Technical Abstract: Stone fruit and tree nuts such as peach, pecan, almond and pistachio constitute important North America crops. These crops harbor various insect pests. A number of these pests may be amenable to microbial control using entomopathogenic nematodes or fungi. This chapter summarizes techniques that can be used to evaluate the efficacy of these biopesticides for control of stone fruit and tree nut pests under field conditions. Insect pests that may be amenable to control with entomopathogens include pecan weevil (Curculio caryae), plum curculio (Conotrachelus nenuphar), navel orangeworm (Amyelois transitella), peachtree borer (Synanthedon exitiosa), and fruit flies (e.g., Anastrepha ludens and Rhagolites indifferens). The manuscript addresses protocols for selecting test sites, plot design, preparation, application and assessment. Generally, the biopesticides must be applied under environmental conditions that avoid excess exposure to ultraviolet light, and nematodes should be applied to soil under moist conditions.