Integrated Management and Biological Approaches in the Control of Stored Wheat Pests: A Perspective
Wheat (Triticum spp.), a cornerstone of global food security, experiences substantial qualitative and quantitative losses during post-harvest storage due to insect infestations. Certain species of Coleoptera and Lepidoptera are the main pests that cause both direct weight loss and quality deterioration in stored wheat. Conventional control strategies based on chemical fumigants and residual insecticides are increasingly challenged by residue concerns, environmental risks, and the widespread development of insect resistance. This review synthesizes current knowledge on biological control options against major stored-wheat insect pests, based on studies conducted over the past 25 years, including laboratory, semi-field, and commercial-scale investigations, focusing particularly on parasitoids and entomopathogenic microorganisms. In addition to evaluating existing management approaches, it highlights how short-term climatic fluctuations within storage environments may alter pest prevalence and population density, thereby affecting the performance of biological control agents. By linking biological control strategies with climate-related risk factors, this review provides an integrated perspective for improving stored-product pest management under variable storage conditions. The effectiveness of parasitoids (Anisopteromalus calandrae, Lariophagus distinguendus, Theocolax elegans), predators (e.g., Xylocoris flavipes), and entomopathogenic agents [Beauveria bassiana, Metarhizium anisopliae, Bacillus thuringiensis, and entomopathogenic nematodes (EPN)] is comparatively assessed. Evidence indicates that preventative early-release strategies of parasitoids can achieve pest suppression exceeding 80%, while entomopathogenic fungi demonstrate enhanced efficacy when combined with inert dust formulations. However, factors such as grain bulk depth, temperature and humidity fluctuations, and the formation of “hot spots” in commercial silos limit the translation of laboratory success into field-scale effectiveness. The findings suggest that biological control alone may not satisfy the “zero-insect tolerance” standards required in international grain trade. Nevertheless, when integrated with sanitation, physical control measures, pheromone-based monitoring, and advanced application technologies, biological control constitutes a key component of Integrated Pest Management (IPM) programs. Future integration with artificial intelligence-based monitoring systems, nanotechnological formulations, and biotechnological innovations is expected to strengthen the strategic role of biological control in safeguarding stored wheat.