Chemical cues in grain storage: A review on semiochemical types, pest behavior, and control strategies

Abstract

The excessive reliance on synthetic chemical pesticides has led to adverse environmental impacts, prompting the exploration of sustainable alternatives like semiochemicals (pheromones and allelochemicals) for pest management. These chemical compounds offer innovative approaches to controlling stored product insects, which pose significant threats to global food security by infesting and degrading grains and stored food products. This review delves into different kinds of semiochemicals, their action mechanism, and their applications in insect control methods, including mass trapping, mating disruption, attract-and-kill, and push-and-pull strategies. Recent advancements at the molecular level, particularly in understanding pheromone receptors, have enhanced insights into insect recognition and response to chemical signals. Different kinds of semiochemicals and their roles in managing stored grain pests belonging to Coleoptera, Lepidoptera, and Psocoptera are discussed. Additionally, the effectiveness of various pheromone-based traps, such as sticky, funnel and cone, pitfall, and light-activated traps, in grain storage monitoring are discussed, along with insights from field and laboratory case studies. Integration of pheromone traps with biological, chemical, and mechanical control methods is examined to highlight the potential for holistic pest management strategies. Despite their effectiveness, challenges such as environmental variability and species-specific responses persist. Future directions emphasize innovations in pheromone synthesis, trap design, and interdisciplinary approaches to enhance scalability and applicability across diverse storage ecosystems. This review underscores the critical role of semiochemical-mediated techniques in reducing stored product losses, offering a sustainable and effective alternative to chemical pesticides.