Dichelops melacanthus foi avaliado em condições con troladas (60 ± 10% UR e fotoperíodo de 14/10 h L/E) em três temperaturas constantes (19, 25, e 31 ± 2 °C). Vagens frescas da soja MON 87701 x MON 89788 e de sua isolinha não-Bt (A5547) foram oferecidas a ninfas e adul tos. A biologia de T. podisi foi estudada nessas mesmas condições controladas de UR, mas apenas na temperatura padrão de 25 ± 2 °C. Em geral, o desenvolvimento de D. mela canthus foi melhor nas temperaturas mais altas, as quais aceleraram o desenvolvimento do percevejo, mas sem afetar os parâmetros biológicos da fase adulta. Não houve influência da soja-Bt na biologia da praga em nenhuma das temperaturas estudadas, o que mostra que D. melacanthus não é afetado pela soja transgênica. O parasitoide de ovos T. podisi também não foi impactado quando parasitou ovos da praga alimentada com soja MON 87701 x MON 89788, com resultados semelhantes àqueles obtidos na soja isogênica não-Bt. Portanto, este estudo comprova que D. melacanthus é favorecido por temperaturas mais altas (31 ± 2 °C), e que soja-Bt MON 87701 x MON 89788 não afeta o desenvolvimento desta praga assim como de seu parasitoide T. podisi.

Dichelops melacanthus was studied under controlled conditions (60 ± 10% RH and 14/10 h L/D photoperiod), and three constant temperatures (19, 25, and 31 ± 2 °C). Fresh pods of MON 87701 × MON 89788 soybeans and its near non-Bt isoline (A5547) were supplied to nymphs and adults. The biology of T. podisi was studied in the same controlled RH conditions, but only at the standard temperature of 25 ± 2 °C. Overall, the development of D. melacanthus was better at higher temperatures, which accelerated the development of the stink bug without affecting adult biological parameters. No influence of Bt-soybeans on the biology of the pest was observed in any temperature studied, which shows that D. melacanthus is not affected by this transgenic soybean. The egg parasitoid T. podisi also was not harmed when it parasitized eggs of the pest fed with MON 87701 × MON 89788 soybeans, with similar results to those obtained in non-Bt isogenic soybeans. Thus, this study demonstrates that D. melacanthus is favored at high temperatures (31 ± 2 °C), and that neither did MON 87701 × MON 89788 soybean pods affect the development of the pest nor its parasitoid T. podisi.

Este estudo objetivou avaliar a biologia larval de Heliothis virescens em soja MON 87701 x MON 89788 e na soja convencional não Bt. De forma geral, o impacto da soja MON 87701 x MON 89788 sobre H. virescens foi evidenciado em todos os bioensaios, com 100% de mortalidade larval, independente da estrutura (folha ou vagem) consumida pela praga. As lagartas pequenas (1° e 3° ínstar) demonstraram que são incapazes de danificarem vagens verdes de soja, independente de ser Bt ou não Bt. As lagartas grandes (5° ínstar) que se alimentaram de soja MON 87701 x MON 89788 consumiram três vezes menos soja comparativamente às desenvolvidas em soja não Bt, além de resultar em menor longevidade e viabilidade larval. No último experimento, as lagartas grandes de H. virescens ocasionaram injúrias na ponteira da soja convencional, verificando-se que a praga se desloca rapidamente para esta região da planta. Entretanto, a soja MON 87701 x MON 89788 é uma eficiente ferramenta no controle de H. virescens.

This study aimed to evaluate the larval biology of Heliothis virescens in soybean MON 87701 x MON 89788 and its isogenic non-Bt. In general, the impact of soybean MON 87701 x MON 89788 on H. virescens was evidenced in all bioassays, 100% larval mortality, independent of the structure (leaf or pod) consumed by the pest. The small larvae (1st and 3rdinstar) demonstrated that they were unable to damage fresh pods of soybean, regardless of whether Bt or not Bt. The large larvae (5th instar) fed on soybean MON 87701 x MON 89788 soybeans consumed three times less compared to larvae fed on non-Bt soybeans, and resulted in reduced longevity and larval survival. When soybean plants were infested with 5th instar larvae, H. virescens caused injuries in the steams of the conventional soybean. It was recorded that the insects moves quickly to this region of the plant. However the soybean MON 87701 x MON 89788 was an effective tool in controlling H. virescens.

The host selection for oviposition by Spodoptera frugiperda (J.E. Smith) among corn, millet, cotton and soybean, and its relationship with the biological characteristics were investigated. Free and non-choice tests for oviposition using plots containing five plants each, from each host in plastic greenhouse, resulted in similar oviposition preference among the host plants. In addition, selected biological characteristics of S. frugiperda were determined in the laboratory with larvae feeding on host leaves, and the combination of leaf and cotton boll. Neonate larvae exhibited low success of colonization on cotton boll compared to the leaves of all other hosts. Spodoptera frugiperda fed only on cotton bolls exhibited longer larval and pupal development, and longer adult life span; however with similar egg production. Larvae fed cotton leaves during six days and then transferred to cotton bolls, however, exhibited development and reproduction similar to those reared on corn or only on cotton leaves. Therefore, the variations on immature stages of S. frugiperda were not related with host selection for oviposition which was similar among the studied hosts. Based on our data, the millet as a winter, rotational, and cover crop is a potential host for S. frugiperda, while leaves and cotton bolls were diets of intermediate suitability as compared to corn and soybean leaves.