Phytochemical Screening of Selected Botanicals and their Effectiveness Against Maize Weevil (Sitophilus Zeamais Motsch.) at Paklihawa, Rupandehi, Nepal

Laboratory experiment was done to perform the phytochemical screening of six locally available botanicals (Azadirachta indica Juss, Artemisia dubia Wall, Lantana camara L, Parthenium hysterophorus L, Justicia adhatoda Linn. and Moringa oleifera L.) and their effectiveness to control the maize weevil (Sitophilus zeamais Motsch.) at Agriecology lab of Institute of Agriculture and Animal Science, Paklihawa Campus, Rupandehi, Nepal. Seven treatments (leaf extract of A. indica, A. dubia, L. camara, P. hysterophorus. J. adhatoda and M. oleifera and distilled water as control) applied at 3 different doses (0.5, 1 & 2g/50g seeds) were arranged in CRD design with 3 replications. Result of mortality test of maize weevil revealed that, at highest concentration of L. camara powder (T17- 2g/50 gm seeds) mortality of maize weevil was observed up to 85% at 45 DAT. Whereas number of damaged grain was lowest in T17 (L. camara powder- 2g/50 gm seeds). The effectiveness of botanicals was found to increase with increasing the concentration. Besides that, Justicia adhatoda (2g/50g seeds) and Artemisia dubia (1g/50g seeds) were also found as good candidates to use for the control of Sitophilus zeamais. Qualitative tests done for the presence of various phytochemicals showed that Azadirachta indica Juss and Artemisia dubia Wall. were found to contain most of the tested metabolites among all botanicals. Most of those phytochemicals were extracted by the aqueous solution rather than other 3 menstrums used (acetone, methanol and petroleum ether). Similarly, quantitative test revealed that percentage of alkaloid was found 18.01%, 17.78%, 17.75%, 11.58%, 8.20%, 6.78% and flavonoid15.32%, 13.63%, 12.86%, 11.36%, 7. 51% 2.85% respectively in L. camara L. P. hysterophorus L., J. adhatoda Linn., M. oleifera L., A. indica Juss. and A. dubia Wall. Leaf extract of L. camera found to contain highest botanicals extract reach in alkaloid and flavonoid mayhave insecticidal property and could be use as grain protectant percentage of alkaloid (18.01%) as well as flavonoid (15.32%) So, it was concluded that the locally available against the maize weevil at storage condition in cost effective and eco-friendly manner; however, application at proper dose is necessary to maintain the efficacy at higher level.

Activités antioxydante et insecticide d’huiles essentielles de Mentha arvensis L. du Sénégal

Ce travail s'inscrit dans le contexte global de valorisation de la biodiversité des plantes aromatiques du Sénégal. L’objectif de l’étude était de déterminer la composition chimique d’huiles essentielles (HE) de Mentha arvensis L. et d’évaluer leurs activités antioxydante et insecticide. A cet effet, des feuilles de M. arvensis ont été récoltées dans la région de Dakar (Sénégal) et séchées à l'ombre puis leurs HE extraites par entrainement à la vapeur d'eau. Les HE obtenues ont été analysées par chromatographie en phase gazeuse (CPG) couplée à un détecteur à ionisation de flamme (FID) et un spectromètre de masse (MS). L’activité antioxydante des HE a été évaluée par la méthode d’inhibition du radical 2,2-diphényl-1-picrylhydrazyl (DPPH) tandis que l’activité insecticide a été testée par fumigation contre Sitophilus zeamais (Motsch.). Les résultats ont montré que les HE contiennent principalement du menthol (68,4%), de l’acétate de menthyle (16,9%) et de la menthone (5,0%). Leur activité antioxydante augmente avec la concentration, soient 38%, 57% et 73% d’inhibition respectivement pour 10, 25 et 50 mg/ml ; la CI50 est de 19,5 mg/ml. Les huiles présentent aussi une activité insecticide. Cette dernière bien qu’étant faible après 24 heures, augmente fortement au bout de 48 heures avec une mortalité maximale de 92%. Cette mortalité atteint des maximums de 98% pour 5 et 25 μl et 100% pour 50 et 75 μl après 72 heures. English title: Antioxidant and insecticidal activities of essential oils of Mentha arvensis L. from Senegal This work is part of the global context of valorization of the biodiversity of aromatic plants from Senegal. The aim of the study is to determine the chemical composition of essential oils (EOs) of Mentha arvensis L. and to evaluate their antioxidant and insecticidal activities. For this purpose, leaves of M. arvensis were harvested in Dakar region, Senegal and dried in the shade. EOs were extracted by steam distillation from dried leaves and analyzed by gas chromatography (GC) coupled to a flame ionization detector (FID) and a mass spectrometer (MS). The antioxidant activity of EOs was assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method while the insecticidal activity was tested by fumigation against Sitophilus zeamais (Motsch.). The results revealed that EOs were dominated by menthol (68.4%), menthyl acetate (16.9%) and menthone (5.0%). The antioxidant activity assay showed that the inhibition increased with the concentration: 38%, 57% and 73% for 10, 25 and 50 mg/ml, respectively; the IC50 was of 19.5 mg/ml. The oils were also effective as insecticide. Mortalities were low after 24 hours and increased strongly after 48 hours with a maximum of 92%. They reached a maximum of 98% for 5 and 25 μl and 100% for 50 and 75 μl after 72 hours.

