.initials: EN
authors.lastname: Nukenine
authors.affiliation: Department of Biological Sciences, Faculty of Science, University of Ngaoundere, PO Box 454, Ngaoundere, Cameroon.
authors.forename: Lame
authors.initials: L
authors.lastname: Younoussa
authors.affiliation: Federal Biological Research Centre for Agriculture and Forestry (BBA), Institute of Stored Product Protection, Königin-Luise-Str. 19, D-14195 Berlin, Germany.
authors.forename: Cornel
authors.initials: C
authors.lastname: Adler
authors.affiliation: Department of Pharmaceutical Microbiology & Biotechnology, Faculty of Pharmaceutical Sciences, Agulu, Nnamdi Azikiwe University, PMB 5025, Awka, Anambra State, Nigeria.
authors.forename: Charles Okechukwu
authors.initials: CO
authors.lastname: Esimone
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000254:growth & development*; D007887:Fabaceae / Q000469:parasitology*; D007306:Insecticides; D027822:Myrtaceae / Q000737:chemistry*; D010572:Pest Control, Biological; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D031346:Plectranthus / Q000737:chemistry*; D012639:Seeds / Q000469:parasitology
chemical_list: D007306:Insecticides; D010936:Plant Extracts
keywords: Callistemon rigidus; Callosobruchus maculatus; Plectranthus glandulosus; contact toxicity; fraction