Insecticidal activity of the medicinal plant, Alstonia boonei De Wild, against Sesamia calamistis Hampson

Insecticidal activity of the medicinal plant, Alstonia boonei De Wild, against Sesamia calamistis Hampson 1 first-author 1 2 Department of Zoology, Ambrose Alli University, Ekpoma, Edo State, Nigeria Department of Zoology, Ambrose Alli University, Ekpoma, Edo State, Nigeria International Institute of Tropical Agriculture, Cotonou Station, Cotonou, Republic of Benin International Institute of Tropical Agriculture, Cotonou Station, Cotonou, Republic of Benin The bioactivity of the aqueous extracts of the leaf and stem bark of the medicinal plant, Alstonia boonei De Wild (Apocyanaceae), against the pink stalk borer, Sesamia calamistis Hampson (Lepidoptera: Noctuidae) was studied in a laboratory bioassay. The extracts were incorporated into artificial diet at a rate of 0.0% (control), 1.0%, 2.5%, 5.0%, and 10.0% (w/w). Both extracts significantly ( P < 0.01) reduced larval survival and weight in a dose dependent manner. The concentrations that killed 50% of the larvae (LC 50 ) for the stem bark extract were 2.8% and 2.1% at 10 and 20 DAI (days after introduction), respectively, while those for the leaves extract were 5.6% and 3.5%. The weights of the larvae also varied significantly ( P < 0.05) between the treatments in a dose dependent manner. We conclude that both leaf and stem bark extracts of A . boonei are toxic, used as growth inhibitors to S . calamistis larvae, and hold good promise for use as alternative crop protectants against S . calamistis . Alstonia boonei Extract Sesamia calamistis Toxicity Growth inhibitors INTRODUCTION 1 Alstonia boonei De Wild (Apocyanaceae) is a medicinal plant used extensively in West and Central Africa for the treatment of malaria, fever, intestinal helminthes, rheumatism, hypertension, etc. (Terashima, 2003 2003 ; Betti, 2004 2004 ; Abel and Busia, 2005 2005 ). The major phytochemicals in the stem bark are saponins, alkaloids, tannins and cardiac glycosides (Fasola and Egunyomi, 2005 2005 ). Despite its popularity as an aromatic plant, the insecticidal potential of A . boonei has not been investigated as has been done for other medicinal plants like neem, Azadirachta indica A. Juss (Maala et al., 2000 2000 ; James et al., 2003 2003 ; Bruce et al., 2004 2004 ). The objective of the present study was to examine the insecticidal properties of the aqueous extracts of the leaf and stem bark of A . boonei against the pink borer, Sesamia calamistis Hampson (Lepidoptera: Noctuidae), a major pest of maize and some other cereals in West and Central Africa (Bosque-Perez and Mareck, 1990 1990 ; Kfir et al., 2002 2002 ). MATERIALS AND METHODS 1 Fresh leaves and stem bark were collected once from A . boonei trees (about 15~20 m tall) along the Akure-Ifon Road, Ondo State, Nigeria, between October and December, 2005. This is the beginning of the dry season when the plant flowers and produces seeds. It is expected to have high concentration of secondary metabolites during this period. The leaves and stem bark were sun dried and ground to powder with an electric blender (SuperMaster®, Model SMB 2977, Japan). About 250 g each of the powders were extracted in the cold with about 300 ml of water in 1 L Schott Duran bottles for 72 h. The extracts were filtered through Whatman No. 1 filter paper and the extraction was repeated twice for maximum yield. The extracts were evaporated to dryness in a Gallenkamp Hotbox oven at 40 °C and kept in sealed glass vials until needed. The bioassay was done in the Insect Rearing Unit of the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. The dry extracts were incorporated into artificial diet for S . calamistis , made from cowpea and wheat germ flours (Jackai and Raulston, 1988 1988 ), at a rate of 0.0% (control), 1.0%, 2.5%, 5.0%, and 10.0% (w/w). The treatments were dispensed into wells of a plastic tray (Bioserv®) and allowed to cool down and solidify under a microflow workstation. S . calamistis larvae were obtained from the colony in the Insect Rearing Unit at the IITA, Ibadan, Nigeria. They were maintained on the artificial diet for two generations. Two larvae ( < 12 h