An experiment to manage rice weevil (Sitophilus oryzae L. Coleoptera: Curculionidae) in wheat (Triticum aestivum L. Gramineae) was carried out at Institute of Agriculture and Animal Science (IAAS), Paklihawa Campus, Rupandehi, Nepal. The experiment was conducted under completely randomized design (CRD) with seven treatments viz. neem leaf dust (Azadirachta indica A. Juss) 15g/kg, tobacco leaf dust (Nicotiana tabacum L.) 10g/kg, ginger rhizome powder (Zingiber officinale Roscoe) 20g/kg, garlic cloves powder (Allium sativum L.) 20g/kg, Sichuan pepper seed powder (Zanthoxylum armatum Roxb.) 10g/kg, sweet flag rhizome dust (Acorus calamus L.) 5g/kg, and control with three replication. Result revealed that the highest mortality of weevils was observed in the wheat seed treated with A. calamus (98.33), followed by N. tabacum (85.67), A. sativum (73.34), A. indica (70.67), Z. armatum (70.34), and Z. officinale (58.34). Similarly, the lowest percent weight loss (3.32) and damage of seed (4.0) were observed in wheat treated with A. calamus. Moreover, the highest germination (89) was observed in seeds treated with A. calamus rhizome powder when tested at 90 days after treatment application. Based on weevil mortality and the germination test, it is found that sweet flag rhizome powder is the best treatment against rice weevil followed by tobacco leaf dust and garlic clove powder. Therefore, these botanicals could be one of the effective alternatives for the management of weevil especially to the farmers who do not use chemical insecticides in the rural areas of Nepal.

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.

The fall armyworm (FAW), Spodoptera frugiperda, is a highly destructive pest recently reported in various Asian countries and originated in the subtropical regions of America. It was first recorded in Nepal on May 9, 2019. This invasive species poses a significant threat to maize production because it can undergo multiple generations, migrate, and feed on a wide range of host plants. A laboratory study was conducted with 3 categories of pesticides: conventional, newer, and bio‐rational. The study focused on evaluating the efficacy of these pesticides on the third‐instar larvae of S. frugiperda. The treatments included (1) newer chemical pesticides: spinosad 45% suspension concentrate (SC) (Tracer 1 ml/3 L of water), spinetoram 11.7% SC (Delegate 0.5 ml/L of water), chlorantraniliprole 18.5% SC (Allcora 1 ml/2.5 L of water), emamectin benzoate 5.7% water dispersible granules (WDG) (top killer 1 g/2.5 L), (2) conventional pesticide: chlorpyrifos 50% EC (Predator 2 ml/L), and (3) bio‐rational pesticides: Bacillus thuringiensis var kurstaki 0.5% wettable powder (WP) (Maharashtra 2gm/L), Metarhizium anisopliae 1.0% WP (Kalichakra 5 ml/L), Beauveria bassiana 2% AS (DamanL 5 ml/L), Azadirachta indica 4.5% (Neemix 5 ml/L), Syzygium aromaticum 100% v/v (Kanti herbal Clove oil 3 ml/L), and spinosad 45% SC (Tracer 0.3 ml/L). Fresh maize leaves were treated using the leaf dip method and then fed to 3rd instar larvae of FAW. The results revealed that spinetoram and spinosad caused 100% larval mortality within the first 24 hours after treatment. Similarly, spinosad (99.99%) and clove oil (76.64%) were the most effective bio‐rational pesticides followed by B. bassiana and B. thuringiensis. The newer and bio‐rational pesticides that showed high efficacy could be suggested for further study in farmers’ fields. They could be recommended for testing as a component of integrated pest management for effective management of FAW in Nepal.

The field experiment was conducted from March to June of 2017 in field conditions at the Institute of Agriculture and Animal Science (IAAS), Paklihawa Campus, Rupandehi, Nepal to evaluate the efficacy of botanicals, microbial, and chemical insecticide against Leucinodes orbonalis Guenee. We assessed seven treatments including control in randomized complete block design with four replications and two sprays. The treatments evaluated for the management of L. orbonalis were i) Jholmal, 250 ml/l of water ii) Beauveria bassiana (Daman), 4 g/l water iii) Abamectin 5 % (Biotrine), 0.5 ml/l of water iv) Bacillus thuringiensis var. kurstaki (Mahastra), 4 g/l of water v) Emamectin benzoate (Cobra), 0.5 g/l of water vi) Azadirachtin 1500 ppm (Neem Kavach), 5 ml/l of water vii) Control (pure water application). All the treatments applied were found to be superior to the control. The results revealed that the lowest percentage of infested fruit i.e. 57.97% and 34.52% were found at 14 days after the first and second spray of Emamectin benzoate treatment respectively, as well as it was found to be significant over control in both sprays. The marketable yield of plot treated with Emamectin benzoate in eggplant was found to be the highest i.e.7.19 t/ha and 7.13 t/ha which was followed by Neem Kavach with the yield of 6.69 t/ha and 7.06 t/ha and that of control plots was 2.98 t/ha and 2.56 t/ha after first and second spray respectively. Further, our study concluded both marketable yield and Benefit-Cost (BC) ratio of brinjal fruit were the highest under the treatment of Emamectin benzoate followed by Jholmal and Neem Kavach. From this experiment, we concluded that Emamectin benzoate was the most effective treatment for the management of L. orbonalis while Jholmal and Neem Kavach proved to be the best alternative.