Natural pest control results from ecological functions like predation or parasitism. Such functions are supplied by an array of natural enemies embedded in a large community of interacting species. In this chapter, we discuss the extent to which natural enemy composition affects pest demography and we highlight the importance of considering how species interact with each other to understand the processes behind pest control. More specifically, we emphasize the importance of identifying the emergence of positive or detrimental interactions in trophic networks by combining both horizontal and vertical approaches. In addition, we show that knowledge of community assembly rules across agricultural landscape scales is in its infancy and that the relative contributions of stochastic and deterministic processes on natural enemy assemblages remain poorly understood. For these reasons, we argue that community ecology and network ecology should help us enhance natural pest control services within agricultural landscapes.