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Abstract
Understanding how arthropod communities are structured and how environmental stressors such as farming management practices act as ecological filters in this process is essential to advancing sustainable arthropod management. In this dissertation, I used the pecan system as a model to answer basic and applied questions related to how structural and chemical interventions influence arthropod communities in agroecosystems. This work integrates experimental, observational, and molecular approaches. Initially, I examined shifts in arthropod population abundances in response to canopy hedge pruning, revealing that pest and natural enemy groups responded in a case-specific manner. Building on these patterns, I evaluated how farming-induced stressors influenced multi-trophic species interactions, demonstrating that predation and parasitism dynamics were shaped not only by natural enemy abundance, but also by their spatial and temporal alignment with prey, which is affected by common farming practices. Further, I characterized hidden arthropod communities within Phylloxera-induced galls in pecan leaves, employing dissection and DNA metabarcoding to uncover the diversity and structuring of these enclosed systems. Communities inhabiting galls were diverse, and their structure was shaped by gall phenology, providing insight into the ecology of gall systems and how these microhabitats respond to farming-induced stress. These findings also position Phylloxera galls as a promising model for studying community assembly processes under managed conditions. Finally, I applied ecological insights gained from the pecan canopy system to investigate the temporal and spatial dynamics of Auchenorrhyncha herbivores, a group relevant to disease transmission in pecans. Their abundance reflected seasonal and vertical stratification patterns, with farming practices interacting with their activity over time and across canopy layers. Together, these studies contribute to a broader understanding of how management-induced environmental changes interact with habitat structure to shape community composition, multi-trophic interactions, and ecological function across multiple scales in agroecosystems.