Effects of constant temperatures on development of the psocid Liposcelis fusciceps

Psocids of the genus Liposcelis (Psocoptera: Liposcelididae) have become serious stored-product pests worldwide and usually infest storehouses, grain processing facilities, and product warehouses. Large numbers of Liposcelis fusciceps Badonnel have been found infesting grain processing facilities in the U.S.A. To effectively manage this psocid pest, information on its biology is vital. Therefore, we investigated the effects of six temperatures (22.5, 25.0, 27.5, 30.0, 32.5, and 35.0°C) on the development of L. fusciceps at 75 % RH. Expectedly, temperature had a significant effect on the development of this psocid. Developmental time from egg to adult for female L. fusciceps decreased with increasing temperature, and was shortest at 35°C. L. fusciceps males have two to four nymphal instars, and the percentages of males with two, three, and four instars were 28, 69, and 3%, respectively. Female L. fusciceps have three to five instars, and the percentages of females with three, four, and five instars were 22, 71, and 8%, respectively. We developed temperature-dependent developmental equations for male and female eggs, individual nymphal, combined nymphal, and combined immature stages. Our results can be used to predict L. fusciceps population dynamics and to develop effective management techniques for this pest.