Evaluation of XL370A-Derived Maize Germplasm for Resistance to Leaf Feeding by Fall Armyworm1

Abstract

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an economically important insect with larvae damaging maize (Zea mays L.) leaves and ear tissue. The pest has become resistant to several classes of insecticide and Bt-maize grown in some geographical areas. Once discovered and characterized, native sources of maize resistance to this pest could be effectively integrated with existing control tactics. The objective for this study was to test experimental lines derived from maize germplasm XL370A for resistance to leaf feeding by fall armyworm. Plants were grown in the field in 2018 and 2019, artificially infested with fall armyworm, and leaf damage scores recorded. Average 14-day scores for experimental maize lines GEMN-0095 (5.8), GEMN-0096 (5.7), and GEMN-0133 (5.6) were moderately resistant and 7- and 14-day scores for these entries were not significantly different across both years. Cuba 94 was not significantly different from the three entries with the exception of having greater 7-day damage scores in 2019. GEMN-0048 was not resistant but variability was observed in 14-day scores between 4 (resistant) and 8 (susceptible) in individual plants. The experimental lines are adapted for growth in temperate regions and might provide maize breeding programs with useful levels of resistance to fall armyworm.