Evaluation of Maize Germplasm for Resistance against Invasive Insect Pest Fall Armyworm Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

Abstract

Background: Fall armyworm (Spodoptera frugiperda J. E. Smith) is an invasive insect pest of maize that can cause substantial foliar damage and adversely affect crop production. Host-plant resistance offers a sustainable and environmentally compatible approach for managing this pest; however, information on resistance in diverse maize germplasm remains limited. Therefore, identifying resistant genotypes is important for supporting the development of fall armyworm-resistant maize. Aims: The present study screened 25 maize genotypes for resistance to the invasive insect pest fall armyworm under artificial infestation conditions. Study Design: A randomised block design (RBD) with three replications was used. Place and Duration of Study: The study was conducted during Kharif 2025 at the Winter Nursery Centre, ICAR-Indian Institute of Maize Research, Rajendranagar, Hyderabad. Methodology: Fall armyworm larvae were reared on a chickpea-casein-based artificial diet, and first instar neonates were released onto plants at the V5 phenological stage. Leaf damage rating (LDR) was scored on a 1-9 scale at 7, 14, and 21 days after infestation (DAI); genotypes were categorised as resistant (1-3), moderately resistant (3-6), and susceptible (6-9). Results: The LDR at 14 days after infestation varied from 2.58 to 7.34 across genotypes. Three genotypes, CML 71 (2.81), DMRE-63 (2.58), and CML 67 (2.92), were classified as resistant; 19 genotypes were moderately resistant; and three genotypes, MIL 9-1662 (6.2), CM 202 (6.44), and Sarhad HSRB (7.34), were susceptible. Conclusion: The resistant genotypes identified in this study may serve as valuable sources of resistance for incorporation into maize breeding programmes aimed at developing FAW-resistant genotypes.