The cultivation of genetically modified crops in Brazil has led to the need to assess the impacts of thistechnology on non-target species. Under field conditions, the potential effect on insect biodiversity wasevaluated by comparing a homogeneous corn field with conventional and transgenic maize, expressingdifferent Bt proteins in seven counties of Minas Gerais, Brazil. The richness pattern of non-target insectspecies, secondary pests and natural enemies were observed. The results do not support the hypothesisthat Bt protein affects insect biodiversity. The richness and diversity data of insects studied were depend-ent on the location and other factors, such as the use of insecticides, which may be a major factor wherethey are used.201

The objective of this work was to evaluate the biological variables of Spodoptera frugiperda on species of cover crops. The experiments were conducted in laboratory and greenhouse using the following species: sunflower (Helianthus annuus), sun hemp (Crotalaria juncea), brachiaria (Brachiaria decumbens e Brachiaria ruziziensis), millet (Pennisetum americanum), black oat (Avena stringosa), white lupin (Lupinus albus), forage turnip (Rafanus sativus) and maize (Zea mays). In laboratory the S. frugiperda larval survival varied from 57%, on L. albus, to 93% on H. annuus and the survival of the pre-imaginal phase varied from 45% on B. decumbens to 81.6% on Z. mays. On C. juncea the larval biomass was lower and the development period of the young and larval stage was higher. The adaptation index was less on C. juncea in greenhouse and laboratory. In greenhouse the larval survival at 14 days was similar for all plants and at 21 days was the lowest on C. juncea. There was less accumulation of biomass at 14 days on C. juncea and at 21 days on C. juncea and A. stringosa. Regarding damage, C. juncea presented less susceptibility to Spodoptera frugiperda attack, which together with the other evaluated parameters, indicated this plant as the most appropriate for soil cover before cultivation of maize.