Otimização do controle de Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) por meio do parasitoide Cotesia flavipes (Cameron, 1891) (Hymenoptera: Braconidae) visando a redução de custos

Abstract

Brazil is the world’s largest producer of sugarcane. However, this agricultural crop is attacked by pests, especially Diatraea saccharalis. Its control in Brazil is carried out mainly by the action of the caterpillar parasitoid, Cotesia flavipes. Therefore, understanding how the interaction between these two species occurs is vital to increase the effectiveness of this control. This thesis’ goals are to improve the description of the dynamics among populations and to transform this information into a tool to optimize the biological control of this pest, focusing at the cost reduction for the farmer. In order to describe the dynamics of these two populations, the Lotka-Volterra model and a multi-agent simulation were employed. Through the first model, the characteristics of the differential equations system were obtained, and treatment suggestions to be field tested were presented, in case the pest population size is known. The multi-agent simulation, which by its construction presents more realistic characteristics compared to the Lotka-Volterra model, played a crucial role in the description of the pest in its life cycle phases, where behaviors not observed in the first model were obtained. Afterwards, biological control optimization was developed, taking into account the financial damage that the pest causes in a given period and the cost of its treatment. In order for this procedure to become a useful tool in the farms, an improved survey method has also been proposed. Finally, the results developed here present new solutions so that the biological control of this main sugarcane pest can be carried out more effectively, contributing to the reduction of the employment of chemical products and increasing the competitiveness of this Brazilian industry.