Resistance to insects

Abstract

Soybeans are attacked by several species of sucking and defoliating insects, and the sucking insects are now the main pest of the crop in tropical regions. Each year, insect damage is becoming more frequent considering the high number of species present in the crop due to the lack of adequate pest monitoring and the development of insects resistant to the insecticides. The chemical method has been widely used in insect control. However, some molecules have already been banned, others are in the process of banning, and the launch of new products is time-consuming. In this aspect, the use of resistant genotypes can be an alternative or a substitute for the chemical control of insects offering a series of advantages, both from an environmental and economic point of view. However, one of the main obstacles to obtaining resistant genotypes is related to low heritability of the traits associated with insect resistance and also with grain yield, a fact that hinders the development of resistant cultivars. Another aspect is that farmers do not accept resistant genotypes with lower yield potential than cultivars available for cultivation. Thus, in this chapter, the authors present a general discussion about the use of genetic resistance, without the use of transgenes, to obtain new soybean cultivars that highly yield and are resistant to the main pest insects in Brazil.