There is still a substantial lack of knowledge about the effective impact and the ecology of the seed bug, Leptoglosus occidentalis, on the Mediterranean stone pine. Thus, the overall objective was to characterize the impact and study the ecology of this invasive insect in stone pine by (1) characterizing its damage on seeds with shell; (2) testing its preference between stone pine and other Mediterranean pines; (3) evaluating damage in Stone pine seed orchards under different management strategies and (4) inferring invasion routes of this insect in the Iberian Peninsula using genetic and field data.