Performance of Various Pesticides Against Yellow Stem Borer, Scirpophaga incertulas (Walker) of Basmati Rice and Effect on Yield in Northern India

Rice (Oryza sativa Linn.), a vital cereal from the Poaceae family, is essential for global nutrition, especially in Asia, where it provides up to 80% of daily calories for over two billion people. human being throughout the world which can be cultivated in wide range of agro-climate zone of India as well as world (Kumar et al., 2024). In India, rice is grown across 44.5 million hectares, producing about 115.63 million tons (Anonymous, 2019). This versatile crop thrives in tropical, subtropical and temperate zones, growing as far north as 43^oN and south to 39^oS and at elevations reaching 2,500 meters. Rice varieties are broadly categorized as aromatic and non-aromatic. India’s basmati rice, known for its characteristic fragrance, is mainly grown in Haryana, Punjab, Uttarakhand and western Uttar Pradesh. The aroma is particularly notable during harvest, storage and cooking (Kumar and Singh, 2020; Bharti et al., 2018). Besides its culinary appeal, rice holds nutritional value: 100 grams of rice provides 365 kcal, 7.12 grams of protein, 1.3 grams of fibers and small amounts of essential nutrients like thiamine, riboflavin, zinc, calcium, iron and manganese (Anonymous, 2010).
       
Increasing rice productivity is crucial to meet the food needs of a growing population. However, productivity faces challenges from insect pests, diseases and weeds, all of which reduce crop yields (Kumar et al., 2019). Research and management strategies are essential to overcome these challenges and maintain rice as a reliable global food source. The yellow stem borer (Scirpophaga incertulas Walker) is a major pest in rice farming and is responsible for substantial economic losses, affecting rice crops from the seedling stage to harvest. In India, annual rice production losses due to insect pests are estimated at 55.12 million rupees, which accounts round 18.16% of total production losses. Out of this, the yellow stem borer alone is responsible for 20-30% of the damage (Lal, 1996). Among various constraints of rice production, the insect-pests are of prime importance. Disease and insect-pests are estimated to cause yield losses to the tune of 30-40 per cent (Pandey and Choubey, 2012).
       
The use of insecticides is a common and highly effective strategy for managing pests among Indian rice farmers, particularly against destructive pests like the yellow stem borer. Chemical control is a fundamental component of Integrated Pest Management (IPM), a framework that also incorporates biological and cultural control methods to sustainably manage pest populations. However, the indiscriminate use of chemical pesticides has led to several negative outcomes, including a reduction in the biodiversity of natural predators, the emergence of secondary pest outbreaks and environmental contamination, highlighting the importance of careful pesticide selection and application (Singh, 2000).
       
To address these challenges, ongoing research has focused on evaluating the efficacy of both chemical and biological control methods against the yellow stem borer, aiming to identify pest management strategies that are effective while minimizing ecological disruption. By prioritizing options that align with sustainable pest management practices, this research aims to support agricultural productivity while safeguarding human, animal and environmental health.

The field experiment was conducted at the crop research centre (CRC) of S.V.P. University during the Kharif season of 2018. Located at 29^o04' N latitude, 77^o42' E longitude and an altitude of 237 meters above mean sea level (MSL), the experimental site provided suitable conditions for this study on the Pusa Basmati-1 rice variety. The experiment was set up in a randomized block design (RBD) comprising nine treatments and three replications, along with an untreated control. 25 days-old seedlings were transplanted into main plots measuring 5 × 4 m².
       
All treatments were applied twice during peak pest populations: the first application was made 50 days after transplanting, followed by a second application 82 days after transplanting. Applications were carried out using a knapsack sprayer equipped with a hollow cone nozzle. Details of the treatments are summarized in Table 1. Pre-treatment observations were recorded one day before the first application, with data collected from ten randomly selected hills in each plot. Post-treatment observations were recorded on the 3^rd, 7^th and 10^th days after each application, focusing on the number of dead hearts in selected hills, calculated using the formula provided by Chatterjee and Mondal (2014).


               
For grain yield assessment, the weight of both healthy and damaged grains was recorded from each plot and converted to quintals per hectare (q/ha). The cost-benefit ratio of each treatment was also calculated. Statistical analysis was conducted using the analysis of variance (ANOVA) technique for randomized block design, following the methods outlined by Panse and Sukhatme (1978). Data transformations were applied when necessary to meet statistical assumptions. The software “OPSTAT1,” developed by Sheoran (2004), was used for data analysis.

Insect fauna associated with basmati rice
 
Throughout the study, a variety of insect species were identified as pests of rice crops, each exhibiting unique damage characteristics, seasonal abundance patterns and economic significance. A total of thirteen insect species were documented attacking rice at various growth stages in Meerut, Uttar Pradesh, as detailed in Table 2. These species-initiated infestations around 20 days after transplanting, marking a critical period for implementing pest management strategies to minimize impacts on crop yield and quality. This knowledge of the timing and nature of infestations enables farmers to apply timely and effective control measures to safeguard their crops.


