Efecto de la composición del paisaje sobre la abundancia de artrópodos predadores e insectos plaga en el cultivo de soja

In Uruguay, soybean [Glycine max (L.) Merril] is currently the predominant summer crop in agricultural-pastoral landscapes. The area planted with soybeans in the country has been evolving increasingly over the last 20 years together with a process of agricultural intensification. This phenomenon caused the loss of landscape heterogeneity due to the increase in area of annual crops and the removal of semi-natural habitats. The agricultural expansion occurred to the detriment of sites of permanent vegetation, such as the natural fields, which act as refuge sites for natural controllers, determining a possible increase in pest pressure and the use of insecticides. In the present work, we evaluated the effect of landscape composition on the abundance of predatory arthropods and pest insects in soybean fields. The hypothesis was the following: predominance of agriculture in the landscape negatively affects predators and increases the abundance of pest insects in soybean fields. It was concluded that the floristic composition of the surrounding landscape (1km) differentially affects the abundance of the main groups of predatory arthropods. Most simple landscapes with a predominance of agriculture (greater than 50%) have a lower abundance of total predators and the natural field was positively associated with spiders and predatory hemipterans. The results obtained show that the landscape composition is important in predator arthropod population dynamics and certain pest insects. Therefore, when the man intervenes in said landscape, this also has an impact on this important link in the food chain.