Sesamia nonagrioides (Lefebvre) and Ostrinia nubilalis (Hübner) are the main maize (Zea mays L.) pests in Mediterranean countries. To develop insect-resistant cultivars, it is helpful to know the genetic control of the resistance. Our objective was to determine the genetic control of the resistance to both borers. For each of two crosses (EP59 x P51 and 15125 x EP61), six generations were evaluated (P1, P2, F1, F2, BC1, and BC2). Genetic effects x environment interactions were not significant. For the O. nubilalis resistance traits; both crosses fitted an additive-dominance model. EP59 x P51 had important dominance and additive effects, whereas for 15125 x EP61 we did not detect significant genetic effects, but significant year effects were detected. For S. nonagrioides infestation, both crosses fitted to an additive-dominance model. There were additive effects for most traits in EP59 x P51. The cross I5125 x EP61 showed significant dominance effects for several traits. Resistance to both corn borers fit an additive-dominance model, but genetic effects depend on the cross evaluated. In the resistance to S. nonagrioides, additive effects were important for shank resistance, which is a useful trait for avoiding S. nonagrioides damage on the ear. Early sowings are recommended to make good use of the resistance to both corn borers. In the late sowings, damage is so high that resistant plants are not able to control the pest.

Flint maize, Zea mays L., varieties provide some interesting agronomic characteristics and kernels that possess a better ability than other kernels for developing high-quality flour. The pink stem borer, Sesamia nonagrioides Lefebvre, is an important constraint for the maize crop in Mediterranean regions. The objective of this work was to identify a "flint x flint" heterotic pattern that would perform well under artificial infestation by S. nonagrioides. A 10-population diallel was evaluated under infestation by S. nonagrioides in 2 yr. Variety effects were the only significant effects involved in stem and ear resistance to S. nonagrioides attack. Variety effects and average heterosis effects were the only significant effects for grain yield under artificial infestation conditions. Considering variety effects and cross-performance, the heterotic pattern Basto/Enano levantixo x Longfellow (BA/EL x LO) would be recommended for obtaining flint maize hybrids tolerant to S. nonagrioides attack because BA/EL had the most favorable variety effects for stem resistance, LO exhibited the most positive variety effects for grain yield, and the cross BA/EL x LO yielded significantly more than the remaining crosses.