 
Efficacy of insecticides on yellow stem borer after first spray
 
Pre-treatment observations
 
Before the application of treatments, pre-treatment observations indicated that the percentage of “dead hearts” in the field ranged from 5.79% to 6.49% across the study plots. Statistical analysis showed that this variation in pre-treatment damage was not significant across treatments, suggesting a relatively uniform pest presence and damage level throughout the field. These baseline observations are summarized in Table 3.


 
Post-treatment observations
 
Three days after spray application
 
Three days after spraying, all treatments showed significantly greater efficacy compared to the untreated control, with chemical pesticides demonstrating the highest reduction in damage from Scirpophaga incertulas. The lowest damage was observed in plots treated with Fipronil 5 SC (5.21%), which was significantly more effective than Imidacloprid 17.8 SC (5.51%) and Cartap hydrochloride 4 G (5.62%). Among the bio-pesticides, Beauveria bassiana and Metarhizium anisopliae were the most effective, reducing damage levels to 6.14% and 6.29%, respectively, while the untreated control exhibited the highest damage at 6.53%. These results are consistent with the findings of Kakde and Patel (2019), who reported that Cartap hydrochloride 4 G was less effective than Fipronil in managing yellow stem borer infestations. This conclusion is further supported by Singh et al., (2017) and Lal (2006).
 
Seven days after spray application
 
After seven days, Fipronil 5 SC continued to provide the best control, achieving the lowest damage level of 3.29%. Imidacloprid 17.8 SC followed with 3.95% damage and Cartap hydrochloride 4 G recorded 4.69%. Other effective treatments included Lambda cyhalothrin 5 EC (5.00%) and Thiamethoxam 25 WG (5.25%). Among bio-pesticides, the order of effectiveness was Beauveria bassiana (5.61%), Metarhizium anisopliae (5.96%) and Verticillium lecanii (6.07%), while the untreated control again showed the highest damage at 6.68%.

Ten days after spray application
 
Ten days after the application, all treatments remained significantly more effective than the untreated control. Chemical pesticides consistently demonstrated strong efficacy, with Cartap hydrochloride 4 G (3.79%), Lambda cyhalothrin 5 EC (3.94%) and Thiamethoxam 25 WG (4.33%) performing particularly well. Among bio-pesticides, Verticillium lecanii (5.94%) was the least effective; however, Beauveria bassiana and Metarhizium anisopliae continued to show promising results, reducing damage to 4.51% and 4.71%, respectively. These findings align with the observations of Sulagitti et al., (2017) and Kumar and Kumar (2017), who identified B. bassiana and M. anisopliae as effective bio-pesticides for controlling yellow stem borer infestations.
 
Efficacy of insecticides on yellow stem borer after second spray
 
Three days after spray application
 
After three days following the second spray, observations confirmed a consistent trend: All treatments significantly outperformed the untreated control. The plots treated with Fipronil 5 SC demonstrated the best performance, exhibiting the lowest percentage of dead hearts at 4.86%, which was statistically comparable to Imidacloprid 17.8 SC at 4.99%. Among the bio-pesticides, Verticillium lecanii was the least effective, showing 5.86% dead hearts.
 
Seven days after spray application
 
On the seventh day of the study, various insecticide treatments were ranked for their effectiveness against the Yellow Stem Borer, S. incertulas. Fipronil 5 SC was the most effective, with a damage level of 3.31%, followed by Imidacloprid 17.8 SC at 3.84%. Cartap Hydrochloride 4 G showed a damage percentage of 4.09%, while Lambda Cyhalothrin 5 EC had 4.30%. Thiamethoxam 25 WG recorded the highest damage at 4.58%. The untreated plot suffered the most damage, underscoring the critical need for pest management. These results highlight Fipronil and Imidacloprid as superior choices for effective pest control.
 
Ten days after spray application
 
By the tenth day post-application, Fipronil 5 SC continued to be the most effective treatment, yielding only 2.03% dead hearts, followed closely by Imidacloprid 17.8 SC at 2.40%, which was statistically comparable to other high-performing treatments. These observations align with the findings of Suri and Makkar (2016), who noted that after seven days, Cartap hydrochloride exhibited minimal damage by the yellow stem borer, comparable to lots treated with Fipronil.
       
In the final observations taken at ten days after application, Fipronil 5 SC remained the best treatment, followed by Imidacloprid 17.8 SC. The subsequent order of effectiveness included Cartap hydrochloride 4 G (3.03%), Lambda cyhalothrin 5 EC (3.47%), Thiamethoxam 25 WG (3.62%), B. bassiana (3.95%), M. anisopliae (4.13%) and V. lecanii (4.42%). The untreated control recorded the highest damage level at 8.14%.
       
