RELATIONSHIP BETWEEN GROWTH OF CORN-EARWORM AND FALL ARMYWORM LARVAE (LEPIDOPTERA, NOCTUIDAE) AND MAYSIN CONCENTRATION IN CORN SILKS

Plant resistance to insects, specifically antibiotic resistance, offers biologically, economically, and environmentally sound alternatives to pesticides for controlling the corn earworm, Helicoverpa zea (Boddie), and fall armyworm, Spodoptera frugiperda (J. E. Smith), in com, Zea mays L. Our study was done to determine the relationship between maysin concentration in corn silks and growth of corn earworm and fall armyworm larvae. Silks, or methanol extracts from the silks of a large number of corn entries mixed in meridic diets, were evaluated by feeding them to neonate larvae and measuring subsequent larval growth at 8 or 9 d. Silks from several corn entries showed high antibiosis and a high maysin content. A range of highly significant negative relationships between weight of larvae and maysin concentration was observed.