The South American tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), invaded Algeria in 2008 and caused severely significant devastation to tomato plants. This study designed to evaluate the thermal requirements and assess the influence of temperature on the life cycle of this devastating pest under controlled greenhouse environment. Through a series of experiments, we observed four generations of T. absoluta at various temperatures and relative humidity levels. We chased the population dynamics by using pheromone traps and revealed four overlapping generations, each of which corresponded to peaks in adult flying activity. These peaks were influenced by the greenhouse's temperature and humidity levels. The development of successive and overlapping generations of T. absoluta requires temperatures ranging from 25 to 30 °C, coupled with humidity levels between 58.5 % and 69.33 %. Additionally, the morphometric analysis of T. absoluta larvae allowed the identification of four larval stages characterized by lengths of 2.5 mm for the first instar, 2.5 to 4 mm for the second instar, 4.5 to 5.5 mm for the third instar, and 6 to 7 mm for the fourth instar. By studying the biology of T. absoluta and its thermal and hygrometric requirements, we can develop an integrated pest management strategy that efficiently battles against this destructive pest.