Assessment of Bioefficacy of Beauveria bassiana Indigenous Products on Pulse Beetle (Callosobruchus chinenesis) to Minimize Post Harvest Losses

Pulses, notably mung beans, play a pivotal role in Indian agriculture and ensure food security. However, the challenge of post-harvest losses due to storage pests such as the pulse beetle (Callosobruchus chinensis) remains substantial. Conventional synthetic pesticides, while effective, present risks to both human health and the environment. Consequently, there is growing interest in alternative methods such as biological control and botanical extracts. Beauveria bassiana, an entomopathogenic fungus, along with botanical extracts from neem, tobacco, and ginger, show promise in combating these pests. An experiment assessed the effectiveness of botanical insecticides against C. chinensis, a notorious stored grain pest. Prayagraj belongs to sub-tropical climate zone with severe winter and harsh summer along with humid monsoon. Summer lasts from March to September with daily highs reaching up to 48 °C in the dry summer (from March to May) and up to 40 °C in the hot and extremely humid monsoon season (from June to September). The research evaluated different treatments: T1 (Azadirachta indica Leaf Extract 4% + Beauveria bassiana 4%), T2 (Nicotiana tabacum Leaf Extract 4% + Beauveria bassiana 4%), and T3 (Zingiber officinale Extract 4% + Beauveria bassiana 4%). The results demonstrated that T1 exhibited the highest mortality rates across all larval stages of C. chinensis. Specifically, T1 showed 71.07% mortality at 24 hours, 94.51% at 48 hours, and 90.57% at 72 hours for the 1st instar larvae. Similarly, for the 3rd instar larvae, T1 resulted in 70.36% mortality at 24 hours, 75.14% at 48 hours, and 89.24% at 72 hours. The 5th instar larvae also showed significant mortality rates with T1 treatment. Botanical insecticides, particularly those incorporating A. indica, demonstrate significant potential for safeguarding pulses from pest infestation during storage. Plant-based insecticides offer environmentally friendly, biodegradable alternatives that safeguard non-target organisms. To advance the development of novel compounds for sustainable pest management in stored grains, future research should investigate a range of factors, including mammalian toxicity, insecticidal mechanisms, seed viability, and chemical stability. In summary, plant-based insecticides provide a sustainable strategy for grain protection, effectively controlling pest populations while reducing environmental harm.