Success Stories in Microbial Management of Insect Pests in Oilseed Crops: Achievements and Challenges

Abstract

Oilseed crops—including Brassica species (rapeseed/mustard), sunflower (Helianthus annuus), soybean (Glycine max), sesame (Sesamum indicum), and groundnut (Arachis hypogaea)—are vital components of global agricultural economies, providing essential vegetable oils and protein meals. However, sustainable production is severely limited by complex insect pest complexes, including Plutella xylostella, Helicoverpa armigera, Bemisia tabaci, Lipaphis erysimi, and Spodoptera litura. The historical over-reliance on synthetic chemical insecticides has precipitated severe ecological repercussions, including insecticide resistance, residue accumulation, secondary pest outbreaks, and biodiversity loss. Microbial management using entomopathogenic bacteria (Bacillus thuringiensis), fungi (Beauveria bassiana, Metarhizium anisopliae, Lecanicillium lecanii), viruses (Nucleopolyhedroviruses), and entomopathogenic nematodes (Steinernema and Heterorhabditis spp.) offers a ecologically sound, highly specific alternative. This review synthesizes global success stories in microbial biocontrol across major oilseeds, with an in-depth examination of achievements, progress, and future prospects in Pakistan and South Asia. Key methodological advances in formulation technology, genomics, and integrated pest management (IPM) are critically analyzed, alongside persistent field challenges such as abiotic stress degradation, slow speed of kill, regulatory hurdles, and commercial supply chain constraints. Recommendations for policy reform, regional cooperation, and biotechnological integration are articulated.