Pest species that are enhanced by cover crops used in no-tillage farming can cause damages to subsequent crops of economic importance planted into cover crops stubble. In the 2006/2007 growing season, in Dourados, MS, Brazil, a study was carried out to assess the arthropod fauna in three soybean no-tillage systems: unseeded vegetation-soybean, pearl millet-soybean and sorghum-soybean. During the soybean pre-planting season and the early soybean season, the incidence of pests and natural enemies was assessed in 1 m 2 of the cover crops and later on their respective stubble with soybean seedlings in development using a wood made frame square ("wood square" sampling method). The most abundant species at the soybean pre-planting season were caterpillars of Mythimna ( Pseudaletia) sequax and Mocis latipes (Lepidoptera: Noctuidae), and adults and nymphs of the predator Doru luteipes (Dermaptera: Forficulidae), showing a significant population increase on the pearl millet green cover crop. After the cover crops desiccation the incidence of Lagria villosa (Coleoptera: Lagriidae) species was significant on sorghum and pearl millet stubble and the genus Agrotis sp. (Lepidoptera: Noctuidae) on sorghum cover. Thus, the bioecology of pests and natural enemies associated with pearl millet as cover crop might be considered on the development of Integrated Pest Management (IPM) programs in conservation farming systems.