Effects of Essential Oils from 24 Plant Species on Sitophilus zeamais Motsch (Coleoptera, Curculionidae)

Chemical control of the maize weevil (Sitophilus zeamais) has been ineffective and presents serious collateral damage. Among plant-derived insecticides, essential oils (EOs) are suitable candidates to control this stored products pest. In this work, the insecticidal activities of 45 natural EOs against S. zeamais adults were screened, and the most promising ones (24 EOs) were characterized by GC–MS. The repellent and toxic effects (contact and fumigant) of these 24 EOs were determined, and by a cluster analysis they were classified into two groups considering its fumigant activity and contact toxicity. For the EOs with the highest fumigant potential (14 oils) and their main active constituents (17 compounds), lethal concentrations were determined. The most active EOs were those obtained from L. stoechas and L. alba, with LC50 values of 303.4 and 254.1 µL/L air and characterized by a high content of monoterpenes. Regarding the major compounds, the oxygenated monoterpenes R-(+)-pulegone (LC50 = 0.580 mg/L air), S-(-)-pulegone (LC50 = 0.971 mg/L air) and R-(-)-carvone (LC50 = 1.423 mg/L air) were the most active, as few variations in their concentrations significantly increased insect mortality.

PROTECTANT EFFICACY OF DENNETIA TRIPETALA BAK. (F) (ANNONACEAE) EXTRACTS AND DELTAMETHRIN AGAINST SITOPHILUS ZEAMAIS MOTSCH (COLEOPTERA: CURCULIONIDAE) IN STORED MAIZE

The use of plant products has shown great potentials as alternatives to synthetic insecticides. The present studies investigated the efficacy of Dennetia tripetala and Deltamethrin as grain protectants against adult Sitophilus zeamais in stored maize. Acetone extracts of D. tripetala and Deltamthrin 12.5EC were evaluated in the laboratory based on insect mortality, progeny production and grain damage. Five concentration levels of each toxicant were prepared including 20mls, 15mls, 10mls, 5mls and 1ml for D. tripetala and 1ml, 0.5ml, 0.25ml, 0.1ml and 0.01ml for Deltamethrin. Controls with no toxicants were included. The design of the experiment was a CRD and each repeated 4 times. Twenty grams of insect-free maize were measured into each replicate vial and infested with ten, 1-5-days old adult insects. Mortality was recorded at 12, 24, 48- and 72-hours post-treatment. After 35 days, progeny production and number of damaged grains were recorded. Data obtained were statistically analyzed using SPSS version 13. The results indicated that Deltamethrin was more toxic than Dennetia tripetala, however, at 10mls-20mls, D. tripetala showed moderate toxicity against S. zeamais. Comparative mortalities of the two toxicants indicated that Deltamethrin was significantly (P < 0.05) more toxic than D. tripetala at all levels. The studies however, revealed that the application of D. tripetala in controlling S. zeamais could be effective at higher concentrations. Therefore, it was suggested that D. tripetala should be applied at higher concentrations for effective control of maize weevil.

