Background: The pine processionary moth (PPM) is an important insect defoliator of pine trees. This pest is commonly found in natural pine stands, plantations and ornamental trees in European cities. The urticating setae released by larvae cause severe health problems to humans and animals. With climate change, the PPM phenology is getting more and more variable. As a consequence, the number of urtication problems is increasing and the Bt spray is less effective. Here, we aim at presenting preliminary results and our perspectives on how climate change affects this insect’s phenology. Materials/Methods: Experiments will be done in incubators to assess thermal needs of several developmental stages (eggs and larvae). These data will feed a phenology model based on performance curves. Phenology data will be collected on the field to validate the model in different bioclimatic regions. The timing of adult emergences will be monitored using pheromone traps. To monitor processions, we will collect bags of procession traps every week to check the capture of processions, and we will install cameras in these traps to determine a posteriori the date of procession. Besides, to apply the phenology model, the influence of the silk nest on the actual temperatures experienced by larvae has to be taken into account. We will therefore model the deviation between air temperature and temperature in PPM nests. Results and discussion: Although this work started in autumn 2018, we will present preliminary results on field observation. We will present phenology data collected in the 1970s in different bioclimatic regions in France, data collected during the last years, and the changes observed in temperatures. Conclusion: A phenology model is a key milestone for the understanding of the PPM response to climate change, as it will enable providing decision-support to adequately time Bt sprays, as well as alerts for urtication risks.