Academic Journal of Entomology 2 (1): 31-35, 2009 ISSN 1995-8994 © IDOSI Publications, 2009 Corresponding Author: S.A. Aina, Department of Plant Sci. and App. Zoology, Olabisi Onabanjo University, Ago-Iwoye, Nigeria 31 Efficacy of Some Plant Extracts on Anopheles gambiae Mosquito Larvae S.A. Aina, A.D. Banjo, O.A. Lawal and K. Jonathan Department of Plant Sci. and App. Zoology, Olabisi Onabanjo University, Ago-Iwoye, Nigeria Abtract: The efficacy of both the ethanolic and aqueous extracts of the fruits of Physalis angulata L. (Solanaceae); Xylopia aethiopica (Dunal) A. Rich (Annonaceae) and seeds of Piper guineense Schum and Thonn (Piperaceae); Jatropha curcas Linn. (Euphorbiaceae) were tested on the second instar larvae of Anopheles gambiae (L) at varying concentrations. With percentage mortality, P. guineense (83.33%) in ethanol was the most effective followed by its aqueous form (71.67%), P. angulata (36.94%) in ethanol, X. aethiopica (34.44%) in ethanol, J. curcas (33.06%) in ethanol, aqueous extracts of both P. angulata and X. aethiopica at 29.44% while the least active was J. curcas (20.56%) in water. On the basis of 24hrs LC values, P. guineense 50 (0.028 mg ml ) ethanolic extract acted most followed by its aqueous form (0.09 mg ml ), ethanolic extract of 1 1 P. angulata (2.5 mg ml ), ethanolic form of J. curcas (3.25 mg ml ), X. aethiopica (3.57 mg ml ) ethanolic 1 1 1 extract, aqueous forms of both P. angulata and X. aethiopica with 4.5 mg ml while the aqueous forms of J. 1 curcas (12 mg ml ) was the least active against the Anopheline larvae. For all the plants used, there were 1 significant difference among the ethanolic extracts and the aqueous forms. This could also make mosquito control in rural area become easier than before. Key words: Physalis angulata L. Xylopia aethiopica (Dunal) A. Rich Piper guineense Schum and Thonn Jatropha curcas Linn Anopheles gambiae (L) Ethanolic extract INTRODUCTION Scott et al. [4] also reported that the extracts from There are approximately 3,500 species of mosquitoes P. guineense and P. tuberculum (Jacq.) were effective grouped into 41 genera. Human malaria is transmitted against insects from five orders. All the three species only by females of the genus Anopheles. Of approximately contain isobutylamides, plant secondary compounds that 430 species of Anopheles, only 30-40 transmit malaria in act as neurotoxins in insects. The materials were nature [1]. considered safe for mammals because Piper spp. were The mosquito Anopheles gambiae is the used for centuries for spice and medicinal purposes. principal vector of malaria in Africa. According P. guineense oils also prevented the emergence of F to the latest WHO statistics, this parasitic disease brunchids of Callosobruchus maculatus [5]. Formulation infects from 300 to 500 million persons per year in the of 1% of essential oil of X. aethiopica was also said to be world and kills more than a million and a half each year, toxic on Sitophilus zeamais [6]. The seeds of J. curcas are mainly African children. Together with AIDS, malaria is considered antihelmintic in Brazil and the leaves are for one of the causes of mortality in the populations of fumigating against bed-bugs (Cimicidae). Also, the ether African, South Asia and Latin America; it contributes a extract shows antibiotic activity against Styphylococcus large part of the continued impoverishment of these aureus and Escherichia coli [7]. populations [2]. This study is carried out to know the effects aqueous Okorie and Lawal [3] tested the larvicidal properties and ethanolic extracts of these plants on larvae of of ethanolic extracts of fruits of P. guineense (African Anopheles gambiae (L) with a view to discover more plant black pepper) on larvae of Aedes aegypti (L) at different products that can be used to control the prevalence of concentrations. malaria fever in developing nations. three species of the plant family Piperaceae; P. nigrum (L), 1