Development, survival, and reproduction of the psocid Liposcelis decolor (Psocoptera: Liposcelididae) at constant temperatures

Abstract

The development, survival, and reproduction of Liposcelis decolor (Pearman) (Psocoptera: Liposcelididae), an important insect pest of infested stored products, were evaluated at eight constant temperatures (20-37.5°C). Female L. decolor had four nymphal stadia, whereas males only had three nymphal stadia. Between 20 and 37.5°C, the female developmental period from egg to adult varied from 46.2 d at 20°C to 16.1 d at 35°C, and the male developmental period from egg to adult varied from 41.8 d at 20°C to 13.6 d at 35°C. Based on a nonlinear model, the lower temperature developmental thresholds of female from egg, first through fourth stadia, and combined immature stages were estimated at 12.22, 16.08, 10.93, 8.88, 12.64, and 13.02°C, the upper temperature thresholds were 42.11, 39.44, 41.27, 40.92, 39.20, and 40.52°C, respectively, whereas the lower temperature thresholds of males ranged from 11.68 to 15.86°C, and the upper temperature thresholds ranged from 40.19 to 42.04°C. The survival rate from egg to adult was 57.3% at 32.5°C, 38.4 at 20°C, and 19% at 37.5°C, respectively. After emergence, the adult had a preoviposition period that ranged from 6.8 d at 20°C to 2.3 d at 35°C. L. decolor produced the most eggs (130.4) at 32.5°C and the fewest (24.7) at 37.5°C. The population reared at 32.5°C had the highest intrinsic rate of increase (0.0609) compared with the populations reared at seven other constant temperatures. The populations reared at 35 and 37.5°C had type III survivorship pattern, whereas populations reared at other temperatures had type I survivorship curve as determined by a Weibull frequency distribution. The optimal range of temperature for L. decolor population growth was 27.5-35°C. © 2008 Entomological Society of America.