old) were introduced into each well of the assay tray containing the treated diet. Each plastic had twenty four wells and represented a treatment. The plastic tray was sealed with a perforated nylon sheet to allow for ventilation. There were three replicates. The treatments were arranged randomly in trays in the laboratory maintained at a temperature of (26±2) °C, (80±5)% relative humidity and 14 h:10 h (light:dark) illumination. Larval survival and weight were recorded at 10 and 20 d after introduction (DAI) from twelve wells per treatment. The fresh weight of the larvae was taken immediately after removal from the diet while the dry weight was taken after drying in the oven for 7 d at 40 °C. The concentration that killed 50% of the larvae (LC 50 ) was calculated at 10 and 20 DAI using probit analysis while data on survival and weight were analyzed using the analysis of variance (ANOVA) (SAS System for Windows, Version 8.2). Means were separated with the Student-Newman-Keuls’ test. RESULTS 1 The percentage survival of S . calamistis larvae reared on the treatments is shown in Table 1 1 . The stem bark was more toxic than the leaf extract against the S . calamistis larvae. The LC 50 of the stem bark extract was 2.8% while that of the leaf extract was 5.6% at 10 DAI. Table 2 2 shows the fresh weight of the larvae reared on the different treatments. There was a significant reduction in the weight of the larvae in a dose dependent manner by both extracts. DAI: Days after introduction; Means followed by the same letters in the same column are not significantly different ( P < 0.05; Student-Newman-Keuls’ test). CL : Confidence limits 3 Concentration (%) 4 Larval survival (%) 2 Stem bark extract 2 Leaf extract 10 DAI 20 DAI 10 DAI 20 DAI 10.0 0.00e 0.00d 16.67d 6.25d 5.0 29.17d 16.67c 64.58c 50.00c 2.5 62.50c 50.00b 83.33b 66.67b 1.0 83.33b 75.00a 95.83ab 79.17ab 0.0 (control) 100.00a 87.50a 100.00a 87.50a LC 50 (%) 2.8 2.1 5.6 3.5 95% CL 2.3~3.4 1.7~2.5 4.7~6.8 2.7~4.4 Means followed by the same letters in the same column are not significantly different ( P < 0.05; Student-Newman-Keuls’ test); DAI: Days after introduction Figures in parenthesis indicate the number of larvae weighed 3 Concentration (%) 4 Mean larval weight (mg) 2 Stem bark extract 2 Leaf extract 10 DAI 20 DAI 10 DAI 20 DAI 10.0 − − 0.00d (8) 0.00e (3) 5.0 1.43d (14) * * 2.40d (8) 1.29cd (31) 10.30d (24) 2.5 2.60c (30) 29.50c (24) 3.73c (40) 30.70c (32) 1.0 5.73b (40) 94.50b (36) 7.23b (46) 87.40b (38) 0.0 (control) 25.46a (48) 214.80a (42) 25.46a (48) 214.80a (42) DISCUSSION 1 The results of our study show that the aqueous extracts of the stem bark and leaf of A . boonei adversely affected survival and growth of S . calamistis larvae. Growth inhibition may result from toxicity or feeding deterrent properties of the extracts (El-Lakwah et al., 1996 1996 ; Akhtar and Isman, 2004 2004 ; Erturk, 2006 2006 ). Since larvae reared on the 10.0% stem bark extract suffered 100% mortality and other doses of this extract caused lower larval survival than the leaf extract, A . boonei stem bark likely contains more potent compounds than the leaves. These substances may be antibiotic or antifeedant in nature (Verkerk and Wright, 1993 1993 ; Kabaru and Gichia, 2001 2001 ; Sadek, 2003 2003 ). The insecticidal activity of A . boonei extract against Maruca vitrata Fabricius was reported by Oigiangbe et al.( 2007 2007 ), while McLaughlin et al. ( 1980 1980 ), Raju et al.( 1990 1990 ), El-Lakwah et al.( 1996 1996 ) and Jeong et al.( 2001 2001 ) observed the bioactivity of other species of the Family Apocyanaceae against different insect species. Some chemical compounds of the indole alkaloid group (alstonine, porphine and astonidine) and triterpenoids have been identified from the bark of A . boonei (Phillipson et al., 1987 1987 ; Anonymous, 1992 1992 ; 2001 2001 ). The insecticidal potential of these compounds has not been investigated or reported in literature. A bioassay-guided fractionation of these extracts will help to identify the compounds responsible for the activity observed in this study. We conclude that the stem bark and leaves of the medicinal plant, A . boonei , contain insecticidal substances that have potential for use as alternative crop protectants against S . calamistis and most likely other pest species. References C Abel , K Busia . An Exploratory Ethnobotanical Study of the Practice of Herbal Medicine by the Akan Peoples of Ghana (Ethnobotanical Study: Herbal Medicine in Ghana) . Alternative Medicine Review , 2005 . 