Evaluating Founding Landraces of Maize Population PI 674097 for Resistance to Leaf-Feeding Spodoptera frugiperda1

A maize (Zea mays L.) pest native to the Americas, the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a recent invasive of Africa, Asia, and Oceania. Resistant to several insecticide classes and toxins of Btmaize, the insect damages maize by feeding on leaf, tassel, and ear tissue. Using native resistance in maize along with existing tactics could improve control outcomes. The objective for the study was to evaluate resistance to leaf-feeding fall armyworm in maize population PI 674097 and founding landraces used to develop this germplasm. Plants grown in the field and artificially infested at the seven/eight-leaf stage were visually scored for leaf-feeding damage at 7 and 14 days post infestation. All scores for NSL 283507, PI 498583, PI 583912, and PI 674097 were less (i.e., more resistant) than the susceptible check, GEMN-0131. In 2022, 14-day scores for PI 674097 were not different than the resistant check, Mp708 (3.6 ± 0.5 and 2.7 ± 0.5, respectively). PI 674097 was variable in its response to fall armyworm leaf feeding with individual plants receiving a range of 14-day scores from 2 (resistant) to 7 (susceptible) across both years of testing. This variability might be useful when selecting for greater resistance to the pest.