scholarly journals Insecticidal Activity of Ethanolic Leaf Extracts against the Maize Weevil, sitophilus zeamais Motsch (Coleoptera: Curculionidae)

2018 ◽  
Vol 1 (1) ◽  
pp. 1-7
Author(s):  
Suleiman M ◽  
Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 532
Author(s):  
William R. Patiño-Bayona ◽  
Leidy J. Nagles Galeano ◽  
Jenifer J. Bustos Cortes ◽  
Wilman A. Delgado Ávila ◽  
Eddy Herrera Daza ◽  
...  

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.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
A.G.W.U. Perera ◽  
M.M.S.C. Karunaratne ◽  
S.D.M. Chinthaka

Neem (Azadirachta indica A. juss), is known to possess a wide range of pharmacological properties and is thus commercially exploitable. Apart from its medicinal potential, a considerable progress has been achieved regarding biological potential and chemical composition of the leaves which is an ever-increasing interest to the scientific community. During this study, biological phenomena and secondary metabolite composition of A. indica leaves were examined in the management of Sitophilus zeamais on stored maize. Insecticidal and repellent potential of A. indica leaf powders were evaluated in both contact and fumigant forms. Phytochemical screening of 11 phyto constituents was performed following the standard procedures for n-hexane, dichloromethane, ethyl acetate, methanol and aqueous leaf extracts. Volatile profile of A. indica leaves was characterized by employing headspace-solid-phase micro extraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS). Over 60% weevil repellency was recorded at doses above 23.33%, whereas 100% and 67% contact and fumigation mortalities were observed respectively, 9 days after treatment at the dose of 33.33% and the respected LD50 values were 1.56 g and 4.48 g. Thirty two volatile compounds were identified in three distinct chemical classes (Monoterpenoid, sesquiterpenoid and purine nucleosides). γ-Elemene (24.06%), 3,7 (11)-eudesmadiene (6.83%), caryophyllene (6.40%), and 10s,11s-himachala-3(12),4-diene (6.36%) were the major constituents of neem leaf volatiles, followed by other compounds present in less than 4% which might be responsible for varied biological activities observed. Thus the odour impact of the bioassayguided study clearly implies that A. indica leaves can be harnessed against S. zeamais infestations.Keywords: Azadirachta indica, Sitophilus zeamais, headspace-solid-phase micro-extraction, insecticidal activity, repellency


2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Alfia Wulansari ◽  
Nur Rochman ◽  
Setyono Setyono

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


2020 ◽  
Vol 39 (1) ◽  
pp. 1
Author(s):  
Ayyub Arrahman ◽  
Muhammad Sudjak Saenong

<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>


2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
K. Bhusal ◽  
D. Khanal

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.


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