Integrated approaches for the management of invasive fall armyworm, Spodoptera frugiperda (J. E. Smith) in maize

Abstract

Fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is a serious invasive insect pest affecting global maize production. Effective integrated management of FAW is essential to minimize the yield losses. The objective of this study is to determine a suitable package for the sustainable management of FAW by validating the potentiality of various integrated approaches through field trials. In the present study, five different integrated pest management treatments consisted of different components were synthesized and evaluated against fall armyworm in maize-based systems during winter (December 2022–April 2023) and rainy (July–November 2023) seasons. The data on the number of plants damaged, leaf damage rating (1–9 scale), and natural enemies such as spiders, coccinellids, and earwigs were recorded from 20 randomly selected plants at 7 and 14 days after the first and second sprays. Yield data (q ha⁻¹) were recorded at the time of harvest. Treatment 1 consisting of pheromone traps at a rate of 4 per acre with ICAR-NBAIR lures, erection of bird perches at a rate of 10 per acre, seed treatment with Chlorantraniliprole 50 FS at a rate of 5.6 ml per kilogram of seed, and spray application of azadirachtin 1500 ppm at the rate of 5 ml per litre, and Metarrhizium anisopliae with spore count of 1 × 10⁸ cfu/g (1 kg per acre) at a rate of 5 g per litre significantly reduced the per cent plant infestation (12.7) and leaf damage rating (2.1) by FAW larvae compared to untreated control (39.7, 4.1), respectively. The higher natural enemy population (spiders, coccinellids, and earwigs) was also observed in Treatment 1 (8.8) compared to Treatment 5 (4.1) (chemical control). Furthermore, higher grain yield of 51.5 q ha⁻¹ was obtained in Treatment 1 with a cost–benefit ratio of 1:2.1, whereas in untreated control, the yield obtained was 29.0 q ha⁻¹ with a cost–benefit ratio of 1:1.3. The highest per cent of avoidable yield losses of 43.6 was observed in Treatment 1 in comparison with other treatments. Integration of sustainable management approaches reduces the application of chemical insecticides and enhances the population of natural enemies which would be beneficial to maize farmers.