ABSTRACT Corn, Zea mays (L.), is one of the most expressive crops in Brazil, due to its wide-ranging uses as animal feeding, biofuel production or used for human consumption. However, there is a huge gap between the actual yield and the natural yield potential of the crop, due to insects’ attack. Leptoglossus zonatus (Dallas) (Hemiptera: Coreidae) is a key corn pest in seed producing regions, due to its attack on corn ears. Plant resistance is a valuable tool for Integrated Pest Management systems and may maintain insect populations at a level that is below an economic or damage threshold. This study aimed to evaluate the biological performance of L. zonatus in different corn genotypes, under laboratory conditions, searching for possible characterization of antibiosis/antixenosis. To achieve this goal, ten nymphs (1st instar) were transferred to polyvinylchloride (PVC) ring containing a corn ear (R6) of each genotype. Each ring corresponded to one replicate, for a total of five replicates per genotype in a completely randomized design. The parameters assessed included the duration of each instar, nymphal period, nymphal survival (%), percentage of mortality of each nymphal stage, adult longevity, and adult weight. The results demonstrate that XB 8018 Bt, 30F53, IAC Airan, XB 8030 and 30F53 YHR genotypes reduced the mean survival and caused high mortality of L. zonatus nymphs at the second instar (above 75.00%) indicating the occurrence of antibiosis/antixenosis. The higher mortality rates were observed at the second nymphal instar.

ABSTRACT The silverleaf whitefly Bemisia tabaci biotype B is one of the most important sucking pests of common bean, which causes severe damages and requires frequently synthetic insecticides spraying to protect crop productivity. The use of common bean cultivars resistant to whitefly attack is an important strategy within an integrated pest management (IPM) program. The biological development of B. tabaci confined to 17 bean genotypes was evaluated in greenhouse trials to verify the occurrence of antibiosis. Whitefly adults were released on plants of these genotypes to oviposit, afterward the incubation period of eggs, nymphal period, complete development period (egg–adult), and viability of the silverleaf whitefly nymphs were recorded. As main results, genotype CHIP 300 prolonged the developmental period from egg to adult (~10 days) and BRS Estilo, Arcelina 4, IPR Garça, Tybatã, CHIP 300, IPR Eldorado, H96A102-1-1-1-52, SCS-202-Guará and CHIB 06 caused nymphal mortality, suggesting high levels of antibiosis and/or antixenosis. These genotypes may be helpful in common bean breeding programs aimed at developing commercial cultivars resistant to B. tabaci biotype B.