Fall armyworm threatens Asian rice security: A review of sustainable management strategies

Rice (Oryza sativa L.), a primary staple food for billions of people worldwide, faces a growing threat from the invasive fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), in Asia. Given the predominance of small-scale farmers in Asian rice production, which accounts for over two-thirds of global rice output, the region is highly vulnerable to FAW infestations. The FAW’s rapid reproduction, extensive dispersal capabilities, and remarkable adaptability pose significant risks, with the potential for substantial yield losses comparable to those observed in other crops. Recent reports highlight a concerning host shift of the corn-specialized FAW strain towards rice cultivation in Asia. Beyond direct yield losses, FAW infestations can lead to the excessive use of pesticides, posing serious threats to human health and environment safety. Effective and sustainable FAW management in rice is crucial for ensuring long-term agricultural sustainability. Control strategies encompass a diverse range of approaches, including cultural techniques, biological methods, chemical interventions, and habitat manipulation. The absence of rice varieties resistant to FAW underscores the urgent need for accelerated development through genetic engineering. Cultural control practices, such as staggered planting, deep tillage, crop rotation with non-host species, and improved field sanitation, can effectively reduce FAW populations. While promising, methods like trap cropping and push-pull strategies require further field validation in rice systems. Biological control measures utilize natural predators, such as big-eyed bugs and ground beetles, and parasitoids like Telenomus remus and Campoletis sonorensis. Additionally, entomopathogenic agents like Metarhizium rileyi, Bacillus thuringiensis (Bt), and Beauveria bassiana offer environmentally sustainable alternatives to chemical insecticides. While synthetic insecticides remain an essential component of FAW management, the increasing prevalence of pesticide resistance and associated economic losses necessitate a shift towards eco-friendly solutions. The growing resistance of FAW to multiple insecticide classes underscores the urgent need for robust resistance management strategies. This review emphasizes the critical role of integrated pest management (IPM) in combating FAW in Asia, advocating for a balanced approach that prioritises biological control, effective cultural practices, judicious use of insecticides, and sustainable agricultural methods to mitigate FAW damage and ensure long-term rice security for the region.