The anthocorid, Orius insidiosus (Say), has been identified as an important predator of soybean aphid, Aphis glycines Matsumura, in soybeans, Glycine max (L.). The presence of O. insidiosus early in the soybean production season has suggested it may be key to the suppression of soybean aphid population growth in the soybean crop. Soybean thrips, Neohydatothrips variabilis (Beach), are an important alternative prey item commonly eaten by O. insidiosus in soybean fields. Alternative prey can affect the ability of generalist predators, like O. insidiosus, to exert control of pest populations in both positive and negative ways. As a result, we initiated studies of the life history characteristics of O. insidiosus to determine how consumption of soybean aphids and soybean thrips affected the predator’s survival, development, and reproductive rates. Experiments were conducted under controlled laboratory conditions and involved feeding O. insidiosus various levels and combinations of prey. Predators feeding on 1 aphid per day exhibited significant decreases in longevity for nymphs, whereas adults fed 1 soybean aphid daily showed significant decreases in longevity and fecundity compared to predators fed 3, 6 and 12 aphids daily. Orius insidiosus nymphs fed 1 soybean thrips every other day exhibited significant decreases in longevity, and failed to complete development to the adult stage compared to nymphs fed 5 and 20 thrips daily. Experiments involving O. insidiosus adults fed soybean thrips and combination diets are on-going. Data from our life history study will be used to understand this predator’s adaptations in soybean fields, and contribute to models of predator-prey dynamics in soybean fields.