SPICES PLANT AS BIOINSECTICIDES FOR CONTROLLING MAIZE WEEVIL SITOPHILUS ZEAMAIS (MOSTCH) Pemanfaatan Tanaman Rempah sebagai Pestisida Nabati untuk Penanggulangan Hama Kumbang Bubuk Jagung Sitophilus zeamais (Mostch)

<p>Indonesia has numerous and varied natural resources of spices plant which grow at almost all theregions. These plants can grow and adapt to the slightly diverse agroecological conditions and agroecosystems, from dry to wet. In general, the utilization of these plants by the community is still limited as ingredients and spices for culinary and flavoring instead of the potential of bioactive compounds contained therein. These resourcesare very useful and effective utilized asbioinsecticides to eradicate plant pests and diseases, as well as medicine for human. This paper discussed the benefits and efficacy of several spiceplants, namely lemongrass, shallots, garlic, sweet and chili peppers, clove, sand ginger (kencur), and pepper as herbicides at various levels of dosage and treatments. This manuscript also discussed the constraints and development strategies, and aimed to provide information on the science and technology in controlling the Sitophilus zeamais (Motsch) pests in corn kernels during the storage period. It is expected that this paper would be useful for the policy makers, academicians, researchers and practitioners who have the competence to deal with beetle pest problems.</p><p>Keywords: Spices, bioinsecticides, Sitophilus zeamais (Motsch), controlling</p><p> </p><p><strong>Abstrak</strong></p><p>Tanaman rempah yang tumbuh di hampir seluruh wilayah Indonesia sangat beragam. Tanaman ini beradaptasi pada berbagai agroekologi dan agroekosistem, mulai dari wilayah beriklim kering sampai beriklim basah. Pemanfaatan tanaman ini oleh masyarakat umumnya masih terbatas sebagai bahan rempah dan bumbu kuliner, penyedap masakan dan cita rasa, padahal senyawa bioaktif yang terkandung di dalamnya potensial sebagai pestisida nabati untuk membasmi hama penyakit tanaman dan bahan obat kesehatan manusia. Tulisan ini membahas manfaat dan kemanjuran dari beberapa tanaman rempah, yakni tanaman sereh, bawang merah, bawang putih, lombok merah, cengkeh, kencur, dan lada sebagai pestsisida nabati dalam berbagai dosis dan ragam perlakuan. Kendala dan strategi pengembangan pestisida nabati bagi penggulangan hama kumbang bubuk perlu mendapat perhatian yang tidak saja untuk kepentingan masyarakat luas, namun diperlukan sebagai informasi ilmu dan teknologi penanganan hama secara terpadu.</p><p>Kata kunci: tanaman rempah, bioinsektisida, hama kumbang bubuk, pengendalian</p>

Potentials of Grinting Grass (Cynodon dactylon l.) For Biopesticides On Sitophylus Zeamais Motsch Mortality

Corn is one of the cereals that has strategic and economic value and has the opportunity to be developed. The attack of the Sitophilus Zeamais Motsch species becomes one of the obstacles in the process of storing corn. This study aims to develop the potential of plant biopesticides from grinting grass to control the warehouse pests of Sitophilus Zeamais Motsch. This research is a laboratory based experimental study. The independent variables in this study were the gram weight of grinting grass extract and the number of Sitophilus Zeamais Motsch pests. The dependent variable in this study was the mortality of Sitophilus Zeamais Motsch. Grinting grass extract is obtained using maceration method. Qualitative and quantitative tests were carried out to test the active compound content of grinting grass. Vegetable biopesticide toxicity tests were carried out using a completely randomized design. The results showed that variations in the weight of grinting grass affect the content of chemical compounds present in the grass. Based on UV-Vis and FTIR spectra, the content of polyphenols, alkaloids, flavonoids, terpenoids, steroids, and saponins contains 20 gr / 100 mL, there are flavonoids as much, 2.38 mg / mL, saponins as 2.04 mg / mL, alkaloids as much as 1.79 mg / mL, polyphenols 3.15 mg / mL, steroids as much as 2.24 mg / mL and terpenoids as much as 3.15 mg / mL. Based on qualitative tests the active compound is evidenced by changes in color and deposition. While based on pest mortality tests, it was found that almost 50 percent of grinting grass extract can kill corn pests within a period of 7 days of observation with an extract concentration of 800 ppm. Key words: Biopesticides, Grinting Grass, Uv-Vis

The Insecticide Toxicity and Repelling Ability of Jeruk Purut (Citrus hystrix D.C) Leaf Extract on Maize Weevil (Sitophilus zeamais Motsch)

