Quantitative impacts of different planting arrangements on the populations of natural enemies in soybean

Natural biological control is an important alternative for the control of insect pests using natural enemies that occur naturally in agroecosystems. The potential of these insects can increase when they are adequately managed. Thus, the objective of this study was to quantify the populations of natural enemies in soybean cultivars with different growth habits planted in different arrangements. The experiment consisted of eight treatments: four planting arrangements and two soybean cultivars, with four replicates. The populations of natural enemies were evaluated from the vegetative stage V3 to crop harvest using a shaking-cloth. A population survey of the beneficial arthropods present on the soil surface was performed in the reproductive stages R2 and R3 with the installation of modified pitfall traps. The main natural enemies that occurred in the culture were Class Arachnida, Order Heteroptera, Order Hymenoptera, Order Coleoptera and Order Dermaptera. The populations of the natural enemies assessed using the shaking-cloth did not show significant differences. However, in the evaluations with the modified pitfall traps in the reproductive stage R3 in the crossed arrangement, the populations of the Coleoptera and Dermaptera orders were higher in the determinate cultivar than in the indeterminate cultivar.