A computer model for simulating population dynamics of Lyctocoris campestris (F.), a predator of stored-product insects, was developed using data from the literature and newly collected data for adult longevity and fecundity. Immature development time and survival, adult longevity, fecundity, and cannibalism were simulated. The model was validated at ambient environmental conditions during three seasons in Wisconsin. The model accurately simulated development of the predator feeding on larvae of the Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), in the validation studies. The model will be useful in optimizing mass-rearing and augmentative releases of this predator for biological control of stored-product insect pests.