In this investigation, Fipronil 5 SC was established as the most effective treatment against damage caused by the yellow stem borer. This finding is consistent with the results of Seni and Naik (2017) and Katel et al., (2023), who also identified Fipronil 5 SC as the most effective, followed by Imidacloprid. Additionally, V. lecanii demonstrated promising results comparable to those of M. anisopliae. Current and previous studies corroborate the effectiveness of these treatments. Furthermore, Fipronil 0.3% GR and Cartap hydrochloride were identified as the next most effective insecticides, aligning with the findings of Panda et al., (2004), Roshan (2006) and Singh et al., (2010).
 
Cost-benefit analysis of treatments
 
The total expenses incurred during the experiment included costs for insecticides, seeds, labor and irrigation charges. The increase in income resulting from the applied treatments was assessed based on the corresponding rice yields. The highest yield was recorded in plots treated with Fipronil 5 SC, achieving 38.35 q/ha, followed closely by Imidacloprid 17.8 SC at 37.26 q/ha. The cost-benefit ratios calculated for each treatment are presented in Table 4.


       
All treated plots yielded significantly higher production, ranging from 32.53 q/ha to 38.35 q/ha, compared to the untreated control, which produced only 26.60 q/ha. The cost-benefit ratio for Imidacloprid 17.8 SC was 1:7.83, followed by Thiamethoxam 25 WG at 1:7.59 and Fipronil 5 SC at 1:6.66. While Fipronil 5 SC provided the highest yield in terms of quintals per hectare, its ranking in cost-effectiveness was lower due to its higher associated costs.

Conversely, Cartap hydrochloride 4 G and Lambda cyhalothrin 5 EC exhibited lower yields, which could be attributed to their effectiveness against other insect pests, such as the brown plant hopper (BPH), Gall Midge and white plant hopper (WPH).
       
From the study, the treatment with Imidacloprid 17.8 SC at 200 ml/ha not only yielded higher grain production but also resulted in greater net profit, corroborating the findings of Sangamithra et al., (2018) and Mishra et al., (2009). The best cost-benefit ratio was recorded for Imidacloprid 17.8 SC at 200 ml/ha (1:7.83), closely followed by Thiamethoxam 25 WG at 100 gm/ha (1:7.59). This finding aligns partially with the results reported by Kumar and Kumar (2017).

During the study conducted in Meerut, Uttar Pradesh, thirteen insect species were identified as pests of rice, including Scirpophaga incertulas and Nilaparvata lugens, with infestations beginning 20 days after transplanting. In terms of insecticide efficacy, pre-treatment observations revealed a dead heart rate ranging from 5.79% to 6.49%, indicating no significant damage across treatments. Post-treatment results demonstrated that Fipronil 5 SC was the most effective, reducing damage to 5.21%, outperforming Imidacloprid 17.8 SC (5.51%) and Cartap hydrochloride 4 G (5.62%). Among bio-pesticides, Beauveria bassiana and Metarhizium anisopliae achieved damage levels of 6.14% and 6.29%, respectively. After the second spray, three days post-application, Fipronil 5 SC again exhibited the lowest damage at 4.86%. Seven days later, it remained the top performer with 3.31% dead hearts, followed by Imidacloprid 17.8 SC (3.84%). By day ten, Fipronil continued to show impressive results with just 2.03% dead hearts, reinforcing its superiority. In terms of yield, the highest production was recorded at 38.35 q/ha with Fipronil 5 SC, yielding a cost-benefit ratio of 1:6.66, while Imidacloprid 17.8 SC yielded 37.26 q/ha with the best cost-benefit ratio of 1:7.83. Overall, all treated plots significantly outperformed the untreated control (26.60 q/ha), underscoring the effectiveness of insecticides like Fipronil and Imidacloprid in enhancing rice productivity.

On behalf of all authors, I sincerely thank the Department of Entomology, S.V.P. University of Agriculture and Technology, Meerut and the Indian Council of Agricultural Research (I.C.A.R.), New Delhi, for providing the necessary facilities, guidance and support that enabled the timely completion of this research.
 
Declaration
 
The authors declare that this research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. All findings and conclusions presented in this paper represent the original work of the authors, with no external influences affecting the study design, data interpretation, or reporting of the results.
 
Funding
 
All findings and interpretations are solely those of the authors.
 
Authorship
• Sushant Kumar: Writing-review and editing.
• Hem Singh: Supervision, Conceptualization and Methodology.
• D.V. Singh: Supervision and analysis.
• Shankar Dayal Bharti:  Data curation.
• Chandan Kumar Panigrahi: Revision and Correction.
• Ankit Rai: Preparation of final draft.

The authors declare that there are no conflicts of interest regarding the publication of this paper.