Ramesh Koirala, Sita Adhikari and Dipendra Shrestha

The intensification of global agriculture has heavily relied on synthetic pesticides, leading to widespread ecological concerns, health risks, and the rapid emergence of resistant pest populations. This research explores the potential of herbal biopesticides as sustainable alternatives, focusing on phytochemical pathways and their role in resistance management. Plant extracts from Azadirachta indica (neem), Ocimum sanctum (tulsi), Eucalyptus globulus, and Lantana camara were evaluated for their efficacy against resistant populations of Helicoverpa armigera and Spodoptera litura. Phytochemical analysis revealed that neem and tulsi were particularly rich in terpenoids, flavonoids, and phenolics, correlating with their superior insecticidal activity. Bioassays demonstrated dose-dependent mortality, significant larval weight reduction, and suppression of pupation and adult emergence, with neem 2.0% outperforming the synthetic pesticide standard in several parameters. Resistance monitoring across generations indicated a sharp increase in resistance ratios under synthetic treatments, whereas neem extracts maintained low resistance development, underscoring the evolutionary advantage of phytochemical diversity. Statistical analyses confirmed highly significant differences across treatments, validating the effectiveness of herbal biopesticides. The results highlight that integrating such botanicals into Integrated Pest Management (IPM) programs can reduce reliance on chemical pesticides, delay resistance onset, and enhance crop protection sustainably. Practical recommendations include scaling up standardized formulations, strengthening farmer training on biopesticide use, and embedding herbal-based pest control strategies into agricultural policy frameworks. Overall, this study emphasizes that herbal biopesticides are not only effective in managing pest resistance but also align with long-term goals of ecological balance, food security, and environmental safety.

Pages: 775-779  |  273 Views  85 Downloads