42 . An Exploratory Ethnobotanical Study of the Practice of Herbal Medicine by the Akan Peoples of Ghana (Ethnobotanical Study: Herbal Medicine in Ghana) Y Akhtar , MB Isman . Comparative growth inhibitory and antifeedant effects of plant extracts and pure allelochemicals on four phytophagous insect species . Journal of Applied Entomology , 2004 . 128 ( 1 ): 32 - 38 . DOI: 10.1046/j.1439-0418.2003.00806.x http://doi.org/10.1046/j.1439-0418.2003.00806.x . Comparative growth inhibitory and antifeedant effects of plant extracts and pure allelochemicals on four phytophagous insect species Anonymous . Monograph of Alstonia Bark . Ghana Herbal Pharmacopoeia , 1992 . : Accra Ghana The Advent Press , 10 - 12 . . Monograph of Alstonia Bark Anonymous . Earthnotes Herb Library , 2001 . Ernestinar Parziale CH . Earthnotes Herb Library JL Betti . An ethnobotanical study of medicinal plants among the Baka Pygmies in the dja biosphere reserve, Cameroon . African Study Monographs , 2004 . 25 ( 1 ): 1 - 27 . . An ethnobotanical study of medicinal plants among the Baka Pygmies in the dja biosphere reserve, Cameroon NA Bosque-Perez , ZT Mareck . Distribution and composition of Lepidopterous maize borers in southern Nigeria . Bulletin of Entomological Research , 1990 . 80 363 - 368 . . Distribution and composition of Lepidopterous maize borers in southern Nigeria YA Bruce , S Gounou , A Chabi-Olaye , H Smith , F Schulthess . The effect of neem ( Azadirachta indica A Juss) oil on oviposition, development and reproductive potentials of Sesamia calamistis Hampson (Lepidoptera: Noctuidae) and Eldana saccharina Walker (Lepidoptera: Pyralidae) . Agricultural and Forest Entomology , 2004 . 6 ( 3 ): 223 - 232 . DOI: 10.1111/j.1461-9555.2004.00218.x http://doi.org/10.1111/j.1461-9555.2004.00218.x . The effect of neem (Azadirachta indica A Juss) oil on oviposition, development and reproductive potentials of Sesamia calamistis Hampson (Lepidoptera: Noctuidae) and Eldana saccharina Walker (Lepidoptera: Pyralidae) FA El-Lakwah , MS Hamed , AM Abdel-Latif . Effectiveness of Lantana camera and Nerium oleander extracts alone and in mixtures with two insecticides against Rhizopertha dominica (F.) . Annals of Agricultural Science Moshtohor , 1996 . 34 1879 - 1905 . . Effectiveness of Lantana camera and Nerium oleander extracts alone and in mixtures with two insecticides against Rhizopertha dominica (F.) O Erturk . Antifeedant and toxicity effects of some plant extract on Thaumetopoae solitaria Frey. (Lep.: Thaumetopoeidae) . Turkish Journal of Biology , 2006 . 30 51 - 57 . . Antifeedant and toxicity effects of some plant extract on Thaumetopoae solitaria Frey. (Lep.: Thaumetopoeidae) TR Fasola , A Egunyomi . Nigerian usage of bark in phytomedicine . Ethnobotany Research and Applications , 2005 . 3 73 - 77 . . Nigerian usage of bark in phytomedicine LEN Jackai , JR Raulston . Rearing the legume pod borer, Maruca testulalis Geyer (Lepidoptera: Pyralidae) on artificial diet . Tropical Pest Management , 1988 . 34 ( 2 ): 168 - 172 . . Rearing the legume pod borer, Maruca testulalis Geyer (Lepidoptera: Pyralidae) on artificial diet B James , O Caulibaly , B Gbaguidi . New solutions for cowpea production in Africa . Pesticide News , 2003 . 61 12 - 13 . . New solutions for cowpea production in Africa SE Jeong , Y Lee , JH Hwang , DC Knipple . Effects of the sap of the common oleander Nerium indicum (Apocyanaceae) on male fertility and spermatogenesis in the oriental tobacco budworm Helicoverpa assulta (Lepidoptera: Noctuidae) . The Journal of Experimental Biology , 2001 . 204 3935 - 3942 . 11807111 . Effects of the sap of the common oleander Nerium indicum (Apocyanaceae) on male fertility and spermatogenesis in the oriental tobacco budworm Helicoverpa assulta (Lepidoptera: Noctuidae) JM Kabaru , L Gichia . Insecticidal activity of extracts derived from different parts of the mangrove tree Rhizophora mucronata (Rhizophoraceae) Lam. against three arthropods . African Journal of Science and Technology: Science and Engineering Series , 2001 . 