Insect development is heavily impacted by temperature and the development time could vary across life-stages. In the literature, two types of model are generally used to simulate insect development: 1) linear models that are easy to use but not reliable near developmental limits and 2) non linear models that are more robust but need substantial datasets to be correctly parameterized. The good practice is to test both types of models and compare their predictions to find the best model. The pine processionary moth (PPM), Thaumetopoea pityocampa, is an important forest pest in Europe currently expanding its range with climate warming. Due to its univoltine development, this species is also suspected to respond to climate change with shifts of its life cycle depending on climatic features. To simulate PPM phenology, we built three phenology models: 1) a linear model based on degree-days needed to achieve the development of each life stage, 2) a non-linear model based on the thermal performance curve (TPC) of each stage considering hourly mean temperatures, and 3) a non-linear model also based on the TPC of each stage but considering daily mean temperatures. To compare the accuracy of each model, their predictions were compared to phenological observation data. The non-linear model with daily mean temperatures was found to best fit the observations. This model was used to explore the effects of climate warming on PPM phenology.