The augmentation of natural enemies against agricultural pests is a common tactic undertaken to minimize crop damage without the use of chemical pesticides. Failures of this strategy may result from (i) Allee effects acting on biological control agent; (ii) trophic interactions between the released control agent and native species in the local ecosystem; (iii) excessively rapid spreading agents. To investigate the interplay of these mechanisms in pest biocontrol efficiency in the context of intraguild predation (IGP), we develop a one-dimensional dynamical model of a spatial, tritrophic food web with intraguild predation. We show that the agent’s diffusivity (i.e., agent’s dispersal speed), and intraguild predator’s addition of alternative food sources are important factors in determining the success or failure of pest biocontrol. These results are obtained for spatially explicit models by considering the speed of dispersal of the control agent and the pest. Feedback from theoretical models as the one constructed in this work can provide useful guidelines for practitioners in biological control.

增加天敌抵抗农业害虫是一种不使用化学杀虫剂就可最大程度地减少农作物损害的常用策略。该策略的失败可能是由于（i）作用于生物防治剂的Allee效应；（ii）释放的控制剂与当地生态系统中的本地物种之间的营养相互作用；（iii）铺展剂过快。为了研究在公会内捕食（IGP）的情况下这些机制在害虫生物防治效率中的相互作用，我们开发了一种具有公会内捕食的空间三营养食物网的一维动力学模型。我们表明，媒介物的扩散性（即媒介物的扩散速度）和行内捕食者添加替代食物来源是确定害虫生物防治成功与否的重要因素。这些结果是通过考虑控制剂和有害生物的扩散速度而在空间上明确的模型中获得的。作为这项工作构建的理论模型的反馈可以为生物学控制领域的从业人员提供有用的指导。