Sitophilus zeamais Motsch. is a primary storage insect pest damaging maize grains. Control of S. zeamais can be done by applying biopesticide. This study was aimed at assessing the ability of Jeruk Purut leaf extract, as biopesticide, to kill and repel Sitophilus zeamais Motsch. The study was conducted at Entomology Laboratory, Seameo Biotrop in March to August 2018. A completely randomized design with three replicates in each rate of Jeruk Purut leaf extract was used. In preliminary pesticide toxicity experiment, five rates of Jeruk Purut leaf extract, namely 0%, 2%, 4%, 6%, and 8% were applied. In preliminary repelling ability experiment, five rates of Jeruk Purut leaf extract, namely 1%, 2%, 4%, 6%, and 8% were applied. In the main pesticide toxicity and repelling ability trial, five rates of Jeruk Purut leaf extract, namely 3%, 6%, 9%, 12%, and 15% were applied. Results showed that in 24 hour after treating (HAT) no significant effects were found. Significant effects of Jeruk Purut leaf extract as insecticide on S. zeamais were found in 48 and 72 HAT. The highest mortality rate (82.2%) of S. zeamais was found in 15% rate of Jeruk Purut leaf extract in 72 HAT. The application of Jeruk Purut leaf extract was not found to give significant effects on repelling S. zeamais in 24, 48, and 72 HAT as indicated in their sharply fluctuating repellent values. The highest repelling ability (95%) was found in the application of 9% Jeruk Purut leaf extract in 24 HAT. It was concluded that Jeruk Purut leaf extract was more potential as insecticide repellent for Sitophilus zeamais Motsch. Key words: biopesticide, repellent, insecticide, maize, primary storage insect pest

Role of Maize Weevil, Sitophilus zeamais Motsch. on Spread of Aspergillus section flavi in Different Nepalese Maize Varieties

Experiments were conducted to find out the role of maize weevil, Sitophilus zeamais Motsch. on spread of green fungus, Aspergillus section flavi, in different varieties of stored maize in laboratory in 2016. Lab experiment was conducted to find the role of weevil on spread of A. flavus on five main varieties of maize grown at Nepal in split plot design, namely, Arun-2, Arun-4, Manakamana-1, Manakamana-3, and Rampur composite with three replications at NAST, Khumaltar, from August to September 2016. One hundred grams of each maize variety was exposed to weevil along with fungus and with fungus only to see the spread of the fungus under presence and absence of weevil. Among the tested five maize varieties, the lowest infestation was observed on Rampur Composite (14.99%) while it was the highest on Manakamana-3 (87.70%). The highest mean infestation (75.58%) was found under weevil released condition while it was lower (62.16%) under nonreleased condition. In presence of weevil, the infestation of the fungus increased and in their absence the infestation was low which signifies the role of weevil in fungal spread. All indices indicate that Rampur composite is the best variety among the five tested varieties in terms of storage under the presence of fungus and weevils. This study also indicates ample scope for further study on different varieties of maize under several storage conditions.

Viabilitas Benih Jagung Lokal yang diberi Tepung Daun Tembelekan (Lantana camara Linn) dalam Pencegahan Serangan Sitophilus zeamais Motsch (Coleoptera:Curculionidae) Selama Penyimpanan

Sitophilus zeamais Motsch (Coleoptera:Curculionidae) sering menyerang benih jagung selama periode penyimpanan sehingga dapat menurunkan viabilitas benih. Tembelekan (Lantana camara linn) memproduksi senyawa metabolit sekunder yang dapat berperan melindungi jagung dari gangguan Sitophilus zeamais. Tujuan penelitian ini adalah mencegah serangan hama Sitophilus zeamais dengan tepung daun tembelekan untuk meningkatkan viabilitas benih jagung selama penyimpanan. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) pola faktorial. Faktor pertama adalah takaran tepung tembelekan, yang terdiri dari empat level yakni T0: tanpa tepung, T1: 10% w/w, T2: 15% w/w, T3: 20% w/w. Faktor kedua adalah lama kontak penyimpanan yang terdiri dari 3 level yakni M0: 1 minggu, M1: 2 minggu, dan M2: 3 minggu. Hasil penelitian menunjukkan bahwa interkasi perlakuan tepung daun tembelekan dan periode simpan mampu mempertahankan viabilitas dan vigor benih jagung lokal pada peubah potensi tumbuh maksimum 97,33%, kecepatan tumbuh 19,06%/etmal, indeks vigor 71% dan berat kering kecambah normal 5,4 gram.