Effect of planting date and hybrid selection on Helicoverpa zea and Spodoptera frugiperda (Lepidoptera: Noctuidae) damage on maize ears in northeastern Mexico.

Abstract. This study determined the impact of planting date and kernel color variety (yellow vs. white) on the incidence of the maize, Zea mays L., ear insects corn earworm, Helicoverpa zea (Boddie), and fall armyworm, Spodoptera frugiperda (J.E. Smith), in northern Tamaulipas, Mexico, from 2006 to 2009. Eight hybrids from six to 11 planting dates from late December to early March were evaluated each year. Overall, corn earworm and fall armyworm comprised 89 and 11%, respectively, of all Lepidoptera larvae inspected at the maize milk stage. Damage at harvest by ear insects was greater during the earlier planting dates (December), diminished during the intermediate dates (January–early February), and increased again at later planting dates (late February–March). Damage to ears of yellow maize hybrids was 53% greater than damage to white hybrids, probably because of a differential grain hardness and husk wrap. However, H-443A, a yellow hybrid with good grain and husk characteristics for the region was less ...