This paper is conceed with the bionomics and demography of Pediculaster fletchmanni Wicht (Acar: Siteroptidae) under controlled conditions (20 ± 1, 22 ± 1 and 25 ± 1℃, 70% ± 5% relative humidity and a photoperiod of 16L: 8D hours). Glass Petri dishes inoculated with Trichoderma sp. mycelia were used as substrate and food source. The mean developmental time of the egg and the active larva did not differ significantly at the various constant temperatures, but these periods were significantly different for the quiescent larval stage. The preoviposition period ranged from 2.3 to 2.8 days, the ovipositional period increased with temperature increase, and all females died immediately after oviposition.The development of active larvae was the fastest of all life stages. The developmental threshold ranged between 5.25-14.22℃ the highest value being observed for the quiescent larval development. For immature development required 89.29 degree-days. Values of rm (intrinsic rate of increase) were 0.229, 0.398 and 0.386 for 20, 22 and 25℃ respectively.Finite rates of increase (λ) increased along with increasing temperature from 20-25℃consequently the population doubling time (Dt) and mean generation time (Tc) showed significant differences with increasing temperature.