Unveiling the Impact of Mythimna seperata Walker (Lepidoptera: Noctuidae) on Agriculture: Insights into Host Range Biology and Biological Control: A Review

Abstract

The Oriental armyworm scientifically referred to as Mythimna separata poses a significant threat to cereal crops across East Asia, South Asia, and Australia, resulting in notable agricultural losses. Recent reports indicate its widespread presence in 21 Asian countries and its establishment in Europe (Russia) and Oceania (Australia, Cook Islands, Fiji, New Caledonia, Norfolk Island, New Zealand, Papua New Guinea, Samoa, Solomon Islands, Tonga, and Vanuatu). M. separata undergoes a comprehensive metamorphic life cycle, progressing through stages of egg, larva, pupa, and adult. The larvae are highly voracious, causing significant harm to diverse crops This pest targets a wide range of host plants spanning 18 families, with the majority belonging to Poaceae (44 species), Brassicaceae (10), Cucurbitaceae (9), and Fabaceae (8), exacerbating agricultural damages. The voracious feeding habits of M. separata larvae lead to significant crop damage and reduced yields across various crops. Its adaptability to diverse environments and broad host range further amplifies its impact on agriculture. The challenges in predicting and controlling outbreaks stem from its strong flight capabilities, high reproductive rates of females, and voracious feeding behavior during later larval stages. Traditionally, insecticide application has been the primary method for controlling M. separata. However, concerns regarding health risks, ecological disruptions, rising costs, diminishing efficacy of some products, and adverse effects on non-target organisms and human health highlight the need for environmentally sustainable pest management strategies. Biological control, involving the utilization of natural enemies such as insects, viruses, fungi, bacteria, nematodes, mites, and spiders, has emerged as a vital approach for managing insect pests while preserving ecological balance. Given the complex challenges posed by M. separata, implementing a holistic approach that integrates biological control methods holds promise for effective pest management. This approach aligns with principles of environmental sustainability and biodiversity conservation within agro-ecosystems.