Orius tristicolor (White) (Hemiptera: Anthocoridae) is both predaceous and phytophagous. Thrips appear to be a preferred prey. Of the diets tested, pollen + thrips was most suitable for development of nymphs whereas green bean + pollen + thrips was the best diet for increased adult longevity and total egg deposition. The significance of omnivory in predaceous Hemiptera is discussed.