The development, survival, and reproduction of Liposcelis paeta Pearman (Psocoptera: Liposcelididae), an important insect pest of stored products, were evaluated at nine constant temperatures (20-40 degrees C). Few insects could complete the development or reproduce at 20 or 40 degrees C. Between 22.5 and 37.5 degrees C, the developmental period from egg to adult varied from 45.4 d at 22.5 degrees C to 11.5 d at 37.5 degrees C. The lower temperature developmental thresholds were estimated at 18.1-21.9 degrees C, and the upper temperature thresholds were 40.4-42.0 degrees C. The percentage of survival from egg to adult was 52.79% at 32.5 degrees C and 18.79% at 22.5 degrees C. After emergence, the adult had a short preoviposition period that ranged from 6.3 d at 22.5 degrees C to 0.8 d at 37.5 degrees C. L. paeta produced the most eggs at 27.5 degrees C and the fewest at 37.5 degrees C. The population reared at 32.5 degrees C had the highest intrinsic rate of increase compared with the other temperatures. Based on our data, the optimal range of temperature for L. paeta population growth was 30-35 degrees C. These data give us better understanding of L. paeta population dynamics, and they can be used to develop effective management strategies for this psocid.