2 ( 2 ): 44 - 49 . . Insecticidal activity of extracts derived from different parts of the mangrove tree Rhizophora mucronata (Rhizophoraceae) Lam. against three arthropods R Kfir , WA Overholt , ZA Khan , A Polaszek . Biology and management of economically important lepidopteran cereal stem borers in Africa . Annual Review of Entomology , 2002 . 47 ( 1 ): 701 - 731 . 11729089 DOI: 10.1146/annurev.ento.47.091201.145254 http://doi.org/10.1146/annurev.ento.47.091201.145254 . Biology and management of economically important lepidopteran cereal stem borers in Africa E Maala , W Kiiya , P Omollo , 等 . Participatory Evaluation of the Effectiveness of Locally Known Plant Extracts and Insecticides in Controlling Maize Stalk Borer . 2000 . (Available from: http://www.kari.org/Legume_Project/Legume2Conf_2000/44.pdf http://www.kari.org/Legume_Project/Legume2Conf_2000/44.pdf ) . Participatory Evaluation of the Effectiveness of Locally Known Plant Extracts and Insecticides in Controlling Maize Stalk Borer JL McLaughlin , B Freedman , S Powel , CRJr Smith . Neriifolin and 2′ acetyl neriifolin insecticidal and cytotoxic agents of Thevitia thevetoides seeds . Journal of Economic Entomology , 1980 . 73 398 - 402 . . Neriifolin and 2′ acetyl neriifolin insecticidal and cytotoxic agents of Thevitia thevetoides seeds ON Oigiangbe , IB Igbinosa , M Tamo . Bioactivity of extracts of Alstonia boonei (Apocynaceae) De Wild Stem Bark against Maruca vitrata (Lepidoptera: Pyralidae) Fabricius . Advances in Science and Technology , 2007 . 1 ( 1 ): 67 - 70 . . Bioactivity of extracts of Alstonia boonei (Apocynaceae) De Wild Stem Bark against Maruca vitrata (Lepidoptera: Pyralidae) Fabricius JD Phillipson , MJ O′Neill , CW Wright , DH Bray , DC Warhurst . Plants as Sources of Antimalarial and Amoebicidal Compounds . Medicinal and Poisonous Plants of the Tropics: Proceedings of Symposium 5~35 of the 14th International Botanical Congress , 1987 . July 24~Aug. 1 1987 Berlin 70 - 78 . . Plants as Sources of Antimalarial and Amoebicidal Compounds M Raju , K Thakur , RG Maruthi . Sterilizing activity of the flower extract of Thevitia neriifolia on the male fifth instar nymph of red cotton bug, Dysdercus similis F. (Heteroptera: Pyrrhocoridae) . Journal of Animal Morphology and Physiology , 1990 . 37 77 - 78 . . Sterilizing activity of the flower extract of Thevitia neriifolia on the male fifth instar nymph of red cotton bug, Dysdercus similis F. (Heteroptera: Pyrrhocoridae) MM Sadek . Antifeedant and toxic activity of Adhatoda vasica leaf extract against Spodoptera littoralis (Lep.: Noctuidae) . Journal of Applied Entomology , 2003 . 127 ( 7 ): 396 - 404 . DOI: 10.1046/j.1439-0418.2003.00775.x http://doi.org/10.1046/j.1439-0418.2003.00775.x . Antifeedant and toxic activity of Adhatoda vasica leaf extract against Spodoptera littoralis (Lep.: Noctuidae) H Terashima . Names, use and attributes of plants and animals among the Ituri forest foragers: a comparative ethnobotanical and ethnozoological study . African Study Monographs , 2003 . 28 ( Suppl. ): 7 - 24 . . Names, use and attributes of plants and animals among the Ituri forest foragers: a comparative ethnobotanical and ethnozoological study RHJ Verkerk , DJ Wright . Biological activity of neem seed kernel extracts and synthetic azadirachtin against larvae of Plutella xyllostella L. . Pesticide Science , 1993 . 37 ( 1 ): 83 - 91 . DOI: 10.1002/ps.2780370113 http://doi.org/10.1002/ps.2780370113 . Biological activity of neem seed kernel extracts and synthetic azadirachtin against larvae of Plutella xyllostella L. We thank Mrs. Aanu Aderanti, International Institute of Tropical Agriculture, Ibadan, Nigeria, for insect rearing. 10.1631/jzus.2007.B0752 Project supported by the Research Grant Committee of the Ambrose Alli University, Ekpoma, Nigeria 2007-06-21 2007-08-13 2022-01-05 Copyright © 2007, Journal of Zhejiang University Science 2007 Journal of Zhejiang University-SCIENCE B (Biomedicine and Biotechnology) 10 08