Efficacy of bio-rational insecticides against major rice pests under field conditions in South Sulawesi, Indonesia

Field evaluation of biorational insecticides for managing major rice pests and conserving natural enemies in South Sulawesi

Efficacy of Newer Insecticides against Sucking Pests of Black Gram (Vigna Mungo L.)

Afield experiment was carried out to evaluate the efficacy of some newer insecticide molecules against major sucking pests on black gram and their impact on associated natural enemies and incremental benefit. Out of twelve treatments tested, ten were from novel groups including spinetoram, flonicamid, diafenthiuron, pyriproxyfen, spiromesifen, dinotefuran, clothianidin, cyantraniliprole, fipronil and pymetrozine. Whitefly, leaf hopper, aphid and flower thrips were recorded as major sucking pests. Diafenthiuron emerged as the most effective insecticide against whitefly (97.7% reduction), leaf hopper (91.2%) and aphid (96.2%) and yielded the highest (1208.33 kg ha-1). Fipronil significantly controlled flower thrips (86.2%) as compared to other treatments. All the tested treatments did not show any detrimental impact on associated natural enemies. Clothianidin treated plots resulted in highest incremental cost benefit ratio (1:25.8) followed by flonicamid (1:18.7), dinotefuran (1:16.7) and diafenthiuron (1:15.6), highlighting their economic feasibility in integrated management program.

Comparative Efficacy of Biopesticides and Chemical Insecticides against Myzus persicae (Sulzer) and Bemisia tabaci (Gennadius) in Potato Crop under Western Uttar Pradesh Conditions

A field experiment was conducted during the Rabi season of 2021–22 at the Crop Research Centre, Chirori, Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, Uttar Pradesh, to compare the efficacy of selected biopesticides and chemical insecticides against Myzus persicae and Bemisia tabaci in potato. Seven treatments, namely neem oil, Beauveria bassiana, Difenthiuron 50 WP, Thiamethoxam 25 WG, Pymetrozine 50 WG, Imidacloprid 17.8 SL, and an untreated control, were evaluated in a randomised block design with three replications. Two foliar applications were made at 30 and 45 days after planting, and pest populations were recorded before spraying and at 5 and 10 days after each application. Based on the overall mean across both sprays, Pymetrozine 50 WG at 300 g/ha recorded the lowest aphid population, with 1.35 aphids per three leaves per plant. Difenthiuron 50 WP at 500 g/ha recorded the lowest whitefly population, with 0.99 whiteflies per three leaves per plant. Thiamethoxam 25 WG and Imidacloprid 17.8 SL were the next most effective treatments against both pests, whereas Beauveria bassiana and neem oil provided moderate suppression. All evaluated treatments significantly reduced pest populations compared with the untreated control. The findings indicate that Pymetrozine and Difenthiuron may be considered effective components of integrated management programmes for aphids and whiteflies, respectively, in potato under Western Uttar Pradesh conditions.

Bioefficacy of botanical and chemical insecticides against brown planthopper, Nilaparvata lugens (Stal) (Hemiptera: Delphacidae), in paddy crop

The present study was conducted to evaluate the bioefficacy of botanical and chemical insecticides against brown planthopper, Nilaparvata lugens (Stal), in paddy. The experiment was conducted using the following treatments Azadirachtin 5 % (60, 70 and 80 mL), BrahamAstra (7.5, 10.0 and 12.5 L), homemade neem (2.0, 3.0 and 4.0 L), Oshean 20 SG (80 g) and an untreated control. Two sprays were applied, the first at the initial appearance of the pest and the second at the economic threshold level (ETL). Oshean 20 SG (80 g) recorded the lowest brown planthopper population and the maximum percentage reduction over the control after both sprays. Among different treatments, Azadirachtin (5 %) at 80 mL dose recorded lowest brown planthopper population. All botanical insecticides were safe for the spider population. Grain yield was recorded higher in Oshean 20 SG treatment followed by the botanical insecticides. Azadirachtin 80 mL proved to be the most effective and environment friendly alternative for brown planthopper management in paddy.

Response of new insecticides against major insect pests of tomato in West Shoa, Ethiopia

The tomato (Lycopersicon esculentum Mill.) is cultivated in different parts of Ethiopia in the field as well as in the glasshouse for consumption and processing. Helicoverpa armigera, Tuta absoluta and Liriomyza spp. are damaging insect pests, specifically the tomato crop. In the present study, the laboratory and glasshouse studies were carried out at the Ambo University laboratory, whereas the field experiments were carried out in 2 districts of West Shoa of Ethiopia. The experiments were conducted to evaluate the efficacy of new insecticides against T. absoluta, H. armigera and Liriomyza spp. on tomato crops. The laboratory results showed that the tested insecticides were significantly (p £ 0.05) different after 72 hr of treatment application. The mean mortality was obtained by Benezer Plus 38.5 % E.C and Delta 2.5 % E.C at maximum rate which proved the most effective and gave ((84.03 ± 1.57; 84.42 ± 1.46 %), (85.03 ± 1.48; 84.02 ± 1.59 %) and (78.27 ± 1.27; 68.03 ± 1.18 %)) against T. absoluta, H. armigera and Liriomyza spp. respectively. The glasshouse and field results also revealed that there was a significant reduction in the larval population of T. absoluta, H. armigera and Liriomyza spp. in protected plots as compared to unprotected plots after spraying of insecticides, which ultimately increased the % of marketable yield in sprayed plots. Therefore, the combination of Phenthoate and Emamectin benzoate (Benezer plus 38.5 % E.C) and Deltamethrin (Delta 2.5 % E.C) was found more effective at the maximum rate against T. absoluta, H. armigera and Liriomyza spp. on tomato crops in the glasshouse as well as under open farmers' field conditions. Therefore, these findings could guide farmers and policymakers in selecting cost-effective insecticide regimes.  

Comparative Field Evaluation of Selected Botanical Biopesticides against Fall Armyworm, Spodoptera frugiperda, in Maize (Zea mays L.) Agroecosystems

Fall armyworm, Spodoptera frugiperda, is a major insect pest of maize that causes substantial crop damage through larval feeding on leaves and whorls. The present field study was conducted at Mallikudurla Village, Velair Mandal, Hanumakonda District, Telangana State, India, to evaluate and compare the field efficacy of selected botanical biopesticides against Spodoptera frugiperda in maize (Zea mays L.). The experiment was conducted in a Randomised Block Design with six treatments and four replications. Five botanical treatments comprising neem (Azadirachta indica) extract, Pongamia pinnata seed extract, garlic (Allium sativum) extract, chilli (Capsicum spp.) extract, and a combined botanical formulation were compared with an untreated control. The treatments were evaluated based on fall armyworm larval population, leaf and whorl damage, maize growth, yield attributes, and grain yield. All botanical treatments reduced larval population and crop damage compared with the untreated control. Among the evaluated treatments, the combined botanical formulation showed the highest overall performance, recording the lowest larval population and crop damage and the highest grain yield. Reduced fall armyworm infestation and damage were associated with improved maize growth, yield attributes, and grain yield. The combined botanical treatment recorded the highest grain yield, whereas the untreated control recorded the lowest yield. The results indicate that selected botanical biopesticides have the potential to reduce fall armyworm infestation and crop damage in maize under field conditions. Their incorporation into integrated pest management programmes may help reduce dependence on synthetic insecticides and support sustainable maize production. Further field evaluation is recommended to optimise botanical formulations, application rates, timing, persistence, and cost-effectiveness under different agroecological conditions.