Fatores que influenciam a eficiência do controle biológico de predadores em cultivos agrícolas

Abstract

Pests cause the loss of production of the main crops in the world. Pest biological control by natural enemies in crops can mitigate these damages. Several factors may influence biological control, such as the identity and diversity of predators. However, climate and crop stability are neglected. Here, we aim to understand the effect size of biological control on pest suppression and productivity. We also aim to understand if climate and crop stability (perennial or annual) affect the effect size. In this way, we did a meta-analysis to investigate the effect of predators exclusion (e.g., arthropods, birds, and bats) on pest suppression and productivity. We included in our meta-analysis 61 studies and 125 effect size measures on pest suppression and 16 studies with 19 effect size measures on crop productivity. In general, the predators were efficient on pest suppression as well as in cascading effect, benefiting crop productivity. The effect size on pest suppression was larger in studies with multiple bird predators than just one. The pest suppression wasn’t larger in perennial crops than in annuals. Although crop productivity was larger in perennial crops. In addition, the predators were more efficient in sites with more rainfall seasonality. Predation intraguild on arthropods may be a possible explanation for larger effect in pest suppression in studies with multiple bird predators. Our results demonstrate that rainfall seasonality, crop stability, and predator diversity are factors that modulate the effect of biological control. Further investigation on other predator groups (e.g., bats) and cascading effects are needed.