Evaluation of Twenty Maize Germplasms from Belize, French Guiana, Guyana, and Suriname for Resistance to Leaf-Feeding Spodoptera frugiperda1

Abstract

Fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is native to the Americas and a recent invasive pest of Africa, Asia, and Oceania. The insect causes economic damage to maize (Zea mays L.) by feeding on leaf, tassel, and ear tissue. The pest is resistant to several classes of insecticide and Bt-maize grown in certain geographic areas. Native resistance in maize combined with existing control tactics could help overcome control issues. The objective for the study was to evaluate resistance to leaf-feeding fall armyworm in maize germplasm from four countries in the historical range of the pest. Plants grown in the field and artificially infested at the seven-leaf stage were visually scored for leaf-feeding damage at 7 and 14 days post infestation. Scores for Ames 28786 (‘GIN II’) maize germplasm were not different than the resistant check, GT-FAWCC(C5). In 2020 and 2021, 14-day scores for NSL 283834 (‘Guyana 807’) (5.8 ± 0.3 and 4.9 ± 0.3, respectively) were not different than GT-FAWCC(C5) (5.3 ± 0.2 and 4.8 ± 0.3, respectively). The germplasm sources are moderately resistant to leaf feeding by fall armyworm and might be useful to breeding programs developing resistant maize. In one of 2 years of testing, NSL 283833, NSL 283890, and PI 553088 germplasms received 14-day scores <6.0, and further testing is required to determine their ability to resist leaf-feeding fall armyworm. All maize germplasms tested are tropical and require breeding to adapt progeny for additional research in temperate areas.