There are several biopesticides based on entomopathogenic fungi available in the market for use against insect pests in greenhouse ecosystems.Although most are compatible for use with predators and parasitoids in greenhouse ecosystems,much more research is needed to determine the intraguild interactions for each combination of host, pathogen, predator, and parasitoid.Our research has demonstrated that, although direct effects on the predators could be demonstrated in laboratory bioassays, different results were found under greenhouse conditions, indicating that results obtained in the laboratory may be a poor predictor of what occurs in the greenhouse.In both cases, additive effects were obtained under greenhouse conditions,demonstrating compatibility. In addition, there is increasing evidence that entomopathogenic fungi have significant potential for dual management of invertebrate pests and plant pathogens.Our studies demonstrated that 3 species of Lecanicillium had significant effects on both aphids and cucumber powdery mildew, Sphaerotheca fuliginea;that the fungus Paecilomyces fumosoroseus was compatible with a mirid predator,Disyphus hesperus,when used concurrently against greenhouse whitefly,Trialeurodes vaporariorum;and that Lecaniciullium longisporum was compatible with a predatory midge,Aphidoletes aphidimyza when used concurrently against green peach aphids.