Effects of extracts of Peristrophe bicalyculata, Allium sativum and Zingiber officinale on mosquito larvae
Abstract
The problem of pollution, vector resistance to synthetic insecticides has led to the safe plant products being tested as pest control agents. The effects of extracts from Peristrophe bicalyculata, Allium sativum and Zingiber officinale on mosquito larvae and the percentage mortality and, LC 50 value were determined. The phytochemical screening of the active ingredients were
carried out. The ground P. bicalyculata leaves, A. sativum bulb and Z. officinale rhizomes were extracted with hexane, diethylether, ethanol and water using the soxhlet extraction method. The extract were separated from the solvent by solvent recovering method. A series of concentrations of the extracts ranging from 0.1 – 1.0 mg/ml were tested against early fourth instar
larvere of mosquitoes and their percentage mortalities and LC 50 values determined. All extracts showed various degrees of larvicidal activity to mosquito larvae at high concentration except water (aqueus) extract. The diethylether soluble extract of Z. Officinale showed very high larvicidal activity where 70% mortality was achieved at a concentration of 0.2mg/ml and had an LC 50 of 0.43mg/ml. The best lethal dosage (LC 50 ) for P. bicalyculata is that for hexane extract with a value of 0.49ml/m/. The extract of A. sativum did not show very high activity. Photochemical analysis showed the presence of tannin, and alkaloid, in P. bicalyculata, flavonoid, saponin and alkaloid in A. avitum and Flavonoid, steroid and alkaloid in Z. officinale. It is concluded that extracts from P. bicalyculata and Z. officinale can be used as environmental friendly insecticide to control mosquitoes at the
breeding sites.
carried out. The ground P. bicalyculata leaves, A. sativum bulb and Z. officinale rhizomes were extracted with hexane, diethylether, ethanol and water using the soxhlet extraction method. The extract were separated from the solvent by solvent recovering method. A series of concentrations of the extracts ranging from 0.1 – 1.0 mg/ml were tested against early fourth instar
larvere of mosquitoes and their percentage mortalities and LC 50 values determined. All extracts showed various degrees of larvicidal activity to mosquito larvae at high concentration except water (aqueus) extract. The diethylether soluble extract of Z. Officinale showed very high larvicidal activity where 70% mortality was achieved at a concentration of 0.2mg/ml and had an LC 50 of 0.43mg/ml. The best lethal dosage (LC 50 ) for P. bicalyculata is that for hexane extract with a value of 0.49ml/m/. The extract of A. sativum did not show very high activity. Photochemical analysis showed the presence of tannin, and alkaloid, in P. bicalyculata, flavonoid, saponin and alkaloid in A. avitum and Flavonoid, steroid and alkaloid in Z. officinale. It is concluded that extracts from P. bicalyculata and Z. officinale can be used as environmental friendly insecticide to control mosquitoes at the
breeding sites.
Full Text:
PDFRefbacks
- There are currently no refbacks.