ABSTRACT

Soybean (Glycine max (L.) Merrill) is a relatively new crop in the tropics. In spite of this, dynamics of the insect fauna adaptation rapidly occurred and is still on course, as time of cultivation increases and new areas are incorporated into the production process. To illustrate this, an overview in the literature was done taking as an example the dramatic expansion of soybean in Brazil, and the records on surveys of insect pests and their natural enemies (parasites and predators) during the last 30 years. Data in the literature indicate that there was a general trend toward an increase in the number of species adapted to the crop, and that sometimes this dynamic adaptation led to disappearance or accomodation in low levels of once common pests. Beyond the expansion of soybean with subsequent adaptations of native herbivores and their associated carnivores, several other factors are mentioned as responsible for these changes in the entomofauna which include: use of new more selective insecticides, reduced use of insecticides; implementation of biocontrol agents, such as virus to control the velvetbean caterpillar, Anticarsia gemmatalis Hübner, and egg parasitoids to control stink bugs; and massive adoption of alternative systems of soybean cultivation (no-tillage and minimum tillage), with great impact on soil inhabiting insects. The implementation of integrated pest management (IPM) with strong emphasis on biocontrol is leading the system to a more balanced situation, and pests outbreaks are in general restricted to newly cultivated areas where the natural equilibrium has been disrupted.