Interest in temperate agroforestry has increased substantially over the past several years because of its potential as an environmentally positive, sustainable, and potentially profitable set of land use practices. Knowledge of the complex interactions among trees, crops and their associated fauna is necessary to determine the viability of a particular agroforestry practice. While a significant amount of research has been conducted on the ecological interactions among components of tropical agroforestry practices, little information is available on these interactions in the temperate regions of the world. Agroforestry’s effect on insect populations, both pests and beneficials, in temperate alley cropping practices is particularly lacking. We have conducted a series of studies in intercropped alfalfa to determine this agroforestry practice’s impact on pest populations, particularly the alfalfa weevil and its natural enemies. In general, parasitism rates of alfalfa weevil larvae are higher in alley cropped alfalfa versus monocropped alfalfa.