The long-term objective of this project is to reduce, inhibit, or eliminate toxigenic and pathogenic microbes (i.e., mycotoxigenic fungi or pathogenic bacteria) by utilizing intervention techniques such as biological control. Specifically, during the next five years we will focus on the following interrelated objectives. Objective 1: Develop and implement control measures to reduce, eliminate, or detect contamination of toxin producing fungi of tree nuts, for example the use of host plant- or fungal-derived semiochemicals to attract or control insect pests, or use of sterile insect techniques to decrease insect pest populations. • Sub-objective 1A: Use of host plant- or microbe-derived volatile semiochemicals to attract or control insect pests. • Sub-objective 1B: Use of sterile insect techniques to decrease insect pest populations. Objective 2: Elucidate principles of microbial ecology and develop biological control measures to inhibit pathogenic and toxigenic microorganisms, particularly fungi, and can include research on the isolation and development of new biocontrol agents and formulations to control or prevent toxigenic microbes, or survey, identify, and determine ecology of microbial populations for control strategies such as competitive microorganisms. • Sub-objective 2A: Isolate biocontrol agents that prevent pathogenic/toxigenic microbes from colonizing crops. • Sub-objective 2B: Risk analysis of waste used as fertilizers for pathogen/toxigen contamination. • Sub-objective 2C: Develop new biocontrol agents and formulations to control toxigenic fungi, and to survey and characterize populations of Aspergilli. • Sub-objective 2D: Determine ecology of black-spored toxigenic Aspergilli and develop control strategies using competitive microorganisms. Objective 3: Discover natural chemical compounds that enhance the efficacy of established microbe intervention strategies, for instance augment the activity of antimicrobial agents/treatments against pathogens via target-based application of natural chemosensitizing agents.