Intensidades de perdas, ataque de insetos-praga e incidência de inimigos naturais em cultivares de milho em cultivo de safrinha

Abstract

This work aimed at to study the intensities of losses and densities of insect pests and natural enemies to 49 cultivars on the late maize (Zea mays L.) cultivation in Coimbra, Minas Gerais State, Brazil. The medium productivity of the maize cultivars was of 3438.74 kg/ha. The most productive cultivars were Traktor, CDX98D06, CO9621, OC705 and 97TR61. It happened 29,62% of losses in the productivity of the cultivars and the critical component of losses was the grain. The key factor of losses was the attack of Sitophilus zeamais (Motsch., 1865) (Coleoptera: Curculionidae) to grain. The insect pests with highest densities on the plants were Dalbulus maidis (DeLong & Wolcott, 1923) (Homoptera: Cicadellidae), adults of Diabrotica speciosa (Germ., 1824) (Coleoptera: Chrysomelidae) and larves of Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae). The most abundant natural enemy was the predator Doru luteipes (Scudder, 1876) (Dermaptera: Forficulidae). The densities of those insects were similar to cultivars except for D. maidis. SHS5060, COE9994, HT8A97, NB6077, Z8550, CD3351, Maister, AG122, HS12L1133, HT47C, 97TR61, CDX98D04 and A975 were the cultivars less attacked